Lead Acid / AGM vs Lithium for Off Grid Solar - How to Choose Part 1 of 2

[@knurlgnar24]

I have seen quite of bit of misleading information regarding Lithium and Lead Acid batteries on youTube recently and wanted to make this video to clear some things up - or muddy the waters depending on your perspective. This video took more time than my typical planned but non-scripted style so please let me know if you like or dislike this type of content. Thanks for watching!

[@jeffwhite3021]

Perfectly timed release. I am in the process of shopping for a battery bank right now. Appreciate this!

[@knurlgnar24]

@@jeffwhite3021 I'll release part 2 in a few days. Hope the video helps you choose the right batteries. Thanks for the comment!

[@n3lee]

@@knurlgnar24 I've got some of my sites switching to Battleborn's for standby at -48v in telecom applications. I too was curious about the trickle charge voltage - I set it to what battleborn recommended to me: -Bulk/absorb 56.8 - 58.4(we usually recommend 57.6v) -Float 54.4 or lower; if the float is above 55.2 then its not good for the battery long term. -No equalization(or set it to 57.6v), no temperature compensation and absorption time is 20 minutes per battery(if its an option). I'm utilizing a Duracomm -48v/12amp BMS unit to charge a 100ah array; so far, the results have been excellent - as i'm sure you're about to get to in your next installment.

[@chriskennedy7534]

Love the details you go into More info the better as far as I'm concerned You've never wasted time just talking rubbish as most others do Appreciate your time n effort to pass on Genuine info

[@carmadme]

From this video at least I think I’m right in needing lithium Mainly because I will be using ~80% over several days to a week (assuming little to no charge during the day) And due to noise considerations and working hours I often cannot get a full charge for several weeks this is of corse in winter when there’s very little good sunlight hours here

[@scruff7559]

Oh wow. First view. I knew you'd be one of the few (only) No BS Versions. Love your work dude.

[@scruff7559]

I agree which is to say my scientific findings concur thus far. If you want the silver bullet (you already have it of sorts) it's MorningStar's charge algorithm that charges the lead battery to SG 1.28. This is the ONLY CHARGER ON THE MARKET TO DO THIS, that I have found. So next we can dispell the myth that lead needs to be charged once a week. If you have a proper charger (that you can't buy for a mains source) then this is not necessary. The premise that you need to charge lead once a week is based on janky chargers only pushing electrolyte to SG 1.265. Buy charger, buy hydrometer then ask the charger manufacturer for your money back because it only charges to 90%.

[@knurlgnar24]

@@scruff7559 That's very interesting - I'll have to look into it.

[@scruff7559]

Really? I've every mains charger I have ever tested failing to meet specification. MasterVolt, Ctek, Studer, Victron, Sterling to name but a few. I expect it these days. Judging by the business they do and peoples' uptake of marketing and Bluetooth over test instrumentation and evidence I'm reluctant to say more than a handful of people have enough sense to notice. It was my holy grail for years finding a charger that charges a battery. I build mains chargers by using PSUs on the solar inputs of MS charge controllers it's such a big problem. Saves a lot of money though, feature rich mains/solar hybrid charger. I've a 2kW mains / 4kW solar unit I built for ~€350. 9V > 72V battery compatibility. I've never replaced a battery I bought from new in a system I built around MS. (no association by the way..just easier than PSUs)

[@scruff7559]

@cody austin build yer own brother www.fieldlines.com/index.php/topic,150161.msg1053459.html#msg1053459

[@WillProwse]

Battleborn costs 4x more than building a DIY LiFePO4 pack with high quality cells that can provide 3000+ full cycles. Also, the battleborn is extremely heavy compared to aluminum cased prismatic cell packs. Battleborn is not good for weight comparison. You can make a 12.8V (4S)280Ah LiFePO4 pack with 5000 cycles (at solar use c rates), BMS included, for $500. LiFePO4 is cheaper and lasts much longer than lead acid. And it's more efficient. Which means less money spent on solar panels. I would conclude that lithium is much cheaper than lead acid. Not drop in solutions, but diy packs. (or a sok battery) and anecdotally, I have had lead acid batteries fail often. And I maintained them. I have never had a lithium battery fail. That's from living off-grid for 9 years. Also, the safety of LiFePO4 is better than lead acid. No harmful gases that require ventilation. BMS makes the LiFePO4 battery fool proof. Ocpd, lvd and hvd, that the lead acid battery do not have. Also, the coulombic efficiency difference and usable capacity should be considered. This difference alone make LiFePO4 light years ahead of lead acid. I made a long video where I show my numbers if you want. It's called lithium is cheaper than lead acid. I substantiate my claim with data as well

[@WillProwse]

Have you used lithium batteries before? There are lots of chemistries available. I can't seem to find any videos of yours using them. I bet you would love them.

[@WillProwse]

Also, if cycle life of lead acid is 4500 at 20% dod, you will need to buy 5x the batteries to have the same usable capacity as LiFePO4. And yes, usable capacity is 100% when used for solar. C rate is low so you can do full cycles and still hit high numbers. Also, when LiFePO4 is at 80%, you can still use it. Lead acid usually has a few bad cells at 1000 cycles even when you baby them

[@WillProwse]

Oh also, I like lead acid for CCA and working temperature range. They are great as starter batteries

[@krz8888888]

I was expecting you to chime in as a proponent of lithium chemistry

[@WillProwse]

@@lexiecrewther7038 but volumetric density wise, the cca of small lead acids is good. Not so much for LiFePO4. LTO would be great as a starter battery but it wasn't covered in this video unfortunately

[@Resleeved]

Finally some explanations on KZbin from someone who actually knows what he is talking about. Look forward to more videos! Would be great if you could explain what some of the components actually do that you point out in your tear downs.

[@knurlgnar24]

Which tear downs are you referring to? I am curious as I haven't been making many videos lately and enjoy those types of projects.

[@Resleeved]

@@knurlgnar24 The 1200w 20A AliExpress PSU. Hope you find the time to keep up the videos 👍

[@TruthCeeker333]

Glad I stayed subbed. Always look forward to your explanations! Blessings!!!

[@andrewswingler]

thank you. this was great. finally someone who knows what they are talking about. the big issue w lead is chronic undercharging; this is the main failure mode for off grid. it's actually relatively hard to complete the required ah reconciliation with solar... but once this is dialled in lead is much more economic... and robust!

[@mekuranda]

In the charge discharge cycles I found that even cheap Lithium allowed approx 4 times the usable energy as the solar charging window for me was around 4 to 5 hours and that would fully charge the lithium but only 20 t0 30 percent of my AGMs...

[@ericknoll3278]

awesome unbiased comparison im off grid and the rhetoric about this is daunting a problem i have with my agm is percent of charge. you only have what the voltage is to go by

[@knurlgnar24]

Voltage only gives a rough idea of SOC as you are aware. Coulomb (amp*time) counting is the way around this. On most watt-hour meters you can set a recharge ratio of coulombs in vs out (or it is hard set to something like 110%) and then they reset it each time it detects a full charge. Still just an estimate but it gets you closer. This is also how lithium battery charge meters work as voltage is even less useful for measuring SOC on lithium.

[@ChrisEdwardsRestoration]

i know you prob dont even read comments with 62 thousand subs, but you make a difference. thank you for your knowledge and sharing it!

[@knurlgnar24]

I'm sorry, I don't have time to read your comment or tell you that I appreciate the sub and your feedback. :)

[@curtchase3730]

Wow! Exactly what I was looking for! Now I am convinced that if I were to go solar/wind (off grid), I'd jump on those huge heavy Trojan's in a heartbeat. Just being 6 volts each, helps in balancing and if one pukes, you're not throwing away 5 good cells as w/a 12 volt battery. I really wish there were more options for 2 volt single cell FLA! Ya, more bulky due to packaging, but now we have even more control, and probably a bit lighter (per cell) than one huge 6 volt unit. Nice work!

[@MrSummitville]

What is wrong with WHOPPING 1,110Ah @ 12 Volts = 6 X Trojan L16RE2V at $300 each = $1,800. Will last for 7 years at 30% DOD daily. Yes ... a whopping 1,110Ah not a measly 100AH !!!

[@brianhawki7149]

Just awesome your back with regular video releases & sharing your knowledge again. Thanks !

[@kevinscott7340]

I switched to lithium 2 years ago the biggest difference is voltage drop on agm when you put a load on agm the volts go low and shuts of inverter it doesn't do that with lithium plus I pay a third the price as battle born I make my own

[@ricklearned1686]

Yes you are describing the Peukert effect which is another reason you have tto buy twice the capacity in Pb batteries.

[@kevinscott7340]

@Yog Sothothologist by prismatic cells and add a bms

[@jimbean2589]

Hats off to you, very understandable for a beginner trying to get a solar set up off the ground. You make me feel smart for settling on 6 volt 390 amp hr batteries in series and then paralleled for a 24 volt system for about 400$ each. I think I will by two more!

[@jaykalisekdc3767]

DUDE! You're back! I missed your videos. Welcome back.

[@knurlgnar24]

Thanks!

[@austin30233]

Welcome Back to KZbin! BEdtime. Will watch later, lol

[@NickOvchinnikov]

From what I understand... This is the most practical information I've heard

[@emircenk3621]

Love ppl who realy know stuff and then even share it !!! Best man

[@thepsycholist207]

Anecdotal comment on Lithium Ion. I'm still rocking an iPhone 4. From like 2012. I'm not some tech luddite (else why would I be here) but for various reasons I just haven't gotten around to replacing it. I still get about 3 days standby. And to be honest I've not noticed a decrease in battery life. But then so very few apps (aside from Gmail and the web browser and Kindle) work that I suppose that's why. Love that you're back and appreciate the content.

[@knurlgnar24]

Nice on the phone battery! Myself I've had decent luck with phones and terrible luck with laptops. My view of it is that you have a single cell failure point and single data point. For every person that had their phone battery last 8 years many more had them last less than 3. And in a large system there are thousands of cells greatly upping the failure rate of the total system.

[@thepsycholist207]

@@knurlgnar24 Yeah I'm sure this battery is some sort of weird outlier. I've generally also had bad experiences with Lithium Ion in laptops. And in portable gaming devices. Aside from Nintendo where I've had ancient 15 year old (think Nintendo Gameboy SP) devices still power on despite being neglected for all that time . While I'm sure their battery is junk at this point it's still impressive to me.

[@knurlgnar24]

@@thepsycholist207 An odd note that has nothing to do with this topic except that it pertains to batteries: None of my NES game carts from the 1980's have had any issues with their batteries. They all save game data just fine including data still saved from my childhood. Sometimes we're just lucky I guess!

[@kencrane6420]

After the day I've had I needed a Knurlgnar video. Thank you.

[@geocha1962]

What about the charging curve of the led acid? It takes hours to charge a led acid bank over 80% SOC to 100%. In a daily cycle that's impossible. Lithium goes to 100% at 1c.

[@jamesscott1932]

Yes, another significant detriment to the flooded lead acid battery is the caustic vapor it releases. When a flooded lead acid battery is used in a high vibration, high temperature operation, it can make a terrific mess and cause otherwise additional maintenance or shorter life to surrounding equipment. Excellent lecture.

[@knurlgnar24]

The Northstar batteries in this comparison can be charged from 0% SOC to 100% SOC in under 2 hours total including that 80% to 100% range. It depends on the battery you are comparing to, but I agree that this is a benefit to lithium.

[@ricklearned1686]

@@knurlgnar24 and of course the charging current. I can charge my Lithiums faster because I can charge them at higher C rate than even the Northstars you mentioned.

[@jburdman7]

Love the lead info. I'm anticipating more rejuvenation videos. How much and what sort of over-volting and heat abuse is helpful in getting more life from a lead battery? How should we conceptualize the voltage swings during charging? That info is gold. Thanks for sharing. Re this video: Battleborn includes a charge controller so your cost comparison is not apples to apples. I disagree with the way you are conceptualizing cycle life. You have your mindset in the charts, not in the battery. All else being equal, from a lead battery's perspective, its death clock ticks when it is sitting around at less than fully charged, which is 21ish hours per day. A LiFePO4 cell has its life counter ticking when it is abused at temperature extremes especially at the ends of SoC. Lithium could not care less about sitting around half charged, which is good because that is what they are going to do in an off grid installation. A lithium battery, if kept at proper temperatures, might blow the doors off of its rated cycle life. I'm not saying that you are definitely incorrect on cycle life, but your view seems shaded by your investment in lead. Given a graph of how long each chemistry is held at different SoCs in a typical off grid install and Lithium will likely win. The advantage of lead is for back-up because it likes to stay fully charged. Off grid might "want" to be fully charged but that ship sails every evening at sunset. Respect lithium's fussy temperature requirements and they will last a long time. I have a $20 LiFePO4 solar light which has been cycled daily for about a decade and counting. Occasionally charged on bright, sub zero days too . It's still going anyway. A quality cell, properly cared for? Don't be so certain that it will not out live you. Also, the posts here pointing out that lead chemistries die, but lithium fades away, are real. A lead at 80% is a time bomb. A lithium at 60% keeps on squeaking and rattling and limping along.

[@guyztruth4593]

I'm fairly new to solar, but went with agm batteries as they are stored indoors. I truly wish I had just bit the bullet and went with Lithium batteries. I'm in western MA and not getting much sun light here in the fall season, I'm sure even less in winter. The agm batteries just do not charge fast enough and discharge very quickly. Sometimes only drawing 1-3 amps out of an 800ah bank shuts down the inverter within hours. I don't have any confidence in the agm batteries at all at this point and have2 x 200ah lithium on the way. In comparison I have a small 300w lithium solar generator that seems to out last the agms. On paper maybe agm looks good, but in my area or maybe it's my system... they do not have any stamina.

[@rokashardware235]

its sad that you didnt buy lead acid because u can convert it to lead-alum but with some agm batteries it also works here is a tutorial: kzbin.info/www/bejne/jom5kmV5hpKJbc0&ab_channel=ELECTRONICS Lead alum can be discharged to 0 v and will not get any damage from that also the battery lasts about one lifetime with alum but alum is just a recomendation if u want do ur own tests with it. i would recommend buying an MPPT charge controller for ur solar system it gets the most energy out of ur solar panels (up to 30% more ) its also important to have the Solarpanels aligned the right way to the sun with as little as possible shadows so just play around with the placement of ur solarpanels. sorry if my english is broken

[@dosomething7930]

Hi , add a big super cap to your battery in parallel . I have added a 58f cap to my 12v 900ah tired bank and wont look back, no problems starting pumps etc , soon I'll add a 500f . The cap takes away torture from the battery .

[@michaelmedicworldoftanks33fps]

I had the same experience and bought my 1st lithium and it's 10x more power than any AGM or lead acid of same rated capacity that I ever owned before that plus the huge 12.6v lithium's advantage when down to 0% capacity is just unmatched and unbeatable by any AGM out there

[@AftermarketCRX]

I agree on the cycle life for flooded lead acid at 80%. At my last job we had electric forklifts. Each had an almost 3000lb battery in them, which doubled as a counterweight. They were run down that hard every day, and lasted about 5 years before needing replacement.

[@knurlgnar24]

Always interesting to hear real data from field use. Thanks for the information.

[@MrSummitville]

@@knurlgnar24 Fork Lift batteries are the ultimate in FLA deep cycle. Antimony - uses more water, higher self-discharge but increased plate strength. And they have very thick plates = long life.

[@Joemama555]

Could you speak on NiMH prius style of batteries at some time?

[@cyumadbrosummit3534]

I was using 4 massive 100+ pound telecomm AGM batteries for 5 years (still in use for my battery pack spot welder). But this year I switched to Model S modules and I absolutely love them for home storage. Nearly impossible to get appreciable sag out of them in a 3p configuration and the TSLA BMS is rock solid. Let's do some more inverter torture tests as the market is flush with new players since your last video.

[@knurlgnar24]

Nice setup. Automotive electronics are in a different class than industrial/commercial electronics so while I don't know much about Tesla's BMS I am sure it will be highly reliable in a stationary environment!

[@nate8088]

You definitely don't save money going with lithium, but you save sanity. At least, in a RV/Van setting with primarily solar and only occasional fast charges from shore power. Obviously in a traditional off-grid house/cabin, your use case would differ significantly. I was willing to pay the premium to have the flexibility and reliability. (And I do recognize that I was paying more for that.)

[@knurlgnar24]

It sounds like you made a solid choice based on grounded data and not marketing hype. If I had an RV I would also seriously consider lithium.

[@danwhitehorse1492]

I noticed on another of your videos some one asked a question about if there was a way to know when the power comes back on after an outage. Of coarse after you are running your inverter. Here in Calif. on PG&E smart meters there is a little LED green light on the Right side of the meter in the center that flashes when the power comes back on ! I noticed by accident after a rolling black out. I'd also like to thank you for you videos, very helpful. I have system set up Similar to your battery back up. My inverter took a dump after 5 years. It Had A ground on the frame. Worked well when it was still alive. ! lol I purchased a Renogy 2000 watt inverter, needless to say the new ground fault inverters are a challenge, I had the ground hooked to the frame like the other on and it wouldn't do squat ! worked if I hooked a drill or a refrigerator to it but when I hard wired it nothing just the ground fault warning. Your video's are amazing ! Went right to the problem after watching them. Stupid ground wire ! Thanks Keep up the great job, your friend, dan

[@lewiswood88]

Glad to have you back

[@RickRose]

I fully agree, and anticipated, that lithium ion batteries' primary (sole?) benefit is weight savings--certainly useful regarding electric cars and weed whackers. A friend who owns a Tesla confirmed the guidance he received that 20%-80% is the sweet spot for maintaining his batteries. What surprised me is the apparent advantage of flooded cell vs. AGM. Why the heck are we upcharged for AGM batteries for our cars, and why are they touted as the "premium" choice? Always enjoy your videos--keep 'em coming!

[@knurlgnar24]

I actually do like AGM for cars personally. Flooded batteries tend to seep/leak electrolyte after they get older even if they are 'sealed valve regulated' and can damage iron and aluminum that they drool on. I lost an AC pipe to this a long time ago that required repair. AGM doesn't do this. Me? Yeah, I still buy quality flooded car batteries. They usually last 10 years and that's good enough for me.

[@RickRose]

@@knurlgnar24 Entropy rules the universe. All we ever do is buy time.

[@michaelweyrick8253]

thanks for all your projects and info. Do you any experience with any of the carbon foam batteries?

[@jcschwarb]

This is eye popping analysis. Thank you for clarifying and changing my understanding. Saved me tons of $$$

[@knurlgnar24]

Thanks for the comment and I am happy you found this analysis useful. It is nearly impossible to find scientifically useful data driven information on this subject which was the motivation for this video.

[@JT-lq4yd]

Excellent topic. Unscripted is more natural. I would love to have a forklift battery for off grid energy storage.

[@markawbolton]

That's what I have ... 4 x 6 volt forklift batteries. The maintenece is negligible. They are in a 9 ton truck / mobile home so the weight doesn't bother me.

[@DesmondNoel]

What's about voltage sag on lights and computers

[@knurlgnar24]

Voltage sag on the AC output side is an inverter issue rather than a battery issue. Computers won't care but lights can be somewhat annoying if voltage isn't stable. Lithium will tend to have better 'voltage sag' performance on load steps than lead acid when comparing undersized battery setups that most people tend to have. As I mentioned in the video RVs, for example, always have undersized battery banks as a matter of necessity. For stationary use in homes I would say this is a non-issue.

[@larrybell4599]

Great comparison! This is very useful information. Thank you for sharing your results.

[@dashtesla]

Really good video, looking forward to part 2

[@551moley]

I went for AGM lead carbon (top brand) at 4 years old, the 320 ah is down to about 70ah, the system has always been connected to the same brand inverters etc and set to the suggested settings, with hindsight the batteries were way off spec 18 months ago finally now changing them because the voltage drops too low. Breaking into one battery it's virtually dried out? So it's possible we may recover some more use from them, my new "maintenance" free batteries at least have caps to unseal and check in future unlike the last lot.

[@knurlgnar24]

I suspect sulfation. Try charging them at 15V for 24hrs and re-test capacity. If it increased repeat. I'd be surprised if you can't recover them to nearly 100%.

[@551moley]

@knurlgnar24 Thanks for the suggestion, I've got nearly a litre of water in one battery, you can't see the plates inside just a yellow perforated membrane, I'm slowly adding water until it looks moist, I assume it will rehydrate the gel, the only access is through an 8mm vent hole. Very encouraging reply thank you.

[@knurlgnar24]

@@551moley Are your batteries Gell? If so please do NOT charge at 15V as it may damage them. Lead carbon batteries I am familiar with are AGM and can handle this desulfation technique better.

[@hylofthacker]

Thanks for all this data.

[@JohnSmith-qd8po]

Could you possibly touch on charging efficiencies/times of each battery type ?

[@knurlgnar24]

Part2 covers this. Should be published in a few days.

[@JohnSmith-qd8po]

@@knurlgnar24 Awesome. Thanks.

[@richardblais6282]

Lithium batteries don't seem to like being recharged in temperatures below 25 ° F or -4 ° C, which is important to me in Canada.

[@knurlgnar24]

Important for me too. Their discharge capacity also suffers at low temps which few people talk about. At -40F their usable capacity is zero. Lead acid does poorly there too but at least it still functions as a battery.

[@richardblais6282]

@@knurlgnar24 My electrical installation is completely outside in a shipping container without heating during the winter so I will keep my lead acid batteries.

[@MrSummitville]

@@knurlgnar24 Insulation? And now ... self-heating Li-Ion batteries!

[@redsquirrelftw]

That was a good analysis. I do think lithium will get better and cheaper, but right now flooded lead acid is still the way to go. As long as you maintain them such as adding distilled water they will last a long time. One plus for lithium is that they can't spill, so they are suitable in vehicles. AGM might be ok for a vehicle but at that price it may almost be worth spending more on lithium as space will matter more too. But one downside of lithium is the more complicated electronics needed. The Battleborn has that all built in, but if you want to make a larger battery bank from cells you have more to worry about to make sure you get it right. Lithium is also harder to buy. I don't really see lot of places, at least in Canada, where you can buy the cells. Basically, at this point if building a system I would go with flooded acid, and when they die, lithium will probably be cheaper and easier to get at that point and be worth revisiting. We still use flooded acid in telecom, and I'm sure when the price is right they will start switching to lithium, but lithium is more complicated to setup. With flooded acid you put all the cells in series and set a constant float voltage and they are happy. In a backup application it's harder to start tracking current going into each cell and altering the voltage, because the load is running at same time too.

[@knurlgnar24]

I agree totally. Lithium will take over in time but for now Lead Acid still makes a good argument where weight isn't a factor. I expect them to live on for another century in specialized applications because there are some things that lead acid is really good at.

[@billpullen9627]

Can't find part 2 :( after buying 2 battleborns because my 200 ah agm died after 2 years, this is interesting.

[@volvo09]

It's coming

[@justsomeguy911]

He’ll probably post part 2 within a week or so.

[@danrolando7800]

Hello thank you for this video I thought it was absolutely amazing. How do I determine what size of inverter do I need for my home. I think it will be 15000+W for a 7k square ft house. Thanks in advance.

[@rhiantaylor3446]

A better attempt than most to do a fair comparison. One issue is that Lithium "12v" batteries are still near their early-adopter pricing. I just watched a youtuber (Freely Roaming) claim that he can buy 12v-worth of 280ah Li Iron cells for sub US$400 so only 15% of the price per KWh of your Battle Born. Despite your comments I still feel Lithium is a better bet for a battery subject to significant daily discharge - you only have to look at Tesla's recent stats on battery degradation. I was certainly surprised by your comment that Lithium is seriously affected by being charged above 80%. For max life its best to avoid 100% charge but "seriously affected" - I don't think so.

[@knurlgnar24]

I think the discrepancy between us comes from defining "100% SOC". A design engineer might say the battery has 110Ah at 100%, but tell the tech writer to instruct the customer that 100% is 90Ah to prolong battery life. Management then comes in and tells everyone they have to compete with Company X which specs their similar battery at 100Ah. So 100Ah goes into the spec even though it is an arbitrary number and the reliability engineer has to bite their tongue to preserve their position - after all it won't come back as a warranty expense for another 5-10 years and by then he'll have moved on. Cycle life objectively does suffer severely if the top few percent of the battery capacity is used, however most reputable manufacturers define to the customer 100% to be closer to that 80% level so it tends to be invisible to most users. Also, most inexpensive cells you find online are not the capacity they advertise. I tried buying camera batteries a while back and ran into this - no one except the camera manufacturer advertised the correct Ah rating...

[@MrSummitville]

@Rhian Taylor - Do those cells come with a 10 YEAR WARRANTY?

[@1floggedhorse]

2 years on - Hybrid Grid-connected solar systems designed to use every last milliwatt rather than export it are getting common, even charging batteries late at night on cheap tariffs for use later, or even just to be sold back to the grid at a profit. Chuck electric cars into the pot! the choice gets harder. - but great video :) - where have you gone?

[@knurlgnar24]

Thanks Flogged, still here just not making many videos. KZbin and life have changed somewhat and despite having lots of video ideas I don't seem to get around to them for personal or practical reasons. I still think about going back to regular videos someday should things go in that direction, but the expected quality of videos has risen substantially since I stopped regularly making vids in 2014 raising the commitment bar.

[@noahriding5780]

So are forklift batteries the best thing to use then?

[@knurlgnar24]

That depends on a lot of factors that this video covers. For me they would not be the best, but for others they may be.

[@offgridinthepacificnorthwe3210]

Did I understand you to say that the depth of discharge on FLA does not effect cycle life? I have found quite the opposite to be true. I may have misunderstood you. I have found that in a off grid solar application FLA batteries typically are at a partial state of charge for many days in a row here in The Pacific North Wet. Sulfation is a real issue at partial SOC. It is a non issue with lithium. FLA also has an ever increasing resistance to taking a charge. When my L-16 batteries were new they took about 10% more energy to recharge than I took out. This drastically changes as time goes by. When my batteries were 5 years old it too 20% more. So far with Lithium ion NMC my batteries take a charge so fast I have the efficiency setting on my battery monitor set at 99%.

[@knurlgnar24]

DOD * Cycles determines life. DOD on its own is not important. 100x 60% DOD will be approx the same as 200x 30% DOD.

[@tracyrreed]

So if I want a 24v system I need four of them. Yeah, that's pricey but at 220lb each we are talking 880lb of batteries! I'm not sure how I would handle that.

[@unionse7en]

With NEC 2020 as long as the Inverter is UL9540 and compatible with Lead Acid.... does that mean the combination of said inverter with any Lead acid storage battery would be approved?

[@knurlgnar24]

I am not an authority with jurisdiction nor a lawyer, but I would think so so long as the lead acid storage system was compliant with all codes including ventilation, spillage management, and safety requirements including possible eyewash stations, lever style door handles, and acid spill remediation systems that you would be approved. As I understand from most practical feedback you just need to work with your local AWJ to make sure you are approved. They are usually very lenient so long as you work with them and are respectful. That isn't always the case of course but pissing them off is never a good idea.

[@dinushkam2444]

Was waiting for your video. So informative. Thanks keep up the great work

[@sergeantmagi]

Thanks for another great video. Can't wait for part 2 as my home battery bank is up for replacement!

[@knurlgnar24]

With all the comments I decided to make an addendum in part2 despite that making it an hour long. That will delay it a day or so but wanted to address some of the claims made in the comments and I thought it was important.

[@MyPlayHouse]

So nice to see you alive and kicking. Would have been nice if you had left a note :-/ I am also messing around with both Li-ion and AGM,, my AGM bank is old USP batteries and on there 15Year,, I have 24 of them so really want to squeeze all the life out of them. Any chance you would know how to improve on the gel,, it´s probably getting a bit dry,, can it be dissolved in distilled water, and make the battery last another year.

[@knurlgnar24]

I honestly don't know as much about gel battery technologies. AGM can handle adding water so long as you don't add too much (difficult to know how much to add). Does adding water to gel batteries work and does the gel 'soak up' the water homogenously? I'm not sure. If you have AGM and need to add water you can add but unless you re-do the thermal fusion seal you'll have to treat them much like maintenance free flooded batteries after opening.

[@dfpguitar]

excellent content! I am only beginning to learn about solar systems and battery types but I have never heard these arguments, and justified with data too! very refreshing to hear a fair comparison.

[@jackiemuenz4152]

Thanx for making more videos. I enjoy the same things u do. A lot of people on here if u rubbed their brain cells together at a rapid rate, would achieve near absolute zero. Im sure yours would keep my hands warm. Thanx again.

[@battistuzzijohn]

Hi... I love watching your videos. I have a very odd question. I am living in Italy and the cost per KWH are getting out of hand. I was thinking of getting a solar system..... ok till now nothing special as of a question. My father lives next door in an attached home and was thinking of sharing my solar system with my dads house with an ats switch without having 2 set ups. Is this even possible or am I better off with 2 solar systems? If I have opt for 2 systems is there some way we can share a huge battey instead of having 2 separate ones?

[@knurlgnar24]

I have no idea what the building codes are in Italy, but sharing batteries or using one setup with a branch to an ATS at your father's place would both work. I suspect this is something you'd have to do yourself as it wouldn't be a typical install and I doubt professional installers would be willing to deviate from what they are used to doing. Here in the USA building codes are strict and installers are terrified of liability should any tiny deviation from what they typically do cause a problem.

[@rpbajb]

What type of battery does the US Navy use in their submarines? Price is no object there, might give us a clue which is best.

[@knurlgnar24]

The engineering and financial requirements are entirely different for such an application. That's like saying "What type of engine does Formula 1 use in their cars? That's obviously the best engine for my Civic." Besides, the US Navy field nuclear powered subs. Any batteries are ancillary.

[@don1mclean]

Really enjoyed your systematic approach. Thank you.

[@Penguin545]

Zooms 200ah battery is currently $690 with a $45 off coupon bringing to to $645 plus tax with free shipping on Amazon- compared to the selected battleborn as priced in this video you get 2.94x the watts per dollar as listed on the spreadsheet, so if you utilized it to an 80% depth is discharge it is almost identical to the FLA. Pricing on zooms as of December 2021. I also intend to have this as a standby system for power outages so I’ll keep the 48v bank float voltage at about 50% of battery capacity to maximize battery life while in “cold storage” and if there is a power outage I’ll then start drawing power from a 2,100 watt PV array running 78dc/27 amps into a 3k GroWatt inverter/charge controller/ all in one unit.

[@knurlgnar24]

Pricing will continue to change in the market as technology progresses. The price I used here was that of a highly regarded mass production manufacturer and there were many lesser quality products that sold for far less available at the time of filming. Over time the products of reputable manufacturers will decrease and the situation may change, but there will always be those who try to sell lesser quality products at lower prices and claim parity with the big names.

[@Penguin545]

Not to detract from your content at all- it was a fantastic video and very insightful, just commenting that the lithium battery prices have been dropping rapidly in the last few years and so the math is rapidly moving around. I went with a zooms battery based on a Will Prowse video taking it apart and commenting that it was essentially a rebranded Chins battery but $100 cheaper, plus a slew of positive Amazon reviews. Any insight as to what kind of quality one might realistically expect from some of these cheaper lithium iron phosphates compared to battle borns? I felt like lithium made sense in my application because they will spend 99% of their life in cold storage rather than being used daily so I needed something that was low maintenance with a maximum shelf life- it seemed like overkill to shell out top dollar for name brand lithium’s if I wasn’t going to try to get 3,000+ cycles out of them with 365 day per year use. I guess if the zooms end up being POS’s then I’ll eat my words and live with $3,000 of buyers remorse 😔

[@rust2985]

I’ve been going back and forth for weeks on what chemistry of battery I wanted to go with… I decided to go with lithium because I wanted to try it, and it was by far the cheapest option. I got 200ah prismatic cells and built my own battery for less than half of the cost of flooded. I’m crossing my fingers that it’ll be reliable.

[@knurlgnar24]

That's the big question, I agree. I think you made a good choice for what it's worth. Buying name brand quality lithium batteries is very expensive but building your own or getting no-name grey market batteries is quite inexpensive. I'd make that gamble too given the right set of circumstances.

[@OleBrinch]

I really love that you are back. We need more people with there world based in facts and data and less in opinions and hear say. I have been thinking the same as you regarding DOD ad lifespan. I run 24 x OPzS1500 (1700 Ah) 2 volt cells. When I dived into the data on the cells I concludes the same as you describe. DOD does not matter on how much energy you can pass through the battery before end of life. Here are my calculations on a OPzS1500 cell: From data: 1000 cycles ved 90% DOD 1500 cycles ved 60% DOD 3000 cycles ved 30% DOD 4500 cycles ved 20% DOD Complete energy in and out before end of life: 90% DOD: 1000*0,9*1700*2=3060000 Wh=3060kWh 60% DOD: 1500*0,6*1700*2=3060000 Wh=3060kWh 30% DOD: 3000*0,3*1700*2=3060000 Wh=3060kWh 20% DOD: 4500*0,2*1700*2=3060000 Wh=3060kWh

[@knurlgnar24]

Great analysis!

[@slonon6410]

what voltage would a 35ah battery after drawing 35 amps for one hour?

[@knurlgnar24]

I wouldn't expect a 35ah battery to be able to supply 35a for one hour.

[@dexterroy]

Your videos are so informative. Keep up the good work.

[@ironhead65]

I am curious if you have ever looked into NiFe battery technology? I certainly recognize that was not the point of this video and I'm not saying that you should have included it, but I'm just curious if you have ever looked into that technology?

[@knurlgnar24]

Only on a cursory level as there isn't much good info on it. When it comes to lithium and lead acid there are numerous government sources with detailed test data as well as doctoral thesis and information available from engineering app notes in the industry. I've found none of that for NiFe so my info is limited. What I have found isn't very supportive of the technology aside for some very niche applications.

[@Godday_victor]

Please the links for the batteries

[@knurlgnar24]

battleborn is sold from the manufacturers site and I'd suggest starting with thesolarbiz for the other two. I've bought from them before and they offer good service.

[@robertoleszek8361]

Any info on alcad nicadm?

[@knurlgnar24]

I'd have to look into it. NiCad is generally a robust battery technology though and would still be in more widespread use were it not for the cadmium issue and government regulations effectively killing them off.

[@tomstdenis]

The comment about DoD at 12:30 is not supported by datasheets. For instance, FullRiver AGMs claim 5000 cycles of 10% DoD, 3000 cycles of 20% DOD, but only 500 cycles of 80% DOD. 500 x (80%/20%) is not 3000 (it's 2000). So yes, even shallow discharges wear the battery out deeper discharges do more damage (note: This is per their 2 hour test so I imagine the 80% DoD is at a higher discharge current meaning hotter batteries)

[@knurlgnar24]

The DOD vs cycle life curve depends on the specific battery but in general for batteries appropriate for off grid applications my assertion is true and well supported by manufacturer info. e.g. even from the info in your post the curve slopes the opposite way at 10% and 20% where deeper cycles are better for the battery. Without looking at the datasheet for that battery where is the mid-point? Probably around 30% or 40%. And if the mid-point where the slope inverts is at 40% then 40% is mid-way between 0 and 80, so in a simulation of typical cycling given year-round solar and load schedules you'll find average cycle depth to be nearly linear with lifetime. 5000*.1=500. 3000*.2=600. 500*.8=400. Add some points, plot out, and consider where you'll be cycling on average and with a sigma or two of variation in a real world application. Yup, cycle depth is of little consequence.

[@MikinessAnalog]

Since I would not be moving them, I would not be concerned about the weight of a battery (except maybe delivery charges) as long as it had endurance for off-grid storage.

[@knurlgnar24]

I second this. Unless it's a mobile application or the floor you're installing them on has a weight limit I don't understand why weight should be an issue. Sure, it's a pain to move a 200lb battery around but how often do you really need to? It's a pain to move my refrigerator too but I don't buy that based on weight.

[@aldogutierrez8240]

What about Lead Carbon?

[@knurlgnar24]

The two lead acid batteries I featured here were lead carbon. That is the most appropriate technology for solar applications today. *edit* for lead acid *edit* Older battery technologies like standard golf cart batteries can be used but they will perform significantly less well and I wouldn't even consider them for a full time install today.

[@solarandwindinsouthtexasda1473]

The flooded acid battery Abby's is how many years you still revive it and it still be good AGM and lithium-ion when is dead it is dead nothing else you could do about it

[@jameswilsin5348]

What abought a Tesla battery?

[@bdv861]

Your arguments against lithium make perfect sense....within the context of a fixed home system. But lugging hundreds of pounds of lead in a tiny teardrop travel trailer like mine is not a viable option. Lithium wins hands down. And the reality is, most people use a cheap flooded battery or batteries in their RV. Which makes a lithium comparison valid.

[@knurlgnar24]

I agree with your RV statement regarding lithium being a good choice in that application.

[@fratermus5502]

> lugging hundreds of pounds of lead in a tiny teardrop travel trailer like mine is not a viable option Hundreds of pounds of Pb would be 400Ah+. I've never see that much capacity in a teardrop. > most people use a cheap flooded battery or batteries in their RV No, they use actual deep cycle batteries, typically GC2 like the Trojan T-105. Weekenders and casuals use cheap batteries then wonder why they don't last a year.

[@BCElginTex]

Am i correct in assuming the kwh/$ is based on the cost of the batteries, not including shipping?

[@knurlgnar24]

I looked online and priced out shipping a pallet of batteries for a 20kwh battery bank to my zipcode so price includes shipping. These prices aren't the absolute lowest I found but are close to the lower price side of the spectrum.

[@BCElginTex]

@@knurlgnar24 cool!!!

[@linglingwang493]

I watched your video and thought you are a great tubing blogger. Are you interested in doing a review of pure sine wave inverters?

[@maxpower9340]

My mate brought 50 Lead Acid Deep Cycles used in submarines. 20 years later he still has to dump power into this emersion heater :)

[@SeanBZA]

Chose lead acid, and went for flooded, as those at least can easily be inspected and refilled as needed, plus I had limited ability to change float voltage, aside from moving them outside to allow them to run cooler than in the UPS. 18 months along and they are surviving.

[@Masteradamant]

I’m certainly looking to make lead acid batteries to save money; this helps ty. Really lithium is just better for a battery wall but there’s always a shelf design that could work for lead acid

[@knurlgnar24]

I would disagree that lithium is 'just better' for a battery bank. See my lead acid vs lithium battery bank videos for more details.

[@Masteradamant]

@@knurlgnar24 Actually I recently read that the 50 dollar 400 watt solar panels I ordered recommend using lead acid batteries only; why would they disclaim this? Regardless, lead acid is clearly less expensive so with an investors perspective, its worth considering lead acid over lithium to run a solar system.

[@mattmopar440]

I have a 4 8D deep cycle for my off-grid system I like the abuse lead acid flooded seem to hold up to the best. it is backbreaking work to swap them out every 5 years tho

[@knurlgnar24]

I'm curious, legit question - could you hire a moving company to do this work or will they not take this kind of job?

[@mattmopar440]

@@knurlgnar24 I work at a hospital and we have a company called all American movers they will literally move anything. Luckily for me I have a trailer with a lawn tractor so all I have to do is lift them out of the car into the trailer and than up into the rack

[@ObsessionoftheMonth]

Very well done, I am interested in the follow up videos.

[@VonBugle]

Would it be right to compare the round-trip efficiency of the batteries here? I was under the impression that discharging a lead acid at anything like 1c would severely diminish the capacity?

[@knurlgnar24]

Round trip efficiency matters and is higher in lithium chemistries but capacity under various loads is generally not a concern in off grid storage applications for the reasons mentioned in this series. 1c discharge will definitely result in a terrible capacity in lead acid - however in the context this video covers a system sized for a 1c discharge rate is likely to be not properly sized so I don't consider it to be relevant. Your specific application may require such discharge rates and if so then lithium has a clear advantage and I wouldn't even consider lead acid in that case.

[@VonBugle]

@@knurlgnar24 Ok, thanks for the explanation. I've always thought the trick with Lead acid battery banks is to have them as big as possible; to reduce the discharge current per battery so you can get as close as possible to the advertised capacity, ususally measured as the 20H rate. As an aside, your vids a few years ago taught me a lot, and it is good to see you making new ones!

[@thinkingimpaired5663]

Trojan batteries are indeed good batteries and yes costly. Had them on golf cart.

[@knurlgnar24]

They make many different types and grades of lead acid and are for sure one of the leading experts in that field. I see many people using their low cost models for solar (which are still somewhat pricey to be fair) but rarely see people using the batteries they specifically make for that purpose. A wrench will drive a nail into a 2x4, but I'd much rather use a hammer myself.

[@james10739]

Well on lithium iron phosphate the damage at fully charged or fully discharged is relative but not that big of a deal even if you do and it's more like the top 10% less so on the bottom end but

[@knurlgnar24]

I am quite sure Battle Born specs their 'fully charged' to be closer to that 80% or 90% level otherwise they'd struggle to get even 500 cycles. It all depends on what one defines 100% SOC to be. The engineer, the technician, and the user all have different definitions of that term. Damage is quite severe near 'design engineer 100% level' which is why manufacturers don't let consumers abuse the batteries that way, cutting off charge via the BMS at some level before that point.

[@james10739]

@@knurlgnar24 I think you have been looking at lithium ion batteries like lithium Cobalt oxide or something they have a cycle life of around 500 but lithium iron phosphate should be near 2000 to 3000 cycles to 80% according to different manufactures data sheets

[@WillProwse]

@@knurlgnar24 they are rated at 100Ah, pull around 102Ah, and the parallel cell packs test at 102-109AH. You can cycle those packs 3000 times at 100% dod, and 5000 times at 80% dod, till you hit 80% capacity. Biggest cycle life determinent factor when used for solar application (low c rate) would be the ambient temperature and how the charging system is sized.

[@VinoVeritas_]

@@WillProwse I find it disingenuous for him to quote the upper 20% and lower 20% of the voltage as danger areas of LiFePo4 without providing any evidence. I've never heard of this concern, but if we do analyse it we get the following results. The 80% voltage point of a LiFePo4 cell is 3.42v (max charge point 3.65v) and the 20% voltage point is 2.73v (min discharge point 2.5v). Over 94% of a LiFePo4 cell's capacity is available within those two voltage points. Any chance you can do a test to confirm this?

[@knurlgnar24]

@@VinoVeritas_ They are danger areas but after more research I agree that I may have overstated the impact on this particular chemistry.

[@james10739]

Well. The battle born is a good battery but if I am doing it I'm using 280Ah cells and a bms and have a 280 Ah lithium battery for under $500

[@ricklearned1686]

That is what I did as well.

[@MrSummitville]

@@ricklearned1686 Where did you get a 12 Volt @ 280 Ah LiFePO4 4 battery with BMS for under $500? And does it come with a 10 YEAR warranty ?

[@ricklearned1686]

@@MrSummitville I bought the cells on Alibaba and had the BMS from another project. Of course there is no ten year warranty but in ten years if I only have fifty percent I would still have 140 Ahrs.

[@MrSummitville]

@@ricklearned1686 The lowest cost for Lead Acid battery is approx $1.00 per Amp-Hour at 12 Volts ( 5 - 7 years ). Adding in a $150 BMS, then your $600 battery pack is about $2.14 per Amp-Hour at 12 Volts. So, a Home-Made / DIY battery is still twice the cost. And you are assuming your cells and BMS will last 10 years ( no warranty ) ...

[@ricklearned1686]

@@MrSummitville You are correct and based on that you should buy a Pb battery. The reasons I prefer Lithium batteries is that: I only need half the Amphour capacity. Therefore the costs are closer. Lithium has little Peukerts so I actually can get more than twice the kWhs out of Lithium vs Pb. They charge more efficiently and do not have to be fully charged each night which means I need less solar and what solar I have is more available for serving my loads during the day.

[@markclark4154]

LiFePO4 batteries like to be stored at 100% SOC. NMC prefers 50% to 80%. LiFePO4 have 95% Coulombic efficiency. Lead acid around 70-80% depending on discharge rate. This is an important consideration for off grid solar.

[@knurlgnar24]

LiFePO4 batteries age rapidly if stored at 100% SOC. They age best when stored at around 50% SOC. Battery manufacturers universally recommend 50% SOC for maximum life and usually 80% SOC for standby use. Lead acid has far better than 70-80% coulombic efficiency, closer to 95% if appropriate batteries are used. All of these factors are included in the video series. Please stop spreading blatant false information.

[@tekdragon]

I really appreciated seeing a breakdown of the numbers for all the different scenarios. will you being going over the differences in "usable voltage ranges" in part 2? I know some 12 volt electronics don't operate well (or at all) below 11ish volts. also, will lithium batteries have a longer service life in scenarios when the charging solution is sometimes unable to replace the bulk of capacity used immediately? (say in a solar setup when the seasons change and you get frequent periods of cloud cover etc)

[@knurlgnar24]

Yes, I talk about some of that in part2. Based on your comment it sounds like you already have most of it covered!

[@gerrylittle6512]

I'm in need of some advise I live totally offgrid with only 400watt coming in I'm using 2 poor lead acid now a dealer I was going to buy 2 trogan t105 for $320 but he also has 2 reconditioned discovery agm batteries...which would be the wisest choice ?

[@gerrylittle6512]

He wants 150 for the agm batteries no core

[@knurlgnar24]

I would avoid any sort of reconditioned battery unless the discount is well over 50%. The T105s are probably better for you between those two. However I would encourage you to ask about the T105-RE battery instead as it only costs slightly more but will offer something like double the life in your application. It is best to get a battery designed for use in a renewable energy installation as they will offer superior service life. There are two more steps up in Trojans offerings but the -RE is the absolute base level I would purchase for an application like yours unless you're in a 'run what you brung' situation. With those flooded batteries check the water levels monthly and use pure distilled water to refill to the proper level when low. They should offer a good service life as long as you fully charge them at least once a week or so.

[@Kennephone]

Keep in mind that the batteries he's showing are the highest end ones you can get, and there are perfectly fine AGM and lithium batteries that less than $200 per kwh, they might not be as high a quality, but they will still be perfectly fine and reliable, at least if it's not being used for industrial use where every extra cycle can more than make up for the extra cost.

[@knurlgnar24]

I agree. I only have these because an industrial manufacturer threw them out.

[@jaymwales]

I’ve used a lead acid battery in my van with my solar for five years with no problem I make sure I don’t drain it more than halfway and I’ve only put water in it three times

[@donowens5883]

Do you really get a thousand ampere hours on your battery bank and it lasts a thousand hours with before it goes dead and how long will it take for a thousand Amper hour battery Bank to be fully charged on a 45 amp battery charger if they're hooked in parallel well that also determine how many amps that would take or do you have to at least have a 200 amp battery charger get some output out I know you can boost them as 80 probably in a straight line and a parallel circuit still have it at 12 volts this is 1,000 amps at 12 volts how would you get a thousand amps with 12 volts are you able to generate a thousand amps 12 volts and still be able to charge your battery Bank without over taxing the battery charger?

[@tracyrreed]

Wow. Awesome analysis! So why are Tesla building Powerwalls from a zillion little 18650 cells?

[@knurlgnar24]

Because money and politics.

[@tracyrreed]

@@lexiecrewther7038 I think knurlgnar24 has made a pretty good case that is not true. Where do you think he is on error?

[@iantheinventor8151]

Found your videos very interesting & wondered if you’d come across Lithium Titanate 🤔

[@knurlgnar24]

I have come across LTO. I have not done deep research into them but from what I know they are only practical for specialized applications. I don't consider them a good technology for stationary off-grid solar which is what this video specifically covers. For something like a hybrid vehicle things may be different.

[@gamingandvloging1117]

Love the vids. Keep them up!

[@dosomething7930]

Can you do a vid on iron nickel battery?, not much information out there. Like your vids keep it up.

[@fratermus5502]

7:45 - "empirical units" was an oddly appropriate misstatement :-)

[@knurlgnar24]

I never noticed that mistake until you pointed it out. I'd seem more witty if I didn't admit the mistake I suppose!

[@HeinzMeulke]

The costs of Lithium will rapidly fall with economies of scale. This has already started happening, it is only a matter of time. The motor industry gave it a nice jump start (yeah pun intended).

[@knurlgnar24]

I agree. At some point Lead Acid won't make sense for off grid anymore.

[@tirivaenim]

My greater question are: 1. Does lithium batteries perform better than AGM or Gel during high discharge rates? 2. If I go for Lithium is it then recommended to keep my battery at 90-95% state of charge & not go below 25% DoD? 3. Looking at prices in Africa & warranty, AGM & Gel are at maximum 2yrs, but generally at 1year, Lithium is never at 5yrs plus and truthfully getting a manufacturer to honor these is clutching at straws. 4. Price of lithium (Pylontech US2500), is about US$1.250 & 200ah x 4 batteries is US$1,400 (which give me circa 200ah in a 24v system at 50% discharge). That extra $150 is something & excludes labor & installation which is another US$240. 5. Making sure batteries are correctly installed in series & parallel to ensure good balancing during charging and discharging is another issue. Your 2-cents would be greatly appreciated.

[@knurlgnar24]

1. Depends on the context. Internal resistance is lower with Lithium chemistries and so it has the reputation of performing better at high discharge currents. In reality lead acid performs better due to no limit to discharge rate, and down to about 80% DOD lead acid is not internal resistance limited in a a properly sized install. 2. Lithium will last longest if charge is kept around 50% state of charge. This is impractical so ideally you would keep the battery at about 80% state of charge for maximum life. This is commonly done in industrial applications but is difficult to accomplish reliably in consumer applications. 3. Ignore warranties. Look for a quality product. 4 and 5. I think these topics are too complicated for a comment reply.

[@tirivaenim]

@@knurlgnar24 much appreciated for the response

[@phillean]

Very useful, thanks.

[@SearchFT]

We need a Neil in every school 😀

[@subigirlawd_7307]

Hmmm what about heavy loads? Which one would be better... If I go outside on a winter cold night with a hair dryer full blast running on a cheap ebay converter 😏 straight to the battery, which type of battery would get less damaged? I think the acid battery, but I'm only guessing... 😉 (not including any battery protection)

[@knurlgnar24]

Part2 will have more info on this. Not sure how to answer the question adequately in a single paragraph.

[@subigirlawd_7307]

@@lexiecrewther7038 spoilers 😣 was waiting for part 2

[@subigirlawd_7307]

@@lexiecrewther7038 The cold temperatures was referring to the coils in the hairdryer getting up to temp on a crap amp hungry AC converter ..but yes add that too

[@MrSummitville]

@@subigirlawd_7307 Batteries do not get "damaged". Batteries are a consumable. Do you damage your tires by driving your car? No, they are a consumable ...

[@subigirlawd_7307]

@@MrSummitville We are no talking about normal or average use, we are talking about extreme abuse.. New tires on a car yeah but if I'm doing donuts, accelerating, sudden stops and hitting the curbs ect, I will damage the tires 😘

[@recharge5620]

FYI lead acid batteries can be used for decades if you know how to recondition them. I know guys using the same deep cycle marine batteries since the late 80s.

[@knurlgnar24]

Not all damage/age can be reversed, but I agree that most lead acid batteries are recycled before they need to be.

[@SupremeRuleroftheWorld]

great subject, but i see some misconceptions in the lithium calucations/opinions already. context/disclaimer: i run a battery company and i have spent litteral thousands in measuring equipment, tooling and manhours. the short of my point is this: if you take basically and high end 18650 cell and do the "recommended" (at least in your version) cycle of 30% while the top 20 and bottom 20% are not used then you can expect a cycle life of 20.000 cycles or more. i dont know how much more because i stopped my testing at the 20k mark. this means you get 50+ YEARS from a lithium battery without losing much capacity. for this reason you can go WAY further in the DOD and you dont need so many amphours. my testing indicated that you can use top and bottom 10% of no-go area with a 70% DOD (so you are using about 60% of the actual capacity EVERY DAY) and get 25 YEARS of cycle life. and with basically perfect/non existant peukert effect. fun fact: this matches also what tesla is doing in their batteries. its clear you are an expert on lead acid, just not in lithium. not a problem. but please ask actual people that work with and sell them and have to warranty their products. ps: turn the volume of your intro down, its WAY too loud. and check your audio, for some reason your video sounds like its recorded at the beach with a fake wall.

[@knurlgnar24]

Arbitrarily large cycle life numbers can be obtained with lithium - I have no disagreement there. My disagreement comes from that huge cycle number being of no use in a real-world application. Calendar life in application is all that matters when it comes to life duration and here time induced degradation dominates in the context this video covers. Have you also performed ALT on those cells at various temperatures/humidities? Have you generated weibull plots of each of them to determine acceptable failure rates under various stress conditions to determine acceptable reliability standards? I have yet to find any information that adequately supports a claim of much over a 10 year life on a lithium battery in this type of application. This is partially due to insufficient time to get field data, but also due to insufficient test data available to the public. The Sony's and Panasonic's of the world have this info locked up tighter than a dutch wallet.

[@SupremeRuleroftheWorld]

@@knurlgnar24 i have done quite some testing that is conservative and less conservative. i found that with the cells we generally use for stationary and RV usage that a 4.1V float voltage and 3.2V bottom limit (wich equates to about 85% usable capacity under moderate load with the cells we generally use) you can get 8000~10.000 cycles before you get down to the 70% capacity mark. the battery is still very usable at this point. just a lower capacity. it can still provide huge currents unlike SLA. the major damage comes from fast charging and discharing. but with stationary usage the battery is so big that you cant drain it fast enough and with solar cant charge it fast enough to do real damage. humidity is also not a factor in this. temperature is a factor in capacity and internal resistance. but again:: that is not a factor in stationary applications. at worst you can include pack heaters to keep the cells at 10~15C for example to mitigate low temperature weather un unheated/protected locations. once you get into the 10kWh and bigger the actual specs of the cells dont really matter. the load per cell is so stupidly low that they "live" so comfortably that wear is not really a thing. this is why i have no issues giving 15 years capacity warranty on some of my products. and yes, i have lots of data for this but for competition sake i dont give the datasets for this. i can give you my conclusions and practices for effective and economical building of such batteries. and for the record on that lithium battery you brought as an example: its a fucking ripoff. its is litteraly the worst example of lithium based batteries you can get. i would like to see you give a real world battery setup calulation. but not with those stupid lithium batteries, those are just dumb, nobody buys them. example: i sell a basic 10kWh (usable capacity) battery bank at 48V for about 5500 euro's. wich is basically on par with a tesla powerwall but without the tesla bullshit.

[@SupremeRuleroftheWorld]

@@lexiecrewther7038 that is a whole different type of battery.

[@MrSummitville]

@@SupremeRuleroftheWorld Did you "AGE" the battery? What will a severely used battery produce after 10 YEARS of aging and 3,650 cycles? You do not know ...

[@paulsingh9043]

🤔… very interesting!, finally !, somebody who isn’t bullshitting , well done sir , your a legend!!!👍🏾

[@knurlgnar24]

Thank you! I'm glad you found this information useful.