Charging Lithium Batteries With Alternator - Howto Guide

[@doraexplora9046]

Key take away's are: Lithium has much lower internal resistance, so alt. produces much higher current, which could/can/does damage lithium batteries not designed for such high charge rates. Use a descent size cable. Make sure the batt. charge system is 'selectable' or switchable and not constantly connected. Lastly, if you're a Dutchman, learn to speak English as well as this guy! Awesome!

[@cleversolarpower]

Actually the batteries can take it, it's the alternator that is not able to deliver high current for long times without overheating. Thanks for the compliment, I try my best 😁

[@doraexplora9046]

@@cleversolarpower The higher the rate of charge the more expensive the battery. High charge and discharge rates in a LIFPO4 design is THE most expensive format you can get. But for camping. A slow discharge is usually what you want. So I have a 20AH LiPO batt that can only take 5A charge rate. It takes it in slow and lets is our slow. I think I paid USD10 for it. I have four of them connected with a BMS for a total of around USD$45 at 80AH, charging at 20Amps. This runs my fridge, phones, lights etc. for about a week.

[@guywilliam6065]

@@doraexplora9046 That's a great price. Were did you buy them? Any 20 AH LiPO battery I've seen run around $100 each.

[@markoshun]

Excellent videos. Some of the best on any subject, especially considering how complicated this is. Clear, concise. Thank you.

[@cleversolarpower]

Glad it was helpful!

[@tomede472]

Thanks always very interesting and professional explanation about electronics.

[@MrDave9111]

In many cases you don't need a DC to DC charger to add one or more lithium batteries to a vehicle that has a traditional lead acid starting battery and alternator. There are various ways to do it. Victron sells a number of diode isolators. But to use them effectively you need to cut into your alternators field circuit. The better way is to use a smart voltage sensitive relay. There are several available. You need to check to make sure your alternator can output at least 14.0 volts when running. 14.4 to 14.5 is ideal. That is easy to determine with a fully charged lead acid battery, start the car and check and see if the charging voltage reaches at least 14 volts and no more than about 14.8 volts. You also want to make sure that your alternator has enough capacity to charge the Lifepo4 battery. A discharged 100ah Lifepo4 battery can draw up to 35 amps at 14.5 volts. If you have enough extra alternator capacity, the addition of a voltage sensitive relay with an ignition interlock is the hot ticket. If you have a large alternator, 100+ amps, you may be able to charge two or more 100ah, 12 volt Lifepo4 batteries in parallel or one 200 ah, 12 volt battery. You can buy a DC to DC converter, but if you want to charge 200 ah worth of batteries quickly, you will need a very expensive device. A voltage sensitive relay can do the same thing for less than $100. In any case your alternator capacity may be an issue. What ever you do, put a fuse on the positive terminal of your Lifepo4 battery/s. A MRBF fuse is about $15 on Amazon with a holder. Cheap insurance. Also make sure to put a fuse or breaker on the feed from your 12 volt lead acid battery to the relay isolator. The reason for the isolator is that lead acid batteries operate at a slightly lower voltage than Lifepo4 batteries. If you just parallel the batteries, the Lifepo4 battery will discharge into the Lead Acid battery when the vehicle is not running. To do this right, using an isolator, relay or diode, you are going to need a good digital multimeter and a clamp on DC ammeter. If you don't have those items I would recommend using a DC to DC converter, but they aren't cheap either. I'm seeing $200-300 for a 60 amp unit. A 150 amp relay isolator that I have used a few times now is about $60.

[@CowsGoMonkey]

What relay isolator(s) would you recommend for a 130A alternator? I also was looking at a 200A "smart" solenoid isolator from genesis offroad, $100 on FB. Would that also work with a different starter/aux battery, assuming the charging voltage is tuned properly?

[@doraexplora9046]

You forgot the part where you rip out the alternators internal regulator and install an external regulator which you control from the dash. Xantrax comes to mind.

[@The_Ballo]

I have a 200A alternator that outputs 14.2V when driving. A method to avoid DC DC charger would be nice as they charge at much lower amps and are expensive. My 60A MPPT solar controller is more powerful and cheaper. I'm sticking with AGM until I can figure this out

[@The_Ballo]

Everything is currently wired with 000 gauge. Currently using a 500A isolating relay between the starter AGM (high amp) and house AGM (deep cycle)

[@brucew4726]

I'm charging my 105amp Lithium phosphate battery with a Sterling BB1260 on the 30amp reduced power setting. My Peugeot Boxer van will charge the battery at around 25 amps until the battery reaches around 75% charged and then the charge voltage drops to about 10 amps and then 8 amps. I'm using 110 amp cable from the starter battery.

[@TheJR914]

All those comments make sense. I am using lithium batteries for my truck (diesel) and cars as the only dc source. All of my batteries are DIY built using smart BMS’S on all of them. I can program the amount of charging current both input and output on the BMS’S and I have never had a problem with the alternators. All alternator has a regulated output the voltage can only go but so high no matter what rpm it is turning 750 to 7000 rpm. I also run lithium on my motorcycles with the same concept no problems for many years.

[@cleversolarpower]

Thanks for sharing your system. How do you size the current limit of the BMS? 50% of the alternators rated current?

[@TheJR914]

My BMS’S DEFAULT IS 110AMPS . This can be change to anything lower its label over current in the settings BMS. Any alternator that’s has a built in regulator will limit the current draw to a load when it reaches its saturation point. Any load is determined by its resistance or inductive load. The BMS uses this same concept in limiting the current to itself.

[@_JB89]

I think you might be the only person doing exactly what I've been trying to do. I have a 7.3 and replaced the two starter batteries with two LiFePO4. Only problem is its killed 2 alternators already and my local diesel mechanic isnt accustomed to lithium so he doesnt know what to do. You think if I get one of these BMS' it would solve my issues?

[@TheJR914]

@@_JB89 I can not understand your alternator burning up. The alternator has a built-in regulator how can it burn it self up. Plus you have loads on your alternator injectors, fuel pumps and the ECU. If you disconnect the battery from your alternator you should measure the voltage output of the alternator. It might go to about 15 to 16 volts. If it goes to about 18v your regulator may not be working. I have Lifepo4 in six of my vehicles and all working okay. The only thing you have to be careful is the engine heat.

[@_JB89]

Trust me Im as confused as you. Im not sure if they've "burned up" but they definitely stopped working entirely. And these are made to be direct drop in replacements, according to the manufacturer Dakota Lithium. The most recent one was 240 amp alternator, well within the 270 amp hour limit of my 2 batteries in parallel. So thats why im searching for answers.

[@TheBioniXman]

Not sure that I understand this as on many motorcycles there aftermarket Lithium batteries available to replace the standard battery using the same charging system. I ran one of these on my Ducati for 2 years with no problem. BMW and Ducati both offer a Lithium battery option with the standard motorcycle alternator charging system.

[@cleversolarpower]

That's weird. Maybe they have a smart alternator that limits the charge current?

[@andrewwhite986]

They have current draw resistors on the circuit board inside. Design to stop over charging and limit the current. Though these are usually very undersized.

[@tomaszwwysokinski9236]

Those are not deep cycle batteries as discussed here.

[@TheBioniXman]

@@tomaszwwysokinski9236 The title says LITHIUM batteries. There is no mention of any derivatives.

[@IntoTheMystery13]

Motorcycles have stators not alternators, and use different voltage regulators

[@michaelburke1023]

Redarc brand is another certainly worth mentioning

[@LintiNuci]

Salu Mulțumesc pentru explicație. Poti pune mai multe sutitrari sa inteleg mai bine! mulțumesc

[@robinhooper7702]

Hi, I love the way you teach. I'm learning a lot from this just one vid, thus far. Thank You. My application is to charge my Lithium Ion batteries(6), wired in series, 12V at 10amps(?) each, which is how my E-bike was assembled, by the supplier. I have retrofitted an alternator that its' rated output is at 12V-145amps. The original setup had my E-bike last only 1-1/2 summer seasons. Very poor for a 3K purchase. At 8:10 you mentioned that I would need a Lead Acid battery to do what I'm planning, Yes? As well as a DC to DC converter. I have, as a gift got a LiFePo4 battery(1). Can I use this Battery instead of a Lead acid one? Since my existing Lithium battery bank is toast, I would much rather use LiFePo4s. Will I still need a Lead acid battery connected straight from the alternator? As far as an isolated and non-isolated converter is concerned. How would I be able to tell if I have sensitive electronics in my e-bike? Since I will be replacing my Lithiums' Do You have a recommendation for a LiFePo4 supplier? Thanks again for sharing your knowledge in these vids.

[@cleversolarpower]

I'm afraid I don't understand your question. Have you fitted an alternator on an e-bike? If you have a small lifepo4 battery (100Ah or less), you might get away with connecting it to the alternator directly, since you have a 145A one. Add some voltage drop in the wires and test the current coming out of the alternator. Max should be 75A.

[@robinhooper7702]

@@cleversolarpower Hi, thanks for your reply. And, yes I fitted an alternator to my e-bike. I'm a cabinet maker so I'm not that versed with electronics. How would I add a voltage drop?

[@TheoSmith249]

@@robinhooper7702Install a resistor use ohms law to to determine value. Resistance is = to Voltage divided by current R=E/I

[@robinhooper7702]

@@TheoSmith249 Just so that you and I are on the same page. I have a source of 12-13.5 Volts at 145 amps. And I need 5 amps at 72 Volts to operate my ebike. So I would need a Buck Boost Converter to do that. Yes?

[@canyondan]

Excellent information

[@marcbloch1963]

The company „Battleborn“ is advertising on their website a battery isolation manager (BIM - made by Precision Circuits) specifically for lithium batteries which monitors voltage and connects batteries when needed. Under normal charging conditions, the BIM will connect for 15 minutes every 35 minutes. That means that the BIM will connect for 15 minutes, disconnect for 20 minutes, and repeat this cycle until the coach battery is charged. I was wondering if I could install this device in my van instead of a DC to DC charger. Your thoughts please.

[@Sylvan_dB]

Is 15 minutes under max load safe for your alternator? Is 20 minutes sufficient cooling time to prevent overheating? Does your alternator always put out the 14.2 to 14.6 volts needed to fully charge a LiFePO4 battery? Many newer vehicles drop the alternator output voltage to increase fuel economy. This started appearing on a few vehicles 20-ish years ago and if present on your vehicle it will take a very long time to reach full charge, if it ever does. I think the BIM is a hack solution to "I don't know how to connect a modern DC:DC charger" and will never be as good a charger as a DC:DC charger and it is probably not as safe for your alternator. It might be good enough.

[@robh2515]

GREAT info... straight to the point...and no stupid guitar intro.

[@VanVentures-oo7bm]

I'm doing research for my ambulance tiny home build and im pretty sure you solved a major problem of mine with this video. Here is my plan. My abulance has 2 alternators i beleave 120 amps each that normally charge 4 agm batteries as a 12volt system. 2 for starting and 2 for box accessories. I want to replace the 2 agm batteries for roughly 300AH 24v. I want a 24v for Air conditioning efficiency and limit amperage of the system in general. My problem was the alternator possibly overheating because of that shotty victron alternator video. I agree with your assessment about it. So i think the 12-24v sterling power dc to dc is perfect for what im doing! Thanks so much.

[@cleversolarpower]

I've heard the sterling power dc to dc charger is great (but expensive).

[@seancarwin8034]

Hey good day I would like for you to do a video and how to wire a shunt to a 12 volt battery

[@garymiller7870]

Nice overview, i can see how the DC-DC charger isolates and protects the LFP house batteries but how does this protect the alternator? I have a 120A alternator with a Balmar MC-614 regulator and an Orion XS 12/12-50A charger. At 2800 alt rpm, fast idle, the alternator puts out 65-70A, hot, but at idle,1600 rpm, the alt puts out 30 to 40A. As the charger draws 50A the alt quickly overheats at idle, triggering the temperature field limit. Where does the 10 to 20A come from, the starting battery? As the alt cools down the amperage ramps back up and the temp maxes out again. So if sitting in traffic the starting battery and alternator are suffering high temperatures and oscillating voltage etc. How is this prevented? It would seem the field voltage should be limited and or the alternator substantially oversized? How is the field voltage limit determined? Does this system really need a 200A alternator to supply a consistent 50A to the house batteries?

[@Energy_69]

Alternator is pretty much the generator, lower capacity alternator overworking with heavy load it’s obvious will get damaged in the long run ! If you want to run a lot of batteries, you need bigger alternator but you still need to consult with a specialist ti find out if this change will effect electrics into your vehicle from this high current

[@guywilliam6065]

A DC/DC charger is designed primarily to protect the alternator and vehicle's electrical system. With the Orion XS 12/12-50A Charger, you can limit the input and output current in the settings. I'd limit the amps to take load off your alternator until you find the sweet spot. Ideally you'd average around 50% of the rating for the alternator. The electrical systems on many modern vehicles stop/reduce charging under certain conditions (rpm, temp, voltage.....) for fuel economy. Basically the starter battery alone runs the vehicle for periods of time. When this happens, you may see a reduced input to your charger. To test this, drive around with one of those Bluetooth battery/charger monitors connected to your vehicle's battery.

[@garymiller7870]

I added a shunt to the AGM starting battery and found that at low RPM the engine battery discharged ~5A until the Orion input limit voltage was reached. There is a balance to be made between the Balmar Belt Limit setting, and Bulk/Abs/Float voltages vs the Orion input voltage limit.

[@ahyungrocks5509]

Thank you! You de-mystified the concept of charging LiPO batteries.

[@gregsnape9622]

Really good information, thank you.

[@sranjaniis]

Good info . Short and to the point videos . No complains .

[@cleversolarpower]

Glad you liked it!

[@brianbender3431]

Good video. Would it be possible to plug my Inverter into the cigarette lighter (auxiliary port) of my van, and then use my LiFePO charger to charge my battery while driving? Is there any way to use my car's cigarette lighter port...and if so what would be max amps I could pull w/out harming my car? Thanks!

[@cleversolarpower]

A cigarette lighter port only has a very small current. So not suitable for charging.

[@jacklabloom635]

Car manufacturers will eventually move to lithium batteries. When they do, the standard alternator design will be changed to a lithium suitable charger. Those lithium chargers can then be used to convert older automobiles to use a lithium battery.

[@cleversolarpower]

There are smart alternators which limit their charging current based on the temperature of the alternator. But they are available in new vehicles.

[@The_Ballo]

Doubt. Lead acid batteries are more resilient especially in cold weather

[@GaryRust-xj7yt]

I have 20A Renogy DC to DC charger. The installation is as per Renogy to my 12 volt 100A lithium battery. The system starts to operate and within 3-5 the cooling fan starts and within another 3 minutes the fuse trips. Any idea where I have a problem?

[@Sylvan_dB]

Which fuse? Input (from vehicle) side? If so, it sounds like you have too much voltage drop on the input side. Maybe your input wiring needs to be larger or your have a poor connection. (Too much voltage drop on the input will cause the DC:DC to draw more current in order to provide the same output charging power.)

[@user_abraham]

Hello, I was just wondering whether it would be possible to purchase this and drive the automobile alternator connected to a high-rpm, 220v AC motor. I have a 5kva MPPT inverter, but I don't want to use a solar panel. What do you think of it?

[@twistedtech361]

Hello, thanks for the video! The title was my hook. My RV has dual alternators one for the starter and one for the house bank (Dual lead acid) the first video I watched was "drop in LIthium is a lie" was good and lead me here. Question? what will happen if I swap one of the lead acid batteries with a lithium? My onboard charger can be modified to the higher lithium voltage, would I need to? I can not change the charging voltage of my isolated alternator (120amp) so I cant set it to lithium. Can you recommend one of your videos that would help me ease into lithium?

[@twistedtech361]

Wow, I just rewatched the video and my questions were answered. Adding a DC to DC controller would mean I can replace one of the lead acid batteries and disconnect it from the bank, add a DC to DC controller to charge the battery and not have to do any changes to my current setup!! It took a minute to sink in LOL

[@renepereiradasilvahe2039]

Awesome video, thanks for that! I'm building a camper van in Brazil and any DC:DC here is really expensive so I was wondering: what if I use a charge controller instead between the lead acid battery and the LiFePO4? I have a 100ah LiFePO4 and 60ah alternator so I would put a small charger controller (maybe 30ah) so I don't overcharge my alternator. Also, I would put a circuit breaker so switch on only after a few minutes after I have my engine running. Could that work?

[@cleversolarpower]

The input voltage of the charge controller should be 5V higher than the battery you are charging. So you have to use a DC to DC converter to increase the voltage before attaching it to a charge controller. Then only enable charging when you are driving because otherwise the starter battery will get drained.

[@renepereiradasilvahe2039]

@@cleversolarpower That makes sense! TSM, bro!

[@MikeCris]

I replaced the 12V house battery in my class C RV with an SOK 12V 206Ah LiFePO4 Battery. I currently have the cable used to charged the (now removed) lead acid battery disconnected until this alternator charging issue is solved. If I buy a Victron DC to DC charger (Orion XS?), can I simply use the alternator cable that previously charged the house battery as the input into the Orion XS...or do I have to run a cable from the chassis battery?

[@endurocrosser8834]

I have a 30A Dc-Dc Orion Victron Smart Isolated (no installed yet) and my van’s alternator is rated at 180Amp.Will that be ok? Can you tell me what type of fuse and how thick the wires must be?thanks a lot!

[@cleversolarpower]

Yes, perfect. I recommend watching my video about selecting fuse sizes, wire sizes and voltage drop.

[@halfaistos]

Very informative video! In my opinion, one of the best on KZbin on this subject.. definitively because of the drawing illustration! I just currently debate on BBC Forum "how to protect the alternator", actually, by presenting the video you mention; "How not to blow up your alternator when charging Lithium". You've mention on the video that they make the experiment to fail and you present facts to prove it. However this scenario on their video... precisely exist on my boat; Mercury 150hp has only 60Amp alternator in tight space, hot under the cowling and is forced to charge dual purpose 120Amp 1100 CCA battery. I'm going to use Victron DC/DC isolated charger 18Amp (the only info given to me by some reputable Utuber) Would you installed in this situation higher amperage charger like 30,40amp? What size of circuit breaker or fuse would you use? Could you - by using your magic pen -draw lines from alternator-fuse- dc/dc charger-battery please? Thank you!

[@cleversolarpower]

Thanks! In that case you should use a DC to DC charger. It depends on how quickly you want to charge your secondary battery. If it doesn't need to be charged quickly, then no need for a higher current. Please take a look at my video about selecting fuses and wires. For a 18A version, multiply by 1.25 to become a minimum fuse size of 22.5A. This doesn't exist, so choose one up, which is 30A midi fuse. Then select a wire that can handle at least 30A. This is an 8gauge welding cable.

[@yochemin]

Good video easy to follow, in the formula for how long to charge how does it change when running 2x100ah batteries the same in parallel?

[@ovalwingnut]

Thank you. Definitely a sub-worthy video.. Thumbs up! p.s. Limiting amperage by undersized wire? Wow.. and on purpose!

[@cleversolarpower]

Yes, but it's not what i would advice to do.

[@36northstar]

Hi, and thank you for the advice regarding the charging of my 100AH Lifepo4 battery from my car. my situation is slightly different. My battery will be installed in my small rv trailer being towed by my 2019 Toyota 4 runner. until now my rv battery was always a lead acid battery and charged from the car. It appears that I will have to modify this system now for my Lifepo4 battery? can you describe what I need to do?

[@f150bft]

I'm not looking to charge my lithium RV battery with my truck although the 7 pin connector has a charge line in it. What happens to my truck alternator as I'm pulling my camper down the road, will it be overworked? I only have the one battery in my RV.

[@marybrooks2458]

if the camper van has a second alternator to supply power to the lithium batteries, do you still need a DC to DC charger?

[@cleversolarpower]

If it's a normal alternator then yes. If it's a smart alternator with current limiting, then no.

[@patriot3636]

I have 12 XS Power Lithium cells. Each one is 2.3v at 40Ah. The way I put them together, makes one battery at 15.5vdc. Do these cells need to be charged the same way, or just straight off of the alternator. I use this bank to run only a CB radio and 1,000 watt amp.

[@dan32one44]

Good stuff 👍

[@cleversolarpower]

Thanks Dan!

[@Foil4life]

I’m using the dc charger to lithium battery to run my stereo off the lithium battery. Will the non isolated introduce noise into my amplifiers? Or is that not an issue? Thanks 😃

[@thriveforbest3217]

Yinglong Lithium cells Is that apply If in the car is just LTO cells and no other batteries.? Runs stock alternator in the car audio system is in there . So current drown is always here . Why do i need dc to dc charger in my situation? Can someone explain me please

[@cleversolarpower]

I explained in the video why you need one. It's because the battery has low internal resistance. Meaning that the current will be high (not limited). In a lead acid battery, the internal resistance of the battery is higher, thus the current won't be that high. I=U/R -> resistance higher means lower current.

[@SRTR_Channel]

Hello. Is it possible to connect 12c alternator with dc to dc charger to 2 unit serial connected 12c 100 amp battery?

[@cleversolarpower]

only if you have a 12v to 24v dc to dc charger. Victron has these.

[@garyjunker83]

Very professional and good information. Thoughts on a Precision Circuits LI battery isolation manager vs B2B??

[@kais7137]

Very interesting video, thank you! It makes me wonder if there is a solution for my problem; I'd appreciate any ideas. I have 2 Honda outboards, each with a 12A charging coil. I also have a 40Ah and a 100Ah LiFePo battery. Is there a way to use the batteries for starting the engines and to charge the batteries from the engines? I guess with the DC to DC charger, I could safely charge the batteries without damaging the coils (what would be the right charger here? 12A? does that exist at all?). But then, the current cannot go back to the engines when I want to start them, right? Or is there a solution? Many thanks in advance!

[@bobk3745]

I'm charging a 100 AH lifepo4 battery from either solar or the onboard (RV) converter. My battery charge line (pin #7 on the 7 pin connector) from my dual alternator GMC diesel truck is protected by a 30 amp fuse. Can you tell me how the alternators could be damaged by an over amp condition when the charged line is fused? Shouldn't that fuse blow before alternator damage? Thanks

[@eroenker]

I've seen a few videos of overlanders using an Orion 12/24 DC-DC converter to fast charge their power banks via MPPT input. Seems like a pretty good solution for 48v systems. Is that a good option?

[@cleversolarpower]

The input of the charge controller needs to be above the battery voltage. With a regular dc to dc converter, you risk draining the starter battery.

[@thriveforbest3217]

Is this apply to LTO cells as well?

[@cleversolarpower]

I don't have experience with LTO cells. It depends on their internal resistance.

[@jayscott1380]

Can you charge a 36v lithium battery using DC to DC charger coming from a 12v lead acid starter battery?

[@SpaceSoftSystem]

Good , Thanks for video can i use it for electric two wheeler 48v 6A lithium battery auto charging system , using wind turbine system on driving auto charging system by electric two wheeler

[@cleversolarpower]

Wind is not useful for residential. Better use solar power.

[@zaneenaz4962]

Charging with lower Currents extends your battery life. Under 0.2C has been often recommended. C =rated current of battery. Typical 100A alternators can deliver most of their power to the low internal resistance lithium batteries

[@drjasper100]

Excellent - one or the easy videos to understand.

[@TheCornucopiaProject-bd5jk]

You don’t need a switch for the renogy dcdc50. It senses the higher charging voltage on the starter battery to turn on and off. And with solar connected, alertât or charging is limited to 50% or 25 amps, solar would bring in up to an additional 25 amps.

[@cleversolarpower]

A switch is recommended if you are approaching a campground. Turning on the DC to DC charger while driving will consume more fuel. So turning it off is better at that moment.

[@chuckaeronut]

@@cleversolarpower Why is a campground specifically a factor which would incentivize you to turn off your alternator charging? There is very little (perhaps immeasurably little) additional noise generated by the extra load on the engine. Regardless, in my opinion, the amount of fuel consumed in order to charge the batteries is tiny, and not worth having to remember to use a switch. Approximately 800 watts (60 amps times 13.5 volts) going into the house batteries will place, at worst, maybe around 2,000 watts of extra load on the engine. Since your engine is already running because you're driving, you only pay for this extra load (it's not like you're running your entire engine only to charge your batteries). At 25% efficiency, this is equivalent to 8,000 watts of chemical energy coming from your fuel tank. For diesel, this would be just under 0.2 gph. For gasoline, a little over. So, driving around charging your batteries for a whole hour would cost about a dollar. That single dollar, especially compared to the cost of driving in the first place, is well spent on not having to remember to flip the switch back to "ON" so as to be sure the batteries are charged the next time they are needed. And of course, if the batteries are fully charged and draw no current, it doesnt't matter whether the switch is on anyway. So the extra draw is finite!

[@Tom-Travels]

Mein Gott! Das ist wonderbar!

[@cleversolarpower]

Glad you liked the video Tom!

[@claeslind9532]

I just bought the ecoflow alternator charger, still haven’t arrived though

[@cleversolarpower]

Seems to be a new product. I will await some reviews from people online.

[@42kwhaum2]

i have 90Amp alternator (Sailing boat) and 280AH Lifepo4. I charge directly from the internal regulator. No problem. I use 20mm2 wire, it 's hot but it's limit DC current in this configuration. I dont use BMS for protect diodes in regulator (running with battery swich off)

[@cleversolarpower]

Did you measure the current going through it?

[@tomywrobel6428]

What would u recomment i am building i am building 500ah battery lithium ion need to put in to semi truck for apu unit to run longer what will be best way to do that

[@VarHar-x1k]

Lithium ion is completely different than (LiFePO4) batteries and don't use one instead of the other.

[@skumancer]

CTEK is also a great option!

[@tonyrebeiro]

It is much easier to replace the exciter module, with a custom built module. We have a hall sensor based, current sensing device and a voltage sensing module on the alternator output. These sensed signals are sent to an Arduino, which drives the rotor could(exciter current) via a PWM output, interfaced via a suitable MOSFET. This setup will work like a charm. I know, because I've done it already. Thank you.

[@cleversolarpower]

If i understand you correctly, you have a switch on the cable from alternator to go into a PWM. The current going into the PWM get's controlled by the current sensors?

[@tonyrebeiro]

@@cleversolarpower I don't understand, what you mean by 'switch'. In order to accurately track and control the alternator output, into the battery, we need voltage and current sensing. For the current sensing, I used a HALL based sensing module in series with the load and a voltage divider setup for the voltage sensing. Using an Arduino, I process these two signals accordingly and derive an appropriate PWM signal output from Arduino, which is interfaced via a MOSFET, to drive the alternator rotor electro-magnet.(exciter current) The original AVR module is removed from the alternator and not required for this setup. Arduino controls the alternator, as per the code I've written. And in this code, I can now dynamically control the output current, which is directly controlled by the voltage, which is actually a Constant Current setup. And since voltage monitoring is available, I can drop the charging current, as needed, when the battery reaches 80% charge level.

[@Wigwhom86]

@@tonyrebeirovery cool

[@stanleybest8833]

Zeftronics regulators control voltage and amperage. Charge any battery of the correct voltage.

[@deborahdoyle6743]

Excellent video. Thank you.

[@andreagrandi91]

what ampere do i have to use?

[@cleversolarpower]

Over 9000!

[@andreagrandi91]

@@cleversolarpower what do you mean? can i use a dcdc charger of 20ah connected to my 100ah lithium battery?

[@freespirit5944]

So why not use an inverter like the renogy 1000w dc to ac from alternator to charge the battery or power instead? That would increase the wattage therfore charge quicker especially when solar is unreliable

[@cleversolarpower]

Car alternators produce 12VDC, not AC.

[@freespirit5944]

@@cleversolarpower yes, that's exactly why you would connect a dc to ac inverter to your car battery. Then you can plug your battery bank into it and charge as if you were charging it from the wall. There would be a slight energy loss due to the conversion but you'd still be able to get 750 - 800 watts from the inverter which is more than most dc to dc chargers provide.

[@zenzen9131]

Perfectly explained :)

[@anabelamino-wr6rk]

Thanks for video very useful ❤

[@willwalthamforest8706]

Why not have a hybrid leisure bank with lead acid and lifepo4 in parallel? No need for a dc to dc charger because I think.

[@creativegoot]

Why to use DC-DC charger at 50% of the rated current of the alternator ?

[@librulcunspirisy]

So you don't blow up your alternator

[@ptcclatlptcclatl1683]

Why not wire the DC to DC directly to the alternator?

[@cleversolarpower]

It's hard to reach and the battery already has terminals on it.

[@Energy_69]

My car alternator is 140V ,..I would like to attach a 12v 100Ah lithium battery ,…but I do find it unnecessary to install DC to DC charger ! Battery charging voltage is 14.6V ,…while my car alternator doesn’t reach that high only 14V I have seen some videos when the car is switched on but not driving , only produces around 250 watt to 300watt ,..when hard accelerating it climbs to around 400 watt or 450 watt only some time might reach split second spike to around 500 watt ,..but as I said must be some crazy accelerating , it’s impossible to keep that kind of rhythm would damage the engine ! So based on facts, and my style of driving,..I don’t think I would exceed 350-400 watt maybe even less while driving , facts going against the DC -DC charger ! I would like your advice based on this information, do I need DC to DC or not ?

[@cleversolarpower]

I assume you meant 14.0V. If your lithium battery is depleted, the alternator will still deliver a lot of current. The reason you are seeing 300W is because the lead acid starter battery is charged. You can try it and let us know the results 😉

[@Energy_69]

@@cleversolarpower Thank you for your reply I want to buy a 12v 100ah lithium battery to power my 12v fridge freezer during the summer while travelling with my car,..but the problem remains charging the battery, I do not want power station or portable solar they are too expensive and not very useful to me , I just need some power for the fridge when the engine is off ,…I’m thinking to use the alternator when the engine is running to charge the 12 volt 100ah lithium battery,..but don’t know what is the best idea ! Some people say use relay , some like you say dc to dc ,.not sure what is the cheapest and efficient way to charge 12vl 100ah lithium battery and to keep the fridge running ,..I hope you have some kind of advice thank you

[@gauravsinghsays]

How to diy DC dc charger

[@cleversolarpower]

I don't have experience with that.

[@GaryRust-xj7yt]

I have a Renogy 20A DC to DC battery charger that has been installed as per Renogy's info. When the charger is in operation for about 2-3 minutes the cooling fan starts and within another 3 minutes of operation the fuse trips. The green led is on during this period. Can you suggest where my problem might be.

[@cleversolarpower]

Fuse size: 20A*1.25=25A minimum. Which fuse do you have installed? Send me an email because i don't get notified of replies here.

[@zaha4716]

Plz Why multiply by 1.25?

[@cleversolarpower]

Required safety factor by the nec

[@gramos9115]

I have a cat with 2 engines with 60 amp alternators . I have installed 3x 100a lithium batteries . one engine battery which is connected to start both engines (VP 10hp) I have fitted a Victron DC/DC charger from the starter battery to the 3 lithium batteries . how can I stop the 2nd engine alternator from charging the lithium batteries ? My concern is that the 2nd engine alternator will overheat ?

[@cleversolarpower]

🎁 Free Diagrams: cleversolarpower.com 📖 My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified

[@davidwright1752]

Renogy dc dc charger the settings for the dip switchers would be handy not clearly available not even. Renogy

[@cleversolarpower]

It's all written in the manual. There is a dip switch where you can halve the current as well. So if you only want to use 30A on the 60A DC to DC charger, you can do so and there would be less heat generation -> better efficiency.

[@Sylvan_dB]

No, this is wrong. The sensitive part of the system is between the DC:DC and the battery being charged. The DC:DC should be near the battery it is charging with as short and heavy of wires as practical. If the charger has remote sense it can be further away, but most do not. The wiring between alternator and DC:DC just needs to be heavy enough to be safe, and a bit larger to be efficient. That side is not sensitive to voltage drop. If you are charging a 24 or 48 volt LiFePO4 then the voltage is definitely higher at the battery being charged. And if you fully charge a 12v LiFePO4 its finish voltage will also be higher than a modern 12v alternator+starter system (typically drops to well under 14v, LiFePO4 needs 14.2 to 14.6 to fully charge in a reasonable time).

[@cleversolarpower]

Yes, this is what I'm saying in the video. Wires should stay under a 3% voltage drop, so not as big as possible because it would cost a lot.

[@utube521]

why can U not just use a resistor to the lith bat, something like 0.5 Ohm 500W? still more effective that the 200 dollar dc 2 dc? this will supply your lith bat with about 30A of charging. Not OK ???

[@cleversolarpower]

A resistor doesn't know when a battery is full. You BMS will protect the battery though and turn off the BMS so there is no charge coming into the battery so it doesn't get overcharged. But then you cannot use your loads because the battery is disconnected.

[@leeinwis]

@@cleversolarpower BAM !

[@stuartstuart866]

I purchased a bluetooth monitored 100Ah LiFePO battery . It would be a great addition if battery manufacturers allowed owners to set their own charge rate from an app. This way no other expenses like heavier wires or DC to DC devices would be required at slow charge rates. Hmm, maybe even an interior charge converter so you could charge directly from solar panels as well. There is so much empty space in battery cases, maybe this could be done?

[@cleversolarpower]

I never heard of regulating the current input of a battery with the BMS. What brand does this?

[@fratermus5502]

@@cleversolarpowerSome high-end batts will talk to an external regulator over CANBUS to control alternator output. I don't know of any retail BMS that limit charging current to a given level.

[@mercedes-benz2127]

thank you for your videos. Not exactly solar, but my current project is to "merry" agm with lifpo in a car with simple parallel connection. my lifepo can draw up to 100A when it's not full. can I use resistor to limit this amperage (to ease generator and extend the batt. life) to about 30A and what resistor parameters should I use? thank you. here is the first video in this project: kzbin.info/www/bejne/laWwanhnfrhnipI

[@cleversolarpower]

You should not use a resistor.

[@philbrooke-little7082]

These are not needed, all you do is effectively add the lead acid resistance to the lithium charge path and the simplest way to do this is to simply extend the charging lead. Because the charge curve of the lithium is so flat the current and voltage drop remain almost constant. 100s of boaters have done this and saved a lot of money. DC-DC chargers are expensive, inefficient and often limit the current more than needed. You are actually using the voltage drop of the cables to your advantage. You only increase the length, you always keep the CSA large enough to carry the maximum rated current of the alternator. It is also perfectly possible to fry an alternator with a DC-DC converter. I use the long wire method on my boat and have been for some years and it works fine. My truck sadly has a 24v engine system and 12v domestic and so this uses and Orion horribleness. 70A 24v alternator, 30A Orion meaning it takes only around 20A (wasting 120W) from the alternator which is capable of a lot more. Needless to say the ‘lithium profile’ default of the thing was designed to damage the batteries through overcharging over time with a 2hr absorb at 14.2v going completely against cell manufacturer’s recommendations but it will of course mean they sell more batteries by reducing their lifespan.

[@cleversolarpower]

Did you watch until the end? I talked about this, but it's risky if you don't know what you are doing. If you do not look at the voltage of the starter battery and leave it on while the alternator is not running, you can drain the starter battery. You can set the charging parameters of the orion to a lower voltage, so your battery doesn't get 'overcharged'. Its possible, but i do not advice it ;)

[@philbrooke-little7082]

@@cleversolarpower I did watch to the end. You use a conventional dumb split charging relay from the starter battery operated by the D+ (warning light) terminal. I have suitably modified the Orion settings to avoid it overcharging the Renogy dumb battery. I will be fitting a JBD BMS, which I have lying around, to the Renogy batteries to give them management capabilities, rather than last ditch protection, and just leave the one in the battery to deal with balancing and cell over / under voltage. The JBD can then act as an overall charge protection from the various charge sources, some of which can’t be modified.

[@rickss69]

The problem is not the charging...it's the BMS. If it shuts down for any reason there will be a spike which will kill most electronics. If you had a lead/acid battery hooked to the lithium battery you would be safe, but who wants to run dual batteries just to have a lithium.

[@cleversolarpower]

Never had a voltage spike from a BMS that turns off.

[@nigelshindler6334]

On my canal boat I have retained the SLA batteries as well as the lithium partly for this reason. But of course the extra weight is not an issue on a 16 ton steel boat!

[@ntal5859]

​@@nigelshindler6334 You say that now but wait til your back goes and you have to lift it.lmao

[@nigelshindler6334]

​@@ntal5859a very good point but if you really had a bad back you wouldn't be able to run a narrowboat - you wouldn't even be able to get into the engine compartment! But I should put my hands up and admit that I get the marina engineers to move things like batteries for me😁

[@veganpotterthevegan]

Lithium is a great way to go for your second battery. If you can get your primary battery out of your engine bay, it'll make a great primary battery too if you don't live somewhere with very low temperatures

[@hufman9807]

Should be called, "charging lithium battery with lead acid"...

[@showtime302]

3 hours is much too long to recharge in car audio unacceptable

[@mikez9929]

😂 'promo sm'

[@SteveWrightNZ]

Maybe if you read about Kirchhoff's circuit laws you would see what really happens...

[@cleversolarpower]

Please explain your findings in the comments. We are curious to hear your take on it.

[@SteveWrightNZ]

@@cleversolarpower You want me to teach you Kirchhoff's circuit laws in the youtube comments? Draw the equialent circuit for the source and the load, including the internal resistances and see for yourself.

[@themadmachinist8637]

I mean... I'd like to know what this is? I'm not an expert. I came here to learn. How about sharing what you know instead of comparing dick sizes?

[@reveal-lk6ip]

The author! Have you eaten too many mushrooms? During engine start, the starter consumes more than 250-300 amperes!! Your DC-DC converter connected in parallel to the battery will die in seconds!

[@cleversolarpower]

I don't think you know circuitry. When the engine starts doesn't mean it gets sent to your DC to DC controller. If you put on a kettle, your lights are not going to shine brighter.