Can a 12V LiFePO4 Battery Replace the Lead Acid Battery in a Car?

[@rlordonio]

I directly replaced my car battery with a 46AH Lifepo4 battery in June 2018 out of curiosity. It only lasted for 3 years (until July 2021) when I expected it to last for 10 years! It was still able to start my car until the end but what I noticed was the engine stalls while we were on neutral in the middle of traffic. When I replaced my battery with SLA, my car went back to normal.

[@davidniquot6423]

My Pb battery in my Bmw lasted for 14 years before being too weak to crank the 3l engine, it's still in use (18 years old now) to power a water pump (20Watts) in my garden, it's charged with a PV and a charge controller. Big advantage of this car (and some others) the battery is INSIDE the car and is kind protected from the elements.

[@АнтонКраценюк]

It would last if it was 100 ah lifepo4

[@ladjkaoz]

Did you wired 4 cells in series, I have a 2012 128 I may try this. Didnt you got any engine codes, BMWs are so monitired, im surprice if you didnt got a service light warning.​@davidniquot6423

[@wy3492]

Thank you for taking the time to explain this so clearly. I have always wondered why I cannot use a LiFePo4 battery for my car or boat as a starter battery. The manufacturers always recommend to use it only for a trolling motor of a boat. Thanks again, I was still planning to try using a LiFePo4 battery as my starter battery. Now I understand what can happen, so I definately won't do it.

[@dantronics1682]

there is nothing to stop someone with a bit of brains to modify the charging circuit of the car to charge the lfp battery.

[@MiniLuv-1984]

Excellent overview of using a LiFePO4 as a starting battery - fets, under bonnet heat, low temperature performance and charging - kudos to your thorough and accurate knowledge and simple, well delivered explanations. Your honesty in outlining the limits of your knowledge is commendable too. There is a reason why I rush to see your videos, this probably has a lot to do with it.

[@StanleyPhua]

Just want to share my experience. To cut story short. Recently caught a hit and run case while parking, therefore decided to build a 125A lifepo4 battery with a BMS can handle 200A discharge to replace my Lead starter battery, so I can run my 3 car cams 24/7 for week without worries. I am using for two months now, so far very satisfied with the battery performance. Tips and my finding. 1. I add a super capacitor (360F x 6 nos, 16.2V60F) in parallel to the battery with 60A fuse. Reason is to help to jump start the engine (although I know my 200A lifepo4 battery is strong enough to handle the 2.0 Camry starter that will draw around 180A+-), second to buffer the voltage from alternator, also sudden cut-off from BMS ( Do it based on instinct). 2. I also add a TVS diode at the alternator to protect the alternator from the back emf if the battery turn-off by the BMS while running. (Based on research, and hope my research is correct) 3. I set the single cell over voltage at 3.65v and low voltage protection at 3v to prevent frequent on-off of BMS. Nevertheless I set my pack over voltage at 13.9v and turn-on charging voltage at 13v. Reason been the alternator voltage is always fluctuating, so when BMS sense 13.9 volt, the BMS turn-off the charging, the lifepo4 battery will has a voltage reading around 13.3v or 13.4v volt which is around 80% to 90% SOC. When the battery fall below 13v (around 40% SOC) the BMS will turn-on and start charging again. The main reason I doing so is because I want the battery to always fall between 90% or 80% to 40% SOC so I can enjoy max charging cycles of 4000 or more. 4. I stay in Singapore, base on my observation, my Lifepo4 +ve terminal, Battery and BMS temperature is around 50+- degree celsius, the battery will get hotter to around 56 or 57 degree celsius when parking. Therefore I have a build in Thermostat switch (activate at 55 degree celsius) to activate a 12v mini fan to cold the battery down. So far I only experience it turn-on one time while I am parking.

[@overbuiltautomotive1299]

cool i like to do the same God bless sir

[@elixier33]

Cold the battery down?

[@SocialPerspective101]

When BMS switches off charging, does the battery remain connected to the system to act as capacitor?

[@CadeBrazil]

maybe a dc-dc charger (renogy or victron) can save alternator and use those BMS with direct negative power.

[@jacobclark89]

Thanks !

[@geraldkoth654]

Very good explanation of the differences in LiFePO4 and Lead Acid. I build my own LiFePO4 batteries and do not use a BMS. I use them to power all sorts of things, even to start the outboard motor on my boat. I have specific chargers for LiFePO4, I use QNBBM balancers to keep cells in balance during charging and discharge. I monitor voltage of the batteries during use and storage. I have been following battery technology for five decades. Do not just go putting this that or the other thing batteries into use unless you understand all the factors necessary. Any battery with sufficient energy to start a large engine can also quickly start a large fire.

[@seunggonlee4896]

The JOMBI EV PRO product, manufactured and supplied by Taebaek Corporation in South Korea, offers lithium iron phosphate (LiFePO4) automotive starter batteries that are of far superior quality compared to any lead-acid battery. Our batteries can be exchanged 1:1 with existing lead-acid batteries, functioning perfectly as automotive starter batteries without any issues. They have an expected lifespan of over 10 years. Our patented circuit technology ensures perfect operation without strain or abnormal behavior in the vehicle, preventing overcharging due to voltage differences between internal cells. The patented circuit also provides complete protection against cell balancing issues that may arise in vehicles with overcharging. Our products are designed to be fully compatible with any vehicle manufacturer. Utilizing next-generation AI technology, our lithium iron phosphate batteries are designed to showcase their inherent technological advantages without the need for separate design or operation.

[@JonnyWaldes]

use a BMS sir. they are really cool for one thing and safer!

[@lasersbee]

I've been using a LifeP04 8AH battery to start my 54" Zero turn 27HP Lawnmower. I also use a LifePO4 8AH battery to start my 15HP Hydraulic Power Pack. So far I've had no problems. This summer I'll be testing the same 8AH LifePO4 Battery on my Harley. Of course all my uses are only during the warm seasons

[@fredio54]

Find my longer comment above/below - I don't know what's in your pack but it sounds suspiciously like the 10 or so I have on my vehicles and vessel.

[@MrRobertPogson]

Of course LiFePO4 can be used to start engines, but they are not drop-in replacements for lead-acid for the reasons given. They do offer advantages of size, lifespan and weight but the cost of temperature management and appropriate battery management likely make that use impractical. Anyone who keeps their vehicle or engine in a heated space would have an easier time. I doubt batteries in most cars would overheat in a temperate climate. LiFePO4 cells have very low internal resistance so starting current is not an issue given reasonably large cells or cells in parallel. Starter circuits have their own solenoid switches so the BMS does not need to handle starting current, just charging currents and other loads. Temperature monitoring, load monitoring and voltages give a good enough indication to a BMS to regulate charging.

[@fredio54]

@@MrRobertPogson Whilst all of that is potentially true, in the real world I have ten (10) cars with LiFePO4 without BMS with active balance while running and low drain when not or isolate to prevent over discharge and readiness for next time. The cars I use weekly or more are just left connected, the ones that sit for longer are disconnected. Reality is an alternator can only do ~100A so if your cells can stomach that then you're good to go. 14.6 is max charge, but you'll get a full charge at much lower voltages, so as long as your alternator is behaving itself inad in the 13.8-14.4 range you're 100% fine. The trouble with BMS use for the charging current and rest of the loads in the car is that the BMS drains the battery itself - there is no solar array here. In my vehicles nothing except the clock and stray leakage current from moisture and ECU memory current drains the battery and even tiny 8AH and 16AH packs are reliable for me in terms of not being drained over short periods. One of those cars I'm going to change to a large capacity LiFePO4 pack just because the trip counters reset to zero on disconnect and I don't use it often but want to track fuel spend vs mileage - so a small isolated pack is not well suited to that car. I've been doing this for over 2 years now and I fully expect these cells to be at my funeral still able to crank over any reasonable engine and some unreasonable big ones aside.

[@SocialPerspective101]

@@fredio54 Don't u need a current limiter to ensure alternator does not get overworked?

[@solar24gr]

Lifepo4 battery for car starter use must be without bms but with active balancer and will be 🙂

[@fernandoesteban2345]

I just built a Lifepo4 12.8v battery pack and use it without a BMS and put an active capacitive balancer to keep the cells balanced. It's installed on my 2005 Ford Ranger with the WL diesel engine. It works just fine and has done so for a couple months. I'm in South East Asia.

[@sanzvlogs5157]

please share your build

[@seunggonlee4896]

@@sanzvlogs5157 The JOMBI EV PRO product, manufactured and supplied by Taebaek Corporation in South Korea, offers lithium iron phosphate (LiFePO4) automotive starter batteries that are of far superior quality compared to any lead-acid battery. Our batteries can be exchanged 1:1 with existing lead-acid batteries, functioning perfectly as automotive starter batteries without any issues. They have an expected lifespan of over 10 years. Our patented circuit technology ensures perfect operation without strain or abnormal behavior in the vehicle, preventing overcharging due to voltage differences between internal cells. The patented circuit also provides complete protection against cell balancing issues that may arise in vehicles with overcharging. Our products are designed to be fully compatible with any vehicle manufacturer. Utilizing next-generation AI technology, our lithium iron phosphate batteries are designed to showcase their inherent technological advantages without the need for separate design or operation.

[@lloydthegreat7851]

You're 100% correct about not disconnecting a battery while the engine running. The battery just in its inherent design absorbs those spikes that you know we see on the electrical system.

[@unionse7en]

I've used very small LIFEPo4 batteries as the sole automotive battery. Above freezing it's simple. I've put a lot of thought into doing it below freezing, but it adds a lot of complexity. Smart management,insulated battery box with electric heater...and possibly running warm coolant into that box as well....

[@wyslink9354]

carry the battery inside the house with you lol. Hook it back up every morning xD or maybe gank some parts off of a Tesla ?

[@christiano.4808]

Good video! For everyone asking this question, it's important to understand that there are different types of LiFePo batteries. There are different types of cells and different BMS'. In general, LFP batteries can be used in your car. I think it was Porsche who even started fitting LFP batteries to some of their production cars many years ago. But most of the batteries reviewed here cannot be used for all the mentioned reasons. You need the right cells, there are LFP cells with a charging temperature of down to -20°C and end of charge voltages of 4V, and the right BMS or just no BMS at all. A BMS is usually there to protect the battery from situations which are considered normal workload in a car, so most BMS' will just interfere with the normal operation and might stop you from using your car. So, if you desperately want to do it, get the right parts needed for the job. But, don't forget that your car battery is subject to excessive wear in normal operation and will be consumed over time. Switching from LA to LFP will not change this.

[@jfbeam]

Also, a proper Pb-acid battery is MUCH cheaper. (and can be found at any autoparts store.)

[@dantronics1682]

@@jfbeam a Pb is 5 times the weight of an lfp and the lfp even though more expensive may last a lot longer than the Pb, slight modification of the charging circuit is all thats needed

[@Ferdy00F]

@dantronics1682 what modification?

[@Josh-py2in]

I would really like to see you open and look at the Antigravity lithium car battery. They're very expensive and seem to get a lot of positive feedback. They have some pretty great claims too.

[@seunggonlee4896]

The JOMBI EV PRO product, manufactured and supplied by Taebaek Corporation in South Korea, offers lithium iron phosphate (LiFePO4) automotive starter batteries that are of far superior quality compared to any lead-acid battery. Our batteries can be exchanged 1:1 with existing lead-acid batteries, functioning perfectly as automotive starter batteries without any issues. They have an expected lifespan of over 10 years. Our patented circuit technology ensures perfect operation without strain or abnormal behavior in the vehicle, preventing overcharging due to voltage differences between internal cells. The patented circuit also provides complete protection against cell balancing issues that may arise in vehicles with overcharging. Our products are designed to be fully compatible with any vehicle manufacturer. Utilizing next-generation AI technology, our lithium iron phosphate batteries are designed to showcase their inherent technological advantages without the need for separate design or operation.

[@pawelallable]

I have a lifepo4 battery in my motorcycle, and it's been a great improvement over lead acid. It feels a little weak when cold, but running the headlight for 30 seconds first seems to warm it up and get it going hard and starts great.

[@James-fe7wd]

Bro you deserve in anstant like just for covering this topic. There are so few experts talking about all the complications to it in any serious detail, but you've done a stellar job. Thanks! There are discussions of how the BMS will accept a typical AGM charge profile up until about 70% - which is considered by many to be an benefit to extending the battery life of a LifFePO4 battery since they view fully charging it as something that compromises its lifespan. And then there are DC-DC chargers which are developed specifically for the purpose of charging alternative battery types from a lead acid charge profile. I'm sure some of them pull the voltage up from what the car charging system wants to feed it, and additionally they govern the charge voltage being used to charge your chosen battery type. They're not cheap, but they are pretty smart devices, a lot of people use them for charging their boats and camper van batteries, etc. The great thing about them is that they wont stress out your battery or alternator if you use one, even if you're using a lead acid for a starter battery and are charging a seond LiFePO4, a decent one will do the job gracefully. It may even save you having to upgrade your alternator. One more complication you may have is that a lot of manufacturers will give you a warranty of a certain time, or a certain number of discharge cycles. If you are not discharging the battery and then recharging it many times a day, you may be shortening the battery's warranty considerably - but thats the fine detail I'm really not sure about, I need to get around to asking them what they consider a 'discharge cycle'.

[@scotwilliamson1095]

I have a super cap under hood and small LifePo4 under back seat. When truck is off, they are in parallel. When truck is on and above 13v they are separated and charged independently. Also have temp sensor on the lifepo4 that switches between charging/heating. Going almost 3 yrs now. Expensive but I'll never have to buy a battery again. -- Love the supercap. Sat in parking lot after work one day watching someone try to jump off a truck that had left his lights on. After 15min of just hearing them getting nothing but clicks, clicks. I drove over, said hold my beer. Hooked cables to my truck, it started instantly. They both just stared in shock at how awesome Toyota trucks must be to be able to do that. I didn't tell them about my secret 10,000 amps. lol -- Must careful with what you "jump"/"power" though, A non resistive or non amps limited load will let the smoke out before you had intended.

[@Brandon_Nelson92]

What did you use for your super caps? I'm an electrician and am planning this kind of setup for my truck. I was planning on using bank of either 6s1p or 6s2p 2.7v 3000f super caps. Is 6000f overkill for an f150?

[@scotwilliamson1095]

@@Brandon_Nelson92 I used prebuilt cap from xspower. It's a 6s1p of 3000f caps. Which is overkill as far starting power goes, literally says on it "10,000amps". But I've seen those $50 ebay 6s1p diy caps of 500f do the same job. So either would be enough starting power even if it said Cat on the engine.

[@hywelda]

Hope you do a video, narration and/or picture/print publication! A project well worth sharing!

[@zaksaas8233]

Last 4 years, I am using supercapacitor parallel with lead acid battery. It take 4-5 year to replace one lead acid battery instead 1-2 years without supercapacitor. Now I am using LiFePO4 and supercapacitor. My main battery is supercapacitor. My LiFePO4(with bms) is backup for supercapacitor (using resistor to charge back supercapacitor). Charging LiFePO4 using car alternator series with diodes (prevent high current).

[@javierferrer8898]

You should test antigravity car batteries lifepo4 chemistry. BMW and other car manufacturers have been using lifepo4 with success for years. Many autocross racers and track cars use antigravity batteries since there more reliable and weight is less than lead. Hope you buy one to tear it down to see how they make them for car use.

[@JeremyAkersInAustin]

While it's correct that most LFP batteries on the market today aren't suitable for starting engines, there are plenty of LFP battery options that are perfectly capable of doing so which still have under temp charging protection and good CCA outputs. I have several vehicles with LFP starting batteries: 1.) A Farmall Super H tractor using an EarthX battery (Which are actually designed and approved to crank aircraft engines where they see very cold temperatures). This battery has been in service since 2018 with no issues and has started the tractor in zero degree weather. 2.) I have a diesel motorhome with a 6.6L diesel engine. I replaced the two lead acid batteries with two Banshee Lithium Starting batteries. These have been in service since 2019 with no issues, and have started the engine in zero degree weather many times. 3.) I have a diesel Jeep Liberty where I replaced the lead acid starting battery with a Banshee Lithium battery. In service since early 2020. 4.) My parents have a diesel motorhome where they replaced the two lead acid starting batteries with two Dakota Lithium engine starting batteries (Just installed this year so no real use on them yet) 5.) The 8kW diesel generator in my motorhome is cranked by two BattleBorn batteries, in service since 2017 and has started the generator in below zero degree weather many times over the years without any issue. 6.) I also have several smaller engine equipment like garden tillers, portable generators. All have been switched to LFP starting batteries because they last longer. None of the above applications required making any modifications whatsoever aside from swapping the batteries. The notion that LFP can't crank an engine is ludicrous. Any decent LFP battery, especially one designed for engine cranking, will have a BMS that protects against charging in cold weather and no that won't cause a "voltage spike" if the BMS shuts off charging. I don't understand where notion came from. Don't just repeat things you've "heard". If you think there's a voltage spike, prove it. Show us where the spike occurs. These FETs usually have large resistors across them so when they shut off they can still dissipate any "spikes" that might occur from the alternator. And you can absolutely disconnect the battery from a running car and nothing of any significance happens. I have done it many times when testing batteries and alternators. As long as the battery has a properly designed BMS then an LFP battery will crank a car motor just fine. My diesel powered vehicles need a lot more cranking amps than the average gas car, so if these batteries can crank a diesel motorhome in zero degree weather then I think they'll start your Corolla just fine. I have been using LFP batteries to start engines for several years now and I have not had any issues.

[@bobconaway]

@D R My guess is because they're too danmed expensive to acquire just to tear down for testing.

[@bobconaway]

Regarding the Banshee batts you use in your diesel motorhome, I assume these are Banshee's marine batteries. Because on a number of websites selling Banshee batteries there are no direct automotive (or truck) versions, which I find odd. Also, if you are using the marine batteries, they are *very* costly. I really am a fan of the LiPo batteries, but the prices will need to come 'way down for acceptance by the general public.

[@JeremyAkersInAustin]

@@bobconaway Yes, the marine dual purpose starting/deep cycle batteries. Their Group 34 version costs $600. So I can see why someone might conclude they are pricey if they didn't look any deeper. However that $600 buys you a battery with 50 usable Ah which is supposed to be good for 5,000+ cycles. A high quality AGM Group 34 costs around $300 for roughly 30 Ah usable and only good for roughly 1000 cycles at most. The AGM also must be maintained at 100% state of charge (SoC) at all times when it's not in use to maintain that cycle life, unlike the LFP which is quite happy to sit at any SoC. Sure they cost roughly 2x a "comparable" AGM battery. But if they last as long as they are projected at 5000 to 7000 cycles: that's at least 5x longer than the AGM: if you price out the cost per cycle, the LFP batteries are substantially cheaper in the long run and offer more usable Ah to boot. The LFP will give you 5000 cycles at 50 Ah per cycle = 250,000 lifetime Ah The AGM will give you 1000 cycles at 30 Ah per cycle = 30,000 lifetime Ah So the LFP will give you roughly 415 lifetime Ah per dollar spent. The AGM will give you roughly 100 lifetime Ah per dollar spent. So which one is actually cheaper? It strikes me as odd with these economics in favor of the LFP batteries that the expectation is that their price needs to come down. Why isn't the expectation that people understand the total cost of ownership of something and be educated that a higher upfront cost does not equate to a higher overall ownership cost? People already pay 2x as much for AGM batteries over standard vented/flooded batteries because they last 2-3x longer and need less maintenance... And I don't see anyone claiming that "AGM prices need to come down for acceptance by the general public" Also to be clear: These are not LiPo batteries. LiPo uses a different chemistry. LiFePO4 (aka LFP) is different from LiPo. LFP batteries last substantially longer and are not prone to catching fire like LiPo.

[@bobconaway]

@@JeremyAkersInAustin Yes, I'm also referring to LiFePo batteries. I'll not try to pick apart what you've written, but the market that will make LiFePo batteries successful is the regular old auto and light truck market, and no one is truly targeting that 800lb gorilla. Why? I maintain price is one reason (no matter the benefits), and maybe - just maybe - because all of those hundreds of millions of already-installed alternators out there do not play well with LiFePo batteries. The powersports batteries out there don't do any voltage/current regulation, just cell balancing. I suspect a person will not see the potential cycles from them, but they just don't know it yet. Stupendous cycles are great, but the other great benefit is high, even discharge over time before the voltage drop-off. Well, today's cars and trucks don't need that. RVs and some marine applications, sure. But, again, if LiFePo batteries can't sucessfully meets the needs of the existing car and truck battery replacement market, they will not succeed. They will be a niche product, and will not attract the big investors. Therefore the prices will remain high. Vicious cycle.

[@kornshadow097]

What's a "FET"?

[@wasifksyed]

Well, I have been doing it for many years. I will never use small cells with lower amp rating. I have 90AH plastic CALB Lithium iron phosphate cells in 4S configuration with 100 amp Daly BMS and 5A capacitive active balancer. Initially I had no BMS and I was overcharging some cells. Relocate your battery to trunk if you are concerned about high or low temps. These cells have no problem discharging at low temps just charging is disabled at low temp by Daly BMS. But as temperature rises the BMS will let it charge. Cranking amp at 3C of 90 amp or 270 Amp is not a issue. Honestly lead acid batteries are vulnerable to temps too. I was tired of sulfation and short storage life. As far as Alternator goes, you only need to worry about it failing if it is trying to charge a dead battery. But if you have a solar or plugin trickle charger than that is not a issue. Daly does allow you to set high amp disconnect. So set it low if you have a small alternator. I did upgrade mine to 200a alternator. Voltage is fine. My alternator goes to 14.3v and if cells are balanced than it has no issue. I did have to parallel two 100amp Daly bms to support higher cranking amps. They do have no problem with 150 amp surges. There is also a QUCC bms with contactor that can handle higher amps, But it will completely disconnect both charge and discharge circuits. Lead acid is old technology and lithium is the future. Now if you have not seen a out of box solution it does not mean it cannot be done.

[@arebear4797]

good one bro. me the same.

[@azmisalleh6465]

Me too. Going to 8 months now. No problems at all.

[@dobrzpe]

i was hoping you'd see this video and comment. glad you can still start your hummer. how were you able to tune your alternator to only 14.3v? thou you did admit to not using a BMS and overcharged some cells... how did that happen if your alternator 'only' goes to 14.3? even if you use a dc-dc converter, ALL the other problems are still there.

[@wasifksyed]

@@dobrzpe Just buy Invicta battery. Voltage regulator maintains 14.3 as it does for lead acid battery. But not all cells are designed the same. So if you are scared than just buy prebuilt.

[@kornshadow097]

Out of the box and stock items are for normal sheeple. Not us.

[@MrTespro]

This is the best explanation I've seen yet as to the many inherent problems in this goal. I wish he would experiment with the addition of super-capacitors to see if the combination works - and, if not, why. Ruining your car's electronics is a REAL issue!!!!

[@pofjiosgjsoges]

I remember a video where the lead battery was replaced by a bank of supercapacitors, with the support of a small lipo battery for voltage recharge. If it weren't for the price of supercapacitors, you could create such batteries for cars. There was "1 year update" and it was working just fine

[@Josh-b3c]

Yes they had the super capacitor wired directly to the starter only and then the lipo pack was in place of the lead acid then there was a separate charging circuit that ran off the lipo to charge the super capacitor

[@hippie-io7225]

Laser Saber channel

[@WTF_BBQ]

I remember those videos. I was actually curious about the lithium battery because those things don't like extreme temperatures. The engine bay is definitely a bad place for it.

[@dantronics1682]

@@WTF_BBQ is it impossible to place the battery elsewhere? my battery is in the boot since there is no place under the bonnet for it but even in a cheap car the average person could move the battery if he wanted to, if he is not capable of doing such a simple task he shouldnt be messing with the car in the first place

[@WTF_BBQ]

@@dantronics1682 I don't know where else you would put it. Inside the car can get very hot during the summer. I had some lithium batteries in the car before and it damaged the batteries over the summer. if for some reason the lithium ignites spontaneously, it'll definitely be a bad day.....

[@GordLamb]

Holy market opportunity. It's utterly *trivial* to design a lifepo4 battery for automotive use. For below-zero (and >14.6V) charging, shunt excess current into a warming circuit. Use a contactor instead of mosfets for disconnect. Monitor the terminal voltage for reengagement. Outstanding and accurate video as always. :) I'm just amazed how *bad* lifepo4 battery manufacturers are at producing reliable products, generally speaking.

[@otm646]

Dakota Lithium has had the DL plus line out since early '23. They specifically designed exactly for this application. You hook them straight up to the alternator like a lead, acid drop in replacement.

[@uhjyuff2095]

I have not tried this, but if you connect a lifepo4 battery in parallel, there is small risk of losing 12v supply and your lead acid battery will last forever because it will basically be in float stage and never discharge even when the starter is used. It would be cool because you could turn the car off and still have a large battery system without the added weight of heavy AGM deep cycle batteries in the trunk!

[@ladjkaoz]

Doesn't batteries die or lose life as they age from production date. Regardless of use.

[@FreeClimbersNet]

Excellent update on these batteries thank you. Easiest solution seems to be just replace your flooded with flooded, and be done with it. No automobile sensors, switches, or expensive mistakes to worry about. On the other hand, that alternator is there, so why not just use it a little differently? You can. But it's going to cost you. It would be a fun project, as some of your commenters have informed with their elegant solutions. This problem seems to beg an aftermarket fix.

[@stubbshomestead1316]

Wonderful topic I've been wondering the same thing, Thank you! I've personally used the battery tender one on my motorcycle and I had no issues with it for the 2 years I had it. I just bought a lithium starter battery for my lawnmower so I'll see how that goes.

[@joebidendidthat5121]

Great video. I installed a Shorai lithium in my Harley RoadGlide 7 years ago. It’s still going string and has never given me any issues at all. I installed after my original Harley brand lead acid battery failed at 2.5 years. I bought the bike new. I do use a lithium specific smart charger on it daily. Love the battery and the charger. The performance and longevity has been stellar. Costs more but appears to last much longer.

[@DavidChatenay]

Good video! I've been eyeing the Antigravity batteries for a while now. It looks like the company built their own BMS, and took into account a lot of the issues you describe (cold, thermal overrun, engine heat etc). They're expensive though, I would love to see a teardown on one of these!

[@wyslink9354]

shorai also has a 36ah with [540 cca] I was just comparing with an antigravity ATX20-RS, similarly priced. Both only cost between $2-300

[@davidniquot6423]

The chemistry do not permit the use in automotive... no matter what you do .. LiFePo4 is not suitable .... ! Appart from buidling an overcomplex device that would heat hitself and waste energy between 2 use of the car/bike.... The company you talk about is just .... lying and they even put a high price to convince some other people ... lol ..

[@JeremyAkersInAustin]

@@davidniquot6423 I've been using LFP batteries to start tractors, diesel trucks, and other vehicles for many years. So please tell me more about how they aren't suitable.

[@bdjm8595]

Really excellent explanation of how and why Lithium batteries are not suitable for automotive use, thanks!!! As an aside I have run into folks who try to use deep cycle batteries to start their diesel pickups. It might work in the summer but when you need a LOT of POWER in the winter they just won't do it.........but they still won't believe me when I tell them not to do it!!!

[@LithiumSolar]

Yeah... they won't understand until they actually try starting one when it's cold. I killed the batteries in mine just a couple of weeks ago trying to start it when it was 5F overnight. That's the first time it's ever failed starting. Need to get me some new/better batteries soon for sure.

[@bdjm8595]

@@LithiumSolar Use your block heater!! Wired up to my block heater plug are a trickle charger to keep the batteries topped up and I have also installed a 50 watt heater in the pan of my transmission. A couple of hours in the morning before work and it starts right up and purrs like a.......tiger !!!!

[@kswis]

I have a car audio habit. Collected 240ah of the headway cells. I Paraleled them last spring to help the 630 farad ultra cap and 2 decent sized agm batteries. They worked great all spring feeding amps making around 8k or 9k watts. They did get warm in the summer so I added ventilation, a push and a pull fan controlled by a thermostat. Worked great all summer and fall. Since winter didn't really start here till about a month ago cold wasn't a worry. I pulled them all out when the forecast deemed it was time. I wish I had used LTO. They simply don't care about utah cold. At first I had active balancers on every pack but tried without and it had little affect. Moving only 2 amps is miniscule compared to the amount of variation they went through when the subs are dancing and they did stay within .25 of eachother since i balanced them thoroughly. I am going to do a capacity test to see if how much the abuse took out of them.

[@RoaldKoger]

I don't see any added value in LiFePO4 for starting a car, but well-known European supplier GWL sells them. They are Winston/Thundersky batteries without a BMS and can be used for starting small private planes. Big advantage there is the limited weight compared to SLA.

[@DSmartLife]

Right to the point! And also the Alternator will go up in smoke while charging if the LFP battery is fairly discharged due to the low IR unlike Lead acid.

[@vladbagdasarov1672]

Just install an inline dc charger to control the amperage going to the battery.

[@LithiumSolar]

If you need to monkey with the charge circuit to get it working, why not just put in the lead acid battery it was designed for?

[@vladbagdasarov1672]

@@LithiumSolar Because lead acid is an inferior battery by pretty much every metric, especially when considering their skyrocketing prices and lack of capacity for something like an overland vehicle. In the space of a standard 27F or H7 lead acid you could fit a 300ah LFP

[@JeremyAkersInAustin]

This is more of an issue with boats and RVs with massive house batteries that are hundreds of amp hours and connected to the alternator with massive battery cables. These batteries are often fully depleted before the engine is started to recharge them. These batteries can pull max amps from an alternator for hours on end which is what can burn up the alternator. When using LFP as a starting battery the battery is typically much smaller (Usually less than 100 Ah) and it's usually at or very near 100% SoC when you crank the engine. Cranking the engine uses only a fraction of an amp hour so after you start the engine the alternator is typically just topping off the battery and not running at full amps for a long period of time. The charging wiring from an alternator to a standard car battery is also not massively oversized 4/0 wire like it often is in the RV/Boat use case. It's usually like 4 to 6 gauge which increases the resistance enough to prevent the alternator from running at max amps. I have multiple vehicles with LFP starting batteries and this has never been an issue on any of my vehicles.

[@koyamamoto5933]

Great points. The application where I think LiFePO4 type batteries are feasible are in hybrid or full electric cars where there is no starter circuit being driven by the 12V battery. Temperature ratings & charging circuitry would need to be addressed. As the various hybrid or plug-in hybrid or full electric vehicles become more mainstream, the value of keeping lead-acid tech in place seems to diminish.

[@gnramires]

Here's an idea how it could work: When below freezing, a battery should have a heater and keep its temperature above freezing. When it gets near depleted (say 50% SOC), it should turn itself off and wait for demand. When it's needed again (when you want to start the car), it should refuse to work (provide no current) but start heating itself, such that if you waited a few minutes your car could start, once the battery is warm. You could use an app to configure things. Special safety measures could be taken to prevent disconnection when the car is running, probably add a supercapacitor just for safety measure and maybe a redundant BMS. Cars have many safety features already, electronics can be quite reliable.

[@elixier33]

Yes these type of batteries have existed for years.

[@JeremyAkersInAustin]

They already have this. And the design is much less complicated than what you describe: Batteries with internal heaters typically only provide heat when the battery is being charged. IE: Since the cells can't accept a charge when cold: The BMS essentially redirects that charging current to the heaters. Once the cells are warm enough it turns off the heaters and lets the energy flow into the cells. Since the heaters only operate on power that comes from the charger/alternator: there's no need to worry about them running the battery down. And these batteries also self-heat when cold, so there's no need for it to "refuse to work". A cold LFP can still crank a motor. I've used LFP batteries to crank motors as low 0F. And even if it couldn't: the act of trying to crank the motor creates a lot of heat within the cells (self warming) so even if an LFP is too cold to crank a motor, give it a couple tries and it will generally warm itself up to get it cranked over.

[@JM-yx1lm]

You're probably the smartest lithium guy on KZbin and we have a serious problem... Will and watts247 started a raging fire yesterday involving the 5000es inverters that millions of people have bought, we need you to explain the situation to us and some kind of solution to make these somewhat safer for us. Please.

[@DSmartLife]

Yes you are right, we need LithiumSolar's take on this issue. I think it's a huge safety hazard, Ian's also right about the transformers back feeding each other in bypass mode, leading to overload and heating up house wiring. Another concern is the unnecessary additional power loss due to the AT especially while running inductive and other low power factor loads. Anyways for those who are desperate for a solution using their existing AT and EU inverters, unbond the ground like Ian did and wire the AT only during inverter mode, bypass AT during grid input available. This can be achieved by using additional bypass relays or by rewiring the inverter output itself (internal output) and use the internal inverter bypass relay. I don't see any other solution using AT. Complicated solution though.

[@uhjyuff2095]

@@DSmartLife LithiumSolar is not an electrical engineer.

[@andycanfixit]

LTO chemistry is the better choice for a starting battery to replace lead acid. It can operate well below freezing, has excellent high C rate discharge ability, pretty decent high temp, and with 6 in series, 14.8 volt charging will keep it well under it's max cell voltage, but also well above it's minimum. They aren't as energy dense as lifepo4 cells are, but still much better than lead. Toshiba makes cells specifically for this sort of purpose, many larger generators use them now. They handle being run flat much better too.

[@smccomas01]

Thank you I often wondered about this taught me a few things and probably saved me from a mistake

[@NaughtyGoatFarm]

I have an electric car which has a lead acid battery to run the low voltage electrical system and it also powers the high voltage relay to engage the high voltage lithium drive battery. The 12v lead acid battery is a weak point in the system in my opinion. I would like to know if the lead acid battery can be replaced by a lifepo4 battery in my circumstance.

[@h8GW]

I'm pretty sure these LiFePO4 batteries are actually more ideal for the 12V circuit on electric cars due to not needing large cranking amps and getting recharged by some dumb alternator. SLA batteries, meanwhile, actually last longer in ICE cars because they need a large starting current regularly to break up deposits on the lead plates.

[@KokoReko2]

Was wandering myself for my electric car, no extreme temperature under the bonnet, and it should wight much less.

[@danielneikirk5085]

Thank you so much! I've been looking for a teardown on one of these older battery tender LFP batteries to see about adding a BMS to it. This @ 7:08 is the only one I have found on the internet!

[@ronaldoquintos1675]

I actually made LiFePO4 battery for my Prius and so far it is doing great after 5 years. They may be better suited for hybrid or electric cars since HEV and EV do not have alternator to charge the 12 Volta auxiliary battery.

[@cornelstamate2537]

this video deserves the highest ratio of likes to views

[@wobby1516]

Interesting to note that Tesla are now fitting in their model S plad a lithium starter battery. Of course it’s a lot different to an ice car as there’s no alternator or starter motor to worry about.

[@fastback777ray]

Very well explained..thanks for clearing a lot of doubts I had about lithium batteries and their limitations.

[@jeffmills2701]

Thank you for this very competent presentation. I was tasked, to design a multicell charger. In over my head, damn thing never worked, never figured out the FET balance or the tempature feedbacks, just given an AD design controller to use. I quit the field after this as it was for an EMP Paul Allen sponsored high burn very visible RD. Didnt go back. Just couldnt stomach wasting money like this as the company set me up team wise to sink or swim. There were no field notes on these controllers or the FETs that are design standard, like we had in my earlier stages as a designer..

[@wolfrig2000]

My truck is equipped with 4X 1000CCA batteries, it would take a lot of copper to get a 4000amp 14v source to the starter. My batteries are also located in a separate compartment away from the engine so they're more likely to be ambient temperature, freezing in the winter and 110 degrees in the summer but not affected by the drive train of the vehicle.

[@moestrei]

Most likely your starter motor is 24V and the batteries are 2s2p (2 in series and 2 of those in parallel).

[@sqttube]

Good explanation about the BMS. But LFP can replace the starter battery easily without the BMS. I live in Houston and I have been using the same home-built LFP battery for more than 10 years without any problem. NO BMS. All I have is small bleeder circuit that begins to bleed when a cell reaches 3.60V.

[@LithiumSolar]

Removing the BMS solves many of the problems, yes. This video is specific to people whom seem to think you can grab the $250 100Ah special w/ uber-cheap BMS and use it to start their cars.

[@sqttube]

@@LithiumSolar Agreed. I just bought a cheap 12V, 100Ah battery off Ebay for my other car. I will bypass the built-in BMS and install the bleeder circuit.

[@SocialPerspective101]

Plz share details of bleeder circuit

[@logictheorist]

No, Maybe, and Yes. I've been researching this lately (this video is 2 years old). If you have gas engine powered car that uses a 12V lead acid battery to start the car, the LiFePO4 is not an option. It just does not work properly with an alternator (as this video implies). If you have a hybrid or an EV that only uses it's 12V to run accessories, then there are now a few conversion kits that allow a LiFePO4 to be used in place of their GEL cell 12V battery. That is car model specific though. The problem with adding the battery without the conversion kit is that the LiFePO4 battery will never fully charge up using it's 14.4 volt max charging voltage. In other words the battery will only charge up to about 30% before the car's battery charging circuit shuts off thinking the battery is fully charged. Of course all that is needed for this to work is a battery with a BMS that feeds back the proper information to the cars charging circuit. But that has not been invented yet. Never say never, someone will figure this out and kill the lead acid battery industry someday. It's just a matter of time and pollution wise, we will all be a lot better off.

[@rickdevous9255]

Thank you for this excellent video. You have covered a lot of general information, and I found it very useful. I appreciate the explanation of the BMS and what it is designed to do, and on how some of the manufacturers bypass the BMS. I have been considering building my own portable vehicle jump start box using a LiFePO4 battery. I am primarily trying to get away from the weight of the lead acid battery. It has been difficult to come up with a LiFePO4 battery, that also has enough power to start a small block V-8, without breaking the bank. All I have discovered many of the things that you have explained in your video. I wish that I saw your video first. It appears there is a new classification of LiFePO4 batteries that they call “dual-purpose”. These batteries have the CCA rating, and are marketed for automotive use. WEIZE makes a 12V 60AH Dual Purpose LiFePO4 Lithium Battery, 800CCA, they call a Starting Battery Plus Deep Cycle Performance, Built-in Smart BMS, for Automotive use. The battery cost $250 so I will have to consider this purchase. Thanks again for the great information.

[@sswwooppee]

Thanks for the quick answer to my question. Very much appreciated.

[@BatteryOnBoard]

This is a great overview, but how do Lithium chemistry batteries work on Electric vehicles? EVs don't have a heavy start up load, so they don't need cold cranking amps. The battery draw is pretty consistent I think, except when all the accessories are in full play.

[@LithiumSolar]

No clue. All of my vehicles have engines and will have engines for the foreseeable future.

[@BatteryOnBoard]

hm...thanks? Odd answer for a handle like LithiumSolar, but hey.... I should think you would be curious as to how the different load profiles apply to this particular use case. Let me know if you post one about this use case and I'll maybe subscribe. @@LithiumSolar

[@LithiumSolar]

@@BatteryOnBoard The handle is "Lithium Solar" not "Lithium Electric Vehicles". I don't want anything to do with them quite honestly.

[@ovalwingnut]

LIke my grandma yells in church and my stepdad says down at the mill... "BINGO! You Nailed this" Being able to "take a peek" in those batteries was EYE OPENING. I had no idea (mark time). I haven't been this impressed since I stepped out of the shower dripping wet. Just saying A very sub-worthy video. Thank you. Cheers from So.Ca.USA 3rd house on the left. p.s. To someone who states "they've never had a issue" I would simply say that is what most "drunk drivers" probably say too... Yet we know it's not advisable.

[@lmychajluk]

Don't know about a car, but I've been using a Antigravity battery in my motorcycle for a few years. It's got a nice feature that if it drops in voltage to a certain point, it 'disconnects' itself. You have to push a button on the battery to reset it / turn it back on, and it will usually have enough juice to start the bike. Great for storing the bike. The only problem is that it resets the dash clock...

[@ericseidel4940]

I'm using LiFePo4 batteries for starters for 10 years now (first A123 purchased in 2006 for RC models)). At the begining only for motorcycles (park in a garage and no overheating concerns). They are still whithout any protection only a balance connector, and recharged/rebalanced once a year with a RC charger. Then I went for A 60Ah pack in a sport car that is park for long periods, in this car the battery is in a closed box in the engine bay, I just added some vent with a downpipe to the front of the car and upper holes. The box is now naturaly vented as soon as the car runs. NO ISSUES at all, I can say these batteries can handle tons of abuse and even my 15 years old A123 are still running. Another concern is that EOM charge regulators are sometimes tupping more than 14.2V at high rpm. I'm just starting to add built-in balancers as I found some 2A balancers that are not drawing current all the time (My first criteria is that the battery should NOT discharge itself). I also tested some latching relays that are doing great with big starter motors (with diodes/capacitors to release spikes), my plan is to replace transistors in a BMS by a latching relay that will disconnect in case of low charging state. WHY NONE of the BMS manufacturers are producing such latching BMS ?

[@DavidHalko]

Some bms’s do use relays. Relays can suffer from arc’ing and weld contacts closed, resulting in possible catastrophic failure. I agree, there is a lot of room for improvement with these topics of BMS’s.

[@SocialPerspective101]

Can you provide a circuit with components?

[@funfun5656]

If you want to avoid voltage spikes just run an inline capacitor (often used on cars running upgraded audio systems). These can be had for around $50-$100 and last a decade or more and will prevent the BMS on lithium battery pack from being too aggressive on the car's electrical system. It's also a good idea to have in general as spikes can happen out of nowhere from something as simple as a dying alternator/voltage regulator. The other thing you'll want to do is replace or upgrade the grounding straps throughout your engine bay and various points throughout your vehicle. This is important in general on aging vehicles but particularly crucial should you decide to run a LiFePO4 or any other lithium battery with similar output capabilities. The reason you'd even want to run these batteries can vary but I personally do it for weight reduction reasons. This battery setup can inexpensively save you around 40lbs compared to OEM BMW batteries which is significant compared to other weight reduction mods which often also compromise some other aspect of the car.

[@fredio54]

Simple, take some headway 38120hp cells designed for high current drain, put enough of them together to get the CCAs you need (under 2 litres 4 cells 325CCA, over 2 litres 8 cells 650CCA, bigger diesels 16 cells 1300CCA, etc), add a tiny inexpensive active capacitor balance board, unbridge the solder enable jumper and attach a tiny low current relay to that and trigger it from your start/run circuit so it's on when the engine is running and boom, reliable LiFePO4 setup in a car. 100AH is insane in a car unless you want to store it for 12 months without isolating it. I have 20 cars, 10 in use, 9 on LiFePO4 and of those 2 on 4 cells the rest on 8 and one boat on 16 cells (8.3 cummins). IE, I have 8AH on 2 cars, and 16AH on 8 cars and 32AH on the boat - why is this okay? Your battery ONLY has to run the starter motor, your alternator runs everything else. You need fresh belts for this as the charging is aggressive thanks to the low internal resistance. Correct that those precanned batteries don't work for it due to the electronics. And correct that you must be sure not to over voltage or under voltage your pack if you don't have a BMS, but reality is alternators are reliable and stable in voltage output and if you isolate or use frequently or match the capacity to the drain/time requirements you have, it's fine. I've been doing this for over 2 years now.

[@Bungaloo]

What about Hybrid cars that do not have an alternator or starter motor?

[@LithiumSolar]

I don't have a clue about hybrid cars. This video is in reference to cars with standard internal combustion engines.

[@Bungaloo]

ok we are talking about the 12 volt battery that's one thing first yes you can replace it with a lithium phosphate battery but I would definitely not use lithium ion battery. The good thing is that the new hybrids have a DC to DC converter where they can control the voltage between low and high low meaning 12 volts and a high of 13.8 this makes it perfect for charging lithium phosphate battery. And that will have a big massive improvement. But as everything there is a cost to this it's not cheap it is expensive. They are available. And we can also improve on the High Voltage section with super capacitors which last hell amount of years 20 to 30. Again it's all about cost and how much are the manufacturers willing to do and then there's also the safety involvement as well strict BMS control. Here's one picture of a simple example of a lithium phosphate battery.

[@kennethalmond8922]

Fantastic youtube - most intelligent discussion on this topic!! Thank you sir.

[@h.cavidarabac3852]

What do you think about prius's. 12v batteries of them are for peripherals and for the relays of hybrid battery. They do not have a regular alternator, one of the motors starts the engine and it is connected to hybrid battery. The 12v battery is in the trunk, so heat is not an issue.

[@moestrei]

Due to their very low internal resistance they can overheat your alternator too.

[@veganpotterthevegan]

I know someone that's been using one in his daily driver for 4 years...he drives over 20k miles a year. It was the cheapest battery he could find...no special BMS and we live in Salt Lake City...so hot summers and fairly cold winters

[@Leftplayer1]

Great video. I’ve been wondering about this for years. I did put one of those small 12V LiFePO4 packs in my ATV and it gave me nothing but trouble. As you said, it would randomly disconnect causing the ATV to just turn off, or it randomly just didn’t supply power (0v at the terminal) only to appear again as soon as I put a charger to it… Went back to lead acid very quickly.. On the other hand, I had a boat with separate starting and house batteries (both 12v) and it had a combine switch to allow staring the engine with the house battery in an emergency. I replaced the factory 54ah house AGM battery with a 100ah LiFePO4 battery and it was night and day. I could run fridge, stereo, pumps all day and night and it still had charge…. I never needed to combine but I did test it when I installed it (with a working charged starter AGM battery). I checked what’s going on with a clamp meter and it looks like the slightly higher voltage LiFePO4 battery was charging the AGM battery until they equalised. When cranking, the load is shared between the two batteries so the LiFePO4 wasn’t being overloaded. Once the engine was running, turning off the combine switch split the two so the alternator was now charging just the starter battery.

[@nikolatesla5553]

The battery in lots of vehicles aren't in the engine bay. They are sometimes in the trunk of the car or in the case of my van under the Driver's seat.

[@LithiumSolar]

I've never seen a "standard" car or truck (internal combustion engine type) with a battery in the trunk or under the seat. Which model/year van do you have?

[@brettmueller7288]

@@LithiumSolar My 2014 Dodge Durango's battery is located under the passenger front seat.

[@AveRage_Joe]

Excellent Video!!!

[@OffGridAussiePrepper]

is this a scam AJ i got one too, i dont do whatsapp anyway or any other social media

[@AveRage_Joe]

@@OffGridAussiePrepper 100% scam! I keep getting msg from random people!!

[@LithiumSolar]

It's a scam. This is the second time a fake account has done that - dozens of comments I have to manually find/delete. The KZbin spam filter is useless. It blocks so much stuff that is not spam, but it lets the actual spam through...

[@LithiumSolar]

Oh, and thanks for watching @AveRage Joe ;)

[@OffGridAussiePrepper]

@@LithiumSolar well u never mentioned anything about a prize and i dont go for that sort of thing anyway cos i live downunder, postage sux balls from usa.

[@lkeil84]

I wanted to replace my lead with Lithium on my yacht. I started with 4x138 amp batteries that were rated 150 amp continuous and 300 amp for 30 seconds. My first attempt I did not pay much attension to balancing the battery cable lengths and they would shut down during starting. I went back in and made sure all 4 batteries had equal size cables to a buss bar and solved that problem and it would start the Starboard engine with no problem, even better than the 3x750 CCA batteries I had on the Port Engine. Not being satisfied with the kw hours of those lithium batteries, I added a couple more to the Starboard engine (also the house batteries) and all was great. Still not satisfied with my inverter run time for the air conditioner, I went ahead and combined both engine battery systems together and put in 12 of these batteries. This gives me 1800 cranking amps of continuous power and 20kw to run my air conditioner (and all the cooking appliances, TV, etc.) from a 4000 watt UPS. I also had to change the voltage regulators in my alternators to 14. 0 volt maximum with thermal management as well. Luckily these regulators were $10 to put into my existing 140 amp alternators. Along with this is a 125 amps of solar charge controllers from 2kw of solar. I do not see that any of these batteries will shut down really for any reason being 12 in parallel. I also set my solar charge controllers to a maximum of 14. 0 volts and always monitor what is going on. I also have a 60 amp on board charger, but spend very little time at dock, and even when I do, I only turn it on a few hours before I depart. All that being said, I don't think I would put one of these in a car. I put one in my electric car and my tractor though, the electric having 14. 1 volt regulation with no heat or high loads and the tractor just being a real simple machine with no electronics. They have worked great in all these instances so far.

[@ubacow7109]

arent there a lot of race cars w/ lightweight Lithium 12v batteries? Braille & Antigravity have been selling lithium race batteries for a long time and Dakota Lithium uses LTO batteries for automotive as well.

[@LithiumSolar]

Probably. If the vehicle and battery are designed for it then sure. But dropping an SOK in a car designed for a lead acid battery --- no

[@wolfrig2000]

I've removed the battery while running many times in older vehicles, never had to do it in any newer vehicles, newest car I've done it to was 2000 Ford Focus and all of the vehicles have been fine.

[@michaelw4258]

Lucky man. The described phenomenon called "load dump test" . Usually control components of a car are tested, but 100% safe is this not. Voltages of about 150V.. 250V and low impedance of less than 2 Ohms are a bad combination for 12V devices.

[@TeVolt805]

@@michaelw4258 Exactly. Research "Load Dump". If you've gotten away with this it may be because the alternator wasn't charging at the time. Worst case is "alternator running at 60A into headlights, heaters and a flat battery and THEN you disconnect the battery". As well, all electronic parts in a car are TESTED to withstand a "Standard Load Dump Voltage Curve". But usually only once. They may not survive a second one. As well, people will tell you "it survived the standard test, but failed a real load dump in a car", because they can be worse than the "standard" one, which has to be generated by affordable bench-top test gear.

[@ACommenterOnYouTube]

I purchased an XS power agm battery for my Toyota as its main battery. It cranks the engine just fine, but if i drive somewhere and park it, come back, it cranks slow. Drive it home, let the car sit for 5 days, its practically dead. There is no parasitic draw on the battery. Even though its not LifePO battery, maybe its not a suitable replacement for a cars main battery. These batteries were made for car stereo competition batteries.

[@EspHack]

in my case I didn't solve anything, I just placed the LFP battery in the trunk and wired it in parallel to the lead-acid, along with a reset switch for the BMS in case it tripped, nothing yet, the voltage drop leading to it is big enough to avoid overvoltage while charging, so essentially the car is working same as usual but now it can power accessories for a whole day and the lead battery could be dead and I wouldn't notice if I were to get rid of the lead acid, I would just build my own LFP with raw cells + active balancer, LFP wont just blow up with overcharging like Li-ion would, it'll just degrade faster, so maybe it lasts 10 years instead of 20, and freezing cold isnt a thing here, I've got a bunch of computer UPSs on raw LFP that so far have outlasted brand new lead acid units twice over even though one of them keeps the cells at 3.8v

[@mikesmultimedia]

So, what is the best setup to use the alternator to charge the lithium solar bank, but, to prevent back drain from the 12v LED Acid car battery drawing from the solar bank when engine is off?

[@TheJensss]

New electric cars tend to ship with LiFePO4 12V batteries these days.

[@bujin5455]

Interesting. Glad you put it together.

[@bobjackson4720]

My ride on mower battery has failed. I have a starter battery which is said to be rated for six cylinder use. Can I use this occasionally with my mower without harming it?

[@LithiumSolar]

I wouldn't use one of these on a mower either for the reasons mentioned; however, there are a number of LFP "sport" batteries out there for such applications, including up to motorcycle use. Those would be perfect for a riding mower!

[@bulelanibaqwa]

What about using it as a the auxiliary or support battery in cars with start/stop - using the motorcycle starter batteries

[@hogfish3881]

What if you run parallel, small lead acid with lithium? In theory that should work.

[@EthanBecker-gq8ni]

It works with small issues. The self-discharge rate of SLA battery is 10 to 15% per month. LFP is with 3%. If you set the batteries in parallel without charge, LFP will charge SLA until fade together. Basically, the standard voltage of 4S LFP is higher than that of SLA 6S. If it runs in an ordinary charging environment, the SLA battery will be on a consistently high voltage by LFP and minor impact on health.

[@Shullalliance]

Hi thanks for the information. From what you’ve said the bus and temperature are the main issues. With that let me ask your opinion on LTO Cells which have a much broader range of low and high temperature charge / discharge capability. With no BMS and a balancer do you think that they would be a more viable alternative to lifepo?

[@Shullalliance]

(Typo: not Bus. BMS.)

[@DanaLeeGibson]

A NOCO GB150 Lithium Jump box started my 7.3 PowerStroke Diesel when both the vans's batteries were dead. And I can recharge the GB150 using the 12v power plug on my dash. It seems like a small step to make this all work without the lead acid battery. Maybe keep one small lead acid battery for when the van is running and the Lithium just starts the engine?

[@johngilbraitti9081]

I have a lithium iron battery attached by a dc to dc battery charger. Through this I charge a lithium iron battery which I then use for rv. Battery is far from heat source. Battery is not used for starting purposes.

[@LithiumSolar]

Sounds like a perfect installation then :)

[@Kosmonooit]

I'm working on some supercaps in parallel with the SLA battery and a controller to manage them, to increase longevity, I seem to go through a lot batterers in my diesel pickup, since its cranked many times per day.

[@jimyew9596]

Thanks for making this video. Very informative and well made.

[@JimmyLLL]

I was just thinking that when you shut your car off the battery is generally 100% full. To start the car you might pull 300 amps for 3 seconds which is 0.08ah so the battery is still 100% full and thus very little charging would take place.

[@SocialPerspective101]

For smaller cars it would be .03ah !

[@ToolsOutsideTheBox]

If you pair the lithium battery with a supercap/UltraCap then it’s fine. In this configuration the supercap handles the starting and fluctuations. The lithium battery acts more like a deep cycle. Most people doing this will usually relocate the battery anyway.

[@SocialPerspective101]

Can you provide a circuit diagram?

[@sdmoparmaninsd6713]

Also, most automotive equipment is actually extremely robust... most of the ECUs can handle things like coil packs arcing to control side, injector circuits etc without damage. Similarly, a loose battery cable is another situation that can be common, I've seen it many times and have never seen a damaged ECU...

[@BrandEver117]

What about for EVs, where they are only used to open/close the main battery contactors and to run accessories?

[@djsmiley01]

Fully agree. There are some exceptions. Some do offer LFP cells for starting purposes. With a moderate climate where freezing isn't occuring at extreme cold, LFP still might be an option. But as you said, with the proper cells. I have seen some vendors providing cells for both leisure and starting. But those used Winston cells, and multiple of them in a 2P4S config, to fit in a Ducato(Promaster) battery compartment, so that both provides sufficient capacity, and more starting amps (Winstons are rated at 3C). Also, they allow charging up to -20 celcius, and the LiFeYPO does allow slightly higer voltages (3.85V/cell) But my personal view? Too expensive. Just stick with lead-acid for starting.

[@bentleyjarrard885]

djsmiley01, Yes there are indeed some LFP automotive starting options. Everything you stated is true, with the possible exception of the price issue. I posted a comment about that up above if you are interested.

[@lowvo]

I've been a mechanic for over 20 years. Not one single time have I damaged any component by disconnecting the battery while the car was running. I regularly use this method as checking an alternator. Not saying it never never happens. But it's never happened to me, therefore I continue on with my methods.

[@Jasonoid]

QUESTION: so when do you start to see damage from low temp charging a Lifepo4 battery? I have purposely kept a 100ah lifepo4 in the freezer for 48 hours, then instantly charged it up at 15 amps. I then did a capacity test and it didn't lose any capacity. This battery obviously doesn't have low charging protection.... But does it need it? I still pulled over 100ah. I'm just curious how many times it needs to be charged below freezing before you see damage. It has to be more than 3 since I have done that process (freeze, charge, test capacity) and it still pulls 100ah....weird right?

[@LithiumSolar]

That's a very good question... Perhaps something I can do long-term testing of somehow.

[@Jasonoid]

@@LithiumSolar sounds good! I've always heard "charge lifepo4 below 32f and it's permanently damaged". My 100ah still works great after 3 charges below 5f. I'm sure you have plenty of 'spare' batteries to test this on and your audience would benefit from the testing.

[@Acamperfull]

Charging at low temperatures with a relatively low current like you did (0.15C) should be no problem even with LiFePo4 cells that are not suitable for higher charge currents (>0.5C) at low temperatures. As the battery probably already heats up a little from the discharge current when starting the engine I think the risc of damaging the cells by the alternator recharging it is not that big. But ideally the alternator voltage and thus charging current should be lower as long as the battery is too cold or you should use LiFePo4 cells suitable for low temperature charging if you use them in a cold climate.

[@JeremyAkersInAustin]

Damage from charging a below freezing cell is instant and permanent. The "damage" is caused by Lithium plating so this is an instant and irreversible damage. If you did a capacity test and still pulled 100 AH then there was no damage. The tricky thing with cold charging LFP is that there's no magic number at which an LFP cell will be damaged by cold charging. Every cell will be different. So 15 amps on your 100 AH cell may have not been an issue at all. 15 amps into a 100 Ah battery is only 0.15 C after all. But if you did the same thing with a 15 AH cell the result may have been much different because that would be a C rate of 1.0. You *CAN* charge LFP below freezing. But how fast you can charge varies from cell to cell based on how easy the Lithium Ions can intercalate into the anode. Cells that have higher C rates for discharge will generally also have higher C rates for charging because the intercalting process is easier. These same cells with a higher C rate for charge/discharge can also be charged faster at sub freezing temperatures than other LFP cells with lower C rates. Basically LFP cells don't really "freeze". They just get cold. It just so happens that the temperature where most LFP cells can no longer accept normal charge current is somewhere close to the freezing point of water. But for a cell with a lower C rate you might need to back off charging current at around 40-45 F, or for a cell with a very high C rate you might not have to back off until you get below 0 F. The whole "don't charge below freezing" is just a rule of thumb. Most LFP cells start to show damage from high charge rates somewhere around 32 F, give or take. So to be safe we generally just avoid charging at all below that temp because unless you have a data sheet that specifies exactly what current you can charge at below 32 F, it's just not typically worth risking your expensive cells.

[@fritzkabeano1969]

I bought a $15 aquarium heating pad for my SOK to solve the cold weather charging problem. I've got my battery in a small cooler for added insulation. Problem solved.

[@hassansyed5661]

What about using 12V Lithium Iron battery for home use with UPS?

[@Ebiczebulanious]

What if you put an inverter on the car battery and use the ac output to charge the LiFeO4 in a trailer or camper?

[@alozborne]

Would be interested to know your thoughts on using a LiFePO4 12V battery as a starter battery for an EV (2013 Nissan Leaf). Other than the cold temp charging concerns, the 12V battery only needs to supply enough power to close the contactors, along with some overhead. For the Nissan LEAF, that's about 250W. The DC-DC converter's output voltage may be too high, it's hard to find good specs on that. Having said that, the DC-DC converter in a LEAF is notorious for under charging the 12V stock lead acid battery.

[@mkmd8959]

Prius battery also no alternator, 12v battery is powered by high voltage battery

[@mrcleanisin]

If LiFeP04 batteries must be charged less than 14.48 volts, how do modify the motorcycle regular to match.

[@redwood1957]

very informative. I have a 9.9 hp outboard motor on a sail boat that can start with a motorcycle/ lawn tractor lead acid battery or pull start.It puts out 14.5 volts at idle. the manufacture says it will charge a lead acid battery to power other loads on a boat. about 3 amps last check. Seams like for me using LIPO4 battery could open up a world of hurt for me in a failed battery case. Thank you

[@varman001]

The best place to keep the LiFePO4 pack is near the front bumper grill... not directly in front of the radiator but on the side... so it gets hit by cooler air when vehicle moves and away from the engine heat source. OR the best place would be under the TRUNK inside the vehicle! but make sure to use an adequate gauge of wires. a $50-100 pack will save a lot of money over years.

[@varman001]

Installing a LiFePO4 in conjunction with your existing lead-acid battery will eliminate any current surge... and regulate the voltage and will keep both batteries charged and warm in cold weather. This is the method that nobody mentions. No need to buy another battery for life! From my personal experience.

[@adairjanney7109]

what about using it as a backup battery in the trunk, that way it just keeps the lead acid charged and gets charged sometimes

[@dchungmanson]

Thank you for Excellent presentation . So many times we have been asked about the same question and our reply No No No .

[@jeffwatts2727]

I’ve seen capacitors linked with a little LFP

[@jamesstewart5005]

What about in electric cars that have a SLA battery just for things like car electronics? The use DC to DC converters for charging the 12v battery and don't need those cold cranking amps.

[@uhjyuff2095]

The SLA battery on an electric car is just a back up, because like you said the alternator/DC converter is actually handling the 12v loads.

[@putteslaintxtbks5166]

Another big problem is with the low resistance of lifepo4 can over run the alternater and burn them out by drawing more amps then they're made to put out.

[@uhjyuff2095]

Cars should come with smart alternators that don't burn themselves out. Who is designing these alternators?

[@Josh-b3c]

@@uhjyuff2095 some do but smart to them means they turn off while you were driving in an effort to save fuel of course then the alternator has to make up that power later on so I don't really see how that would save

[@uhjyuff2095]

@@Josh-b3c I think it saves because lead acid is not efficient when accepting a charge and most of the energy is wasted, so instead of having the alternator charging and charging even though the battery is 100 percent full and just wasting energy, it will go into a low power mode so then you gain that 0.1mpg back.

[@putteslaintxtbks5166]

Victron has videos on you tube, were they tested alternaters hooked up to lifepo4 batteries.

[@scotwilliamson1095]

Incorrect. A 100 amp alt can put out 100 amps. No matter if those amps are going to lead or lithium. generally with lead acid there is no limit as to what the battery can be charged at, but lithium has a controller that limits the input and output amps. So it actually the exact opposite of what most think.

[@keepingup2952]

It's easy. You just need to brush a little Dodo bird oil onto your battery terminals before installation. It helps stop all the freezing problems and evens out the voltage. Amazon's all out right now, so just be a little patient.

[@LithiumSolar]

LOL!

[@danya822]

Older video, but hopefully still interest in this as I see places like walmart and home depot selling lifepo4 starting batteries (for small engine applications) for about the same price as lead acid replacements. If lack of BMS and constant charging while running damage the lifepo4 battery (as I understand it, and shown in this video) is there still a longevity benefit to throwing a lifepo4 battery in a mower? Most have the same issue it seems, SLAs are pretty poor quality anymore and you might get two seasons out of a replacement. A lifepo4 that lasts even three years, at current cost, would save money. It doesnt help that the pages for the batteries seem to indicate you need a lifepo4 charger. Well, with a generator like on the riders, you dont get a choice. It charges via the generator when riding.

[@ladjkaoz]

Great info. So the most or biggest pr9blem would be charge on cold weather, Lucky i live in south CA temps here dont get below 0° how ever, am other problem i see is the BMS disconnecting the or stop charging, this may burn your alternator, or throw a malfuntion code on the dash board especialy with newer cars... 😔

[@moviebestmusic2806]

headway made the 8Ah battery cells rated for 30c continual discharge,but still temperature is a problem if you want them in your car engine bay

[@offgridwanabe]

All true even EV's with 60 -70 kwh still use a lead acid battery for the 12 volt system. Some things are just easier that way. I did like the one you tested that used the alternator to heat the battery which shows some advanced thinking

[@897aa33]

They only agree to use to keep who ever owns led acid tech happy. Otherwise led acid would exit and die.