My worst B-Grade cells vs. Certified Automotive Grade in a 100%-0% 200Amp Discharge Test. Surprised?
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- Опубликовано: 26 мар 2023
- To bring the discussion of it is worth buying #certified automotive grade cells over storage grade (#b-grade) cells to an end, once and for all... here is the 200A high power discharge test: EVE LF280K certified cells in comparison to the fake 'Hithium' cells. The best I have vs the worst I have!
So far, we could only test certified cells with a maximum current of 40A and compare them to not certified cells, so called B-grade or storage grade cells.
The results did not show any advantage for the more expensive certified cells, in fact, some of the B-grade cells tested actually better...
Now, some say the certified cells are a lot better with high amp discharge, holding the voltage better, delivering more energy than other cells.
Well, without further to-do, here is the ultimate 200A+ full power discharge test from 100%SOC down to 0%SOC and my final #verdict and thoughts about certified automotive grade batteries...
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The JBD 250A Smart BMS with 5A active balancer (Muller Energy Edition):
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When the JK-BMS goes up in smoke because it cannot handle 170A:
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Testing certified cells vs b-grade cells. Worth to spend the extra money?
• BEST cell to buy - Tes...
All results form this test (and more):
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I think you single handedly raised the price of B grade cells worldwide Andy 😆 Great and informative test 🤠👍
Such a test might also cause the decrease in price of automotive grade cells.
Yeah, that may cause a price shift now 😂
As long as companies send me these certified cells to test, I have to test! 😁 I just don't get any results near what has been claimed.
@@pbasista sorry but no, certified buyers have different priories. The cost of techs to go and manage grade B would be too high.
@@sfkenergy _Some_ buyers used to acquire certified cells without any reason other than seeing unverified claims online.
Great testing, as many customers experience, real good B-mark cells works well for their ESS systems if the voltage are well balanced.
Andy - youre simply the best!!! 😍🌅🔋
Thanks Andy!
great video - perfect mixture of scientific method, documentation, experimentation, plus humor
Thank you!
Awesome Andy!
This is great community support.
Fun test. Good on you, Andy.
Thanks 👍
Great video - Thank you Andy👍👍
Thanks , Ingo.
Thank you for the addition of awg sizes: )
Well done Andy.
Thank you😊
Looking forward to this. Thanks.
Nice one Andy. Very helpful video to knowledge and pocket 🤣🤣
Thanks a lot.
AMAZING! :-D This is by far the most interesting test in the past few months I have seen, on EVERY channel I've subscribed. Thank you very much! I still find it hard to believe, even after seeing your video, as AFAIK, exactly that test, close to 1C load, should have shown the real difference with certified EV and storage grade cells. And you also mentioned you used your _worst_ batteries as comparison, so it just can't be pure luck - not with that many batteries from multiple sources - or have they all been hand picked for you? :) The only thing that could explain the results. Amazing results in any case, keep up the good work, I love your style!
Thanks so much, Lasse. Very kind comment and feedback 😊
Well, if they have handpicked these cells for me, they did a terrible job as they are not better than my worst cells I have 😂
Great test, thank you for taking the time to do this. You just saved us all a bunch of money. I guess the only test left would be total cycles, does one last longer than the other.
Good luck testing that though. Even if you were to cycle them daily, you're talking over 10 years...
@@upnorthandpersonal It was kind of a joke, I realize that it would take some time.
@@joeyoutdoors Yeah, so was my reply actually. This kind of humor doesn't translate well in a comment on the internet...
@@upnorthandpersonal As more of these cells are scaled, the prices will continue to fall. even if the B cells last 5 to 7 years to 80% capacity you will most likely be able to replace them with new better cells cheaper than all in Grade A cells from the start. So this test was very valuable, as the value proposition is exposed with a pretty darn accurate set of tests.
@@joeyoutdoors I reckon mine will be out of cycles when I am about 120 years old. That really concerns me. 😅
great test 👍
Another great comparison and test
Thank you.
What a Great Test!! Love it!!!
Thanks, Joe. Inspired by your video ;)
Epic moment with the "Bang"😂😂😂.. watching every video of yours👍👍
The final word on certified storage grade cells . Thanks for you work on this one , lots of amps and hours and ah's .
Yep, exactly, We can hopefully get over this certified stuff now and keep building awesome batteries, regardless what people have.
@@OffGridGarageAustralia Yes , personally I'm proud to be a grade B clown .
Very interesting Video Andy!
The BMS part was my favourite! 😉
The BMS is amazing! I really love it. A 16S version with 150A would be a winner!
Yes we need a 16s 150a ! I will take 3 or 4 when you make them .
@@onthelake9554 we're working on a 4s-16s version. It will have active balancing on board and the firmware will in all likelihood be opensource so that users can change it in any way they see it.
The heating connector can then be reprogrammed to be used independantly of the main MOSFETs on the board. Not just for heating but for any 5-10A load you want.
It will also have some other features and will be ESP32 based so you can basically run a lot of the Arduino applications.
It will also have Bluetooth and Wifi and potentially a micro-SD slot, in case people want to use it for data logging.
@@mullerenergy This is great news , I will be a customer for sure . And thank you for supporting Andy !
@@mullerenergy Nice! Cant wait to see this BMS on Andy tests. Opensourse fimware is qreat idea and Im sure that people will love it. On this way your product can work exactly as customer want and need. Opposite for locking bms setting and weird thing like this. Are you shipping worlwide? (Europe). Thank you.
Yet another excellent review and helped to make my decision on purchasing A or B Eve 280ah cells
I had to do it as I wanted to know myself.
Heya, that's an inpressive test well done
Very interesting! Thank you Andy for testing this for all of us out here on the Interwebs, now we really know and can discard all previous assumptions and marketing material / hype.
Thanks for your assistance with this test. I'll test the busbars as well at some stage and see if there is a difference.
The result was unexpected for me. I had thought, the cert cells are holding up a bit better.
@@OffGridGarageAustralia me too, but as they say, hold strong opinions but don't hold them strongly. Let the evidence speak for itself.
@Off-Grid Garage Don't you still see the likelihood of getting a bad/under-performing cell or two when buying 16 cells Grade B cells that could affect the battery performance much more than this test shows? Don't you think that theres a matter of 'Luck of the draw' when ordering Grade B cells or perhaps the production process has matured in the past couple years that makes it less likely to get an underperforming cell?
@@580guru I used to order extra cells to cover that likelihood. Buying the certified grade cells takes away that need. But you are right, there is definitely more to be considered here and I am sure we will get to the bottom of it over time.
@@580guru Well, with my Battery1.0, we had a couple of bad cells in one batch and the whole system is only as good as these cells now. But, you know, 10Ah more or less really don't make a big difference. As long as these cells don't degrade much faster than all the others, I'm not too concerned.
With all the cells I bought, I always had some with less capacity and some with more capacity as rated. And as we can see, even the certified cells are not much better.
I would not recommend ordering cells from AliExpress though but go through 'reliable' sources like QSO, Gobelpower or Eel for example. At least you have a person to talk to if something is wrong.
My girlfriend doesn't understand why I have to calibrate my solar panel alignment tool all the time
You have to share and teach her. She will love it 😄
@@OffGridGarageAustralia Yep, perfect alignment is essential! 👍
This not very offen happening!!!!!
Shure your batteryes are serify right??
Try this at VW batteryes and you crash this test
Thanks Andy 👍
No problem 👍
I think one of the more interesting lessons is that the mechanical aspects of setting this up were the bigger challenge. And in that aspect the certified cells seemed harder to hook up successfully.
Andy, perfect as usually 🎉
these cells are certified for a current of 1c, and although this does not matter for our segment, I think it would be fair to perform a test with a current of 1c, 280 amperes in our case. most likely we will see the difference. and this will forever close the question of the difference between cells that passed the test and did not pass the test. 1с current and its behavior can be a reason....
also a voltage drop lower than the cell rating can be decisive for the test result. the difference between the voltage curves at the beginning of the discharge is visible even on your test, while the cells do not fall below 3.2 volts. but at a current of 1s, the difference will most likely be more significant. for us, of course, this does not matter, but for building a car battery, voltage drop is as significant a factor as capacity.
Thank you. I really don't think we will see any difference at 1C. If there would be an advantage of the cert cells we would see already a small gain in the 200A test. But nothing. There is no threshold where the cells all of the sudden get better once this is passed. And, as you said, if there is a small advantage at 1C, it does not matter. Not even when building an EV.
And, I really don't have equipment to run such high currents. That would mean a big upgrade to busbars, cables and inverters.
@@OffGridGarageAustralia welllll, 1C discharge causes the cells to heat up more internally, increasing the internal resistance and maybe affecting ion kinetics somehow. First see then believe. Maybe you are right maybe not. But yeah maybe not so relevant for storage. Thanks! Very nice video.
Where did you buy these from and the 250A bms? Nice test!
Awesome Andy, …. As usual, very VERY interesting!
(You get excited when you see 150A.
I get really excited when I see 43 or sometimes even 45A 😂)
That’s a really fabulous result for the “dodgy” cells - I just absolutely LOVE these batteries.
BTW Also : How does your FLIR camera go? Mine is only 11 months old, and I’m lucky to get 3 minutes out of the battery- not impressed! I can charge it one day and it’s always flat next day. 👎👎 Bloody ridiculous for an expensive piece of gear.
Thanks Dave. The dodgy Hithium cells are still holding up great💪
No problem with my FLIR so far. I keep the battery around the half full mark all the time (you check in the app).
I'm sure you just replace the battery but still very annoying. Send them an email!
Excellent job Andy, I have been waiting for this test & results, & they came in as expected & confirms it for me, we are not getting a premium battery for the premium price, B grade wins. Thanks
Yep, B-grade wins.
Hi Andy it would be interesting to show the volt drop in your cables. To and from the inverter and actual power loss in the cables. From the battery packs . As this is something I find that tends to be overlooked.
Hi Andy, and thanks again for this video.. really good test.. 😁
We can say that your B grades are good, very good even! but unfortunately this is not always the case...
No, it's not, I know that. I have some other cells from Battery1.0 which we could test as well. We know, they have a lower capacity. But we also know they would handle the 200A just fine, just not as long as the cert cells. If that is the only difference, there is still no reason to buy cert cells.
Catching you up .... as we are heading to Summer now today was my first 100A of the year - had seen 90 but hit the max of the 100A MPPT today.
good testing :)
Nice! Let the sun shine🌞
dying laughing, metal roof expansion noises get me sometimes too.
haha andy in aus, youre videos is top notch for us nerds….😅😅
The thing is to find that thing that makes life as good as it can be.
Im into fishing BUT I also bring a caravan and want to stay off grid for as long as possible on the fishing grounds, best to you there in aus!!!
Also highly regards to you personally, better presenter of your videos would be hard to find😂😂
Nice fair test Andy! Are these isolated bus bars with nice balancer connector somewhere sold separately? Grtz from not so sunny Netherlands
Thanks Ivo. I don't think they sell them separately. Others have asked as well, so there might be a market for them...
Three years in with my cells - definitely not EV grade, and no issues. I want to add more. Maybe I'll order 16x 304Ah cells next; that would bring the total to 75kWh or so.
Have you noticed any suppliers providing 304's from Europe or do you prefer directly from China?
@@KossuJahvetti I prefer directly from China. Some Chinese suppliers have stock in the EU though, so you might ask them. Just avoid Aliexpress.
75KWH should hold you for a day or so...😊.
@@Sanwizard1 Yeah :) About 12 days worst case scenario...
Do you need more storage or rather more production?
Excellent channel. Question: is it advisable to use Ultra Capacitors in between lifep04 batteries and the inverter to offset hard draws to prevent damage to the cells or prolong them?
I am not an electrical engineer. But, if I understand correctly, lithium batteries (and most others) can only be majorly impacted by discharge if they experience far more than rated current and for continuous, extended periods. So, as long as you keep your batteries properly balanced prior to discharge, it is unlikely you will have any major, extended issues with cell imbalance or uneven discharge, which would pose the biggest danger in peak draw scenarios. Make sure your inverter / DC loads are at least somewhat properly sized for the battery, and you probably won't get much, if any benefits from supercaps. Inverters themselves are usually equipped with large capacitors at the source as well, maybe for just that purpose. Just my two cents. It is definitely an interesting idea, though, and might work in very specific applications.
Great Test Andy, you show again great information about LifePo Cells, but i never get grade B cells from Shenzhen Qishou Technology Limited, they are everytime fine and grade A
Yeah, so far, I cannot complain either. I had some 'less optimal' cells from Basen at the beginning but they are still working well and have no issues.
I had a cell with a hot terminal too. Tried everything under the sun. Cleaning, sandpaper, emery cloth, different bars, torque. Finally ordered some MG Chemicals black carbon grease. Worked perfectly! I'd love to see a test of this sometime!
Interesting…
Luckily the most that many of us ever pull with solar applications will be about 0.1 or 0.15C.
I've got this crease here as well, can do a test and see if it fixes it...
Das wäre toll. Wie heißt die schwarze kohlenstoffpaste auf deutsch?
@bluetrepidation if you use aluminum bus bars you can try to send them very gently but do not wipe of the dust in the end. I have those LF280K with big terminals and what I've found if you leave the dust (basically fine grained aluminum) connection resistance is so low that my YR1050 can not even measure it. But if I wipe everything with alcohol and reconnect, it becomes like resistance of 1 or 2 cells. I think that aluminum dust might be acting like that paste, it covers every hole and creates more paths for electicity.
@@AlexanderBartash that is a very interesting experience you're sharing here. Thanks a lot for that.
The roof expansion was scary lol.
Super nifty test! Are the certified batteries really certified? Is there some barcode or certificate enclosed with the batteries to prove this?
I just realised there is additional paperwork attached to the other side of the box. It's from EVE directly. I haven't read it yet so will provide these information later.
Ohhhh no.... Activate the subtitles for Brazilian Portuguese, always accompany you here you are a great reference for me in my Solar projects
There is nothing to add. Great test. 🖖🖖🖖
I think we have tested everything now, right? Results are clear.
@@OffGridGarageAustralia I think yes. It's a really great test.
Maybe it is not directly related to this topic, but I would be interested in one thing. How accurate is the measurement (performance, power, voltage, current, etc...) using Banana Pi with Venus OS + JK BMS if you compare it to the Victron Smartchunt.
You have inspired me very much and thanks to you I embark on a similar project. I like your sense of precision and a sense of detail.
Thanks for all the videos. 😉
@@Slavomir-1977 Uh, that is hard to say. So far I could see a quite large difference between the Pi and the JK in terms of SOC. Which is one correct, is hard to tell though. Because I have so many different BMSes I made the Victron shunt my point of truth. For my installation, it is no question to use the shunt as I have several batteries in parallel.
The difference in the curve at the end is probably due to dissimilar capacities, those EV cells has some amount of difference in IR probably due to better terminals and slightly better binning but aren't match very well which is worse.
Hallo Andy, thanks for that test.
It's still a big question for me what kind of miracle makes the difference to certify a cell or not ...
Well, there is no difference apparently. Not sure what else we could test to show a significant difference.🤷♂️
Your certified cells have All the boxes filled in. Ah when manufactured. Why does SFK omit that???? Great video. You can never overcalibrate
Doesn’t SFK say that the way the measurement is done at the factory is it’s watt hours measured and then they just divide that by 3.2 to get the Ah number? They don’t test for Ah. I think that’s what SFK said.
I wasn’t too sure about the guy at first but all of his points are absolutely valid and the actual science behind it is proven. Typically these Grade B cells have an IR that’s way too high to meet spec and that’s why you see they perform not so well when major current is applied.
We just don’t see too many Grade G(arbage) cells anymore. There’s too many decent sellers out there for the scumbags who buy the dumpster diver picks from EVE/CATAL etc
I think to calculate the energy by using a fixed voltage of 3.2V is totally wrong. The voltage is dynamic and can only be measured by a tester which is constantly measuring it.
Are you going to trust your lying eyes or use our new math that favors us?
Great test! It appears as though the grading of the cells is a marketing trick. The only difference is price.
That's what I think too.
You're not using the JK BMS now? I think it was a JK-B2A24S20P 200A unit? Have you tried the TDT sold by Shenzhen Tuodatong Electronics?
NICE!😁
Real problem with B grade is when you discharge them above 0.5c (in worst case) when they drop voltage and take more amps. Then you can find that have slightly less capacity. On a car that’s slower and less range but houses don’t move.. Aside that they last what is stated. No prob at all.
They seemed slightly worse than the fake ones... Very interesting.
Man the ev cells look perfect
They do look good!
Docan Power told me to use 7 Nm torque for the EVE LF280K with welded steel studs. I don't see a problem with that, but you want all threads in the nut to be in contact with the stud threads. With your double thick bus bars the stud isn't fully into the nut.
Hello! Please tell me, I want to assemble EVE 105ah batteries, is it possible to place the batteries with the contacts facing the face (horizontally on the edge of the battery), and not up, as is the case in most cases? I read that lefepo4 can be placed in any position, just not with the contacts down, but I would like to hear your opinion! Will this interfere with the normal operation of the batteries?
Where can I acquire a battery shelf like the one your using. I want to build a large bank also.
For automotive use I would prefer a Bus Bar with a bit of give/flexibility Andy - On my RV camper I use some 300amp arched flexible bus bars that are 30 stacked copper laminates from Aliexpress that will cope with road vibrations and temperature change
Or, you have to fixate the cells so they don't move any more. Compression 😉
@@OffGridGarageAustralia Compressed cells still expand & contract with temperature - Trees that bend in the wind last longest : )
I think the current meta is something something big flat terminal is not welded on straight. The busbar is big, flat and stronk- it may be unable to lay flat on the surface if it's angled.
Made an eve 304 grade a order recently (at least the importer says they get them from eve) and those come with flexible busbars.
The angled terminals were in couple videos last year. I would assume they have figured out how to make them actually flat by this time.
Great test video. I like these massive terminals and massive basbars with two screws on each side to give a large contact area, they will get a lot lower heat and probably be a lot more expensive. But for normal use (not ultimate 200A test) it will be probably over dimensioned, I would say, so for normal use those classic welded M6 screws on the battery cell terminal will be fully sufficient, is that right?
Well, you will be surprised that it is the opposite. The terminals of the cert cells got much warmer than of the b-grade cells. The tiny contact area of the welded studs (b-grade) are perfect for 200A+ and don't heat up much. The force really concentrates on this small area and resistance is super low.
As you have seen in the video, I had issues to get the resistance of the large contact area down (cert cells) while the studs on the other battery works well with 200A+ and only 4Nm of torque.
See also this test video about the welded studs if you haven't seen it yet: ruclips.net/video/VPQvs-2YYzA/видео.html
@Off-Grid Garage Some of these double screw terminals were anodised in the past on the LF280K.
Maybe that's the issue that creates the extra resistance because all the current then needs to travel through the bolt only?
Maybe this is also the "old" cell in the pack? Strange there is a year difference between these kind of quality cells.
I'm expecting 16 cells next week, same grade and with the same terminals. Can't wait to check them out!
@@OffGridGarageAustralia Great test (as always!) and a surprising outcome!
I hope this is favourable as I've just ordered a whole load of EVE lf280k grade Bs😬
Good choice, I would say.
Andy, have you ever tested the iBMS build by TDT? They claim it is compatible with a load of inverters and is has a strong balancing option, compared with the JiKong BMS.
Yeah, seen that. One of the many brand which stamp their name onto the same sort of BMS. It seems they are using a passive balancer with 0.1A only though.
Hey Andy,
I have a great experiment for you and money making product. 300Ah 8s with compatible super capacitor pack for, if and when a battery bank might shut down above 21 volts, before inverters and charge controllers can safely shut down on their own at 21-22 volts.
All of the UPS inverters /and solar charge controllers I have seen, warn to never disconnect battery when in use".
Considering all these lifepo4 banks can shut down from only one cell being low or high. Something that would hold that high shutdown voltage and slowly discharge to reach the 10.5 21 volts would be worth money. These are already sold for car audio but I don't see nothing for big battery banks.
No Bueno - every time I come to this channel I feel like I get hit in the head with a hammer. All the my concerns, speculation, and pontificating, and it turns out there is no difference.
Although the fact that that bus bar was getting so hot still makes me wonder if the test failed in some way because of a bad inspection
So how/where do I buy them? I'm in WA and struggling to find a local supplier.
Great video Andy.....
I would love to do my own charge and discharge tests but the cells I've ordered through AliExpress have not arrived and the seller won't even read our emails for requesting delivery information so we've now requested a refund......
Maybe you could do a short video on how to purchase correctly through Ali Express as there's often limited information on the products and obtaining other useful information is quite difficult.....
Thanks Dale.
Oh, that's not good. Hopefully you will get your money back or the cells delivered.
I made a few videos about ordering from China but that was through Alibaba directly.
I would not recommend anyone to order batteries through AliExpress as there seem to be a lot of scammers on this plattform and batteries never get delivered or are of very bad quality. But I also heard positive experiences...
If AliExpress is not helping, you can always get your money back through PayPal or your credit card institute.
@@OffGridGarageAustralia Andy... one last question before I wrap this up.....
Do they make 320 amp hour Cells?
Because if they do not make 350 amp hour Cells I will not purchase any more....as that would clearly be a scammer !
@@daler2577 Apparently CATL makes 320Ah cells. I'm not aware of anyone else...
Hi Andy, I sent my certified double threaded terminal EVE grade As back, the threads were oversize and slack helicoil inserts, felt very soft on torque test, there were burrs on the countersinks and they looked little wonky side to side not giving flat contacts across the two cells, could this be the cause of your heat?
They tested low, mid 270s My first order was damaged. Got full refunds from a uk supplier no problem and went grade B.
My EVE etched grade B are very strong mid 280s with no horrible voltage sag. A tiny bit of bloating with no damage.
I am very very happy!
And saved a fortune! I am testing the last box of 32 😂
Cheers
Gaz T
Oh, wow, Gaz, you're going full in! Another 32 to test...
I really like the welded studs we have tested before. The tiny contact area is perfect for very low resistance.
@@OffGridGarageAustralia Yeah no half measures Andy!
Though I am fed up with the tests ending at 3-4AM and I have the fear of my old lap top freezing up and not saving, I have lost 2 results digitally😭😭😭.
I never tested all 32 grade As, just half a dozen or so before I was sick of the sight of them and enough was enough for them to go bye bye.
Cheers dude 😎
After seeing this, I'll be checking the bus bars on the really cheap 8s 100Ah pack I have. I thought the cells were just miss matched. that would be nice if it works.
Hi Andy what is your opinion on the the welded double bolt terminals on the automotive cell ? Would you say they are better or worse that the welded single stud ? I saw on one of your earlier videos you stripped the thread on one of the cells that had to have the stud fitter first and you had the repair it , would this double terminal suffer from the same problem when using bolts ?
I don't like the double terminals and had issues with them in the Frankenstein battery. If they are not 10000% levelled, the busbar have to bend to connect to the next battery. Otherwise you end up with a tiny gap (visible with a torch).
The single welded studs are great as they provide a fairly small contact area where the pressure of your set torque applies to. Perfect for 200A+ with standard copper busbars as tested.
Stripping terminals was from the time when the batteries had only two M6 holes in the top and the depth of the thread was close to 6mm only. More than 5Nm of torques applied, was sometimes all it needed to strip out the whole thread.
@@OffGridGarageAustralia Thanks Andy , that is great help , I though with the extra surface area they might have been better . I live in the UK and a company called Fogstar does the Seplos Manson and it has the Grade A EVE LF280K cells and I didn't know if the terminals were better . Do you know if all A Grade cells have this terminal or is it just what the middle man puts on . The price fogstar is asking is not bad and if ordering from China and the cells are " not good " it can be hard work sorting it out with the supplier .
What is the price difference?
Maybe it doesn't make a difference in storage applications, when you are still under 1C of current but I've heard in some situations in a EV they can co over 1C of dischargecurrent mybe there would be a diffenrence.
Anyway nice to know that for the purbose of a stationary installatin at home it doesn't seem to make any difference. 😁
Thanks for the great comparrisson.
I still use my definitely used cells a spammer sold me. They still do their job without me noticing any problems. The JK-bms keeps them balanced and that's it. In practice you will never notice a difference between certified and non-certified cells in a PV plant.
That's what I think too!
I finally made 304ah battery box out of eve 304 cells, I ordered 280k but they sent me these cells to Melbourne by mistake. I used JK BMS as per your instructions Andy in your older video. I don’t know If I was ripped off by getting 304 instead of 280k.
Does not sound like a rip-off to me 😊 More like a free upgrade!
Glad to see these tests. I was planning to use these cells for an EV conversion, but I was wondering how they would handle a continuious 100-200 amp discharge with 300A bursts. Seems like it will work
Very cool project. What car are you converting?
@@OffGridGarageAustralia I have a few cars. I want to do the hyper9 AC motor into my old 4wd 1986 Subaru XT. With a smaller battery for 50-60mile city driving for the spouses commute (currently a cyclist).
Then for me I haven't decided if I will convert my poorly running 1993 Chevrolet corvette with a warp9/warp11. Or Possibly building myself a custom rat rod like pickup truck with dual warp11s and direct drive and mounting a pretty massive pack of 144v and multiple cells in parallel for 1000+ amps of peak power for a fun sports truck sort of vibe.
I have build a few muscle cars and turbo imports that i currently drive, but thinking gas powered days are fastly ending soon.
I just converted my entire house to off-grid solar with grid backup last summer by myself and with help for all the info in your videos, so im ready for another project.
@@HellTriX That sounds awesome. I wish I had such capacities as well to do such projects. Great!
Very interesting tests! Recently installed 280k cells (144V pack) in an EV conversion (Land Rover Series 2a). Currently in the testing phase and 20 kW (0.5 C) continuous seems to work fine. Max amps set in the bms is 1C.
@@inonyx You gonna do some youtube videos? Would love to see how it is working out. I planned to do 144v pack with 280ah cells with 3-4 packs in parallel so it could handle 1000-1500Amp bursts. 4 packs in parallel would be 1120 amps at 1C and at that power you won't be able to do 1C discharge very long due to speed increase :)
Hmm I wonder if you put the battery under stress of a moving vehicle and add some sort of vibration to the equation from my understanding is the reason for the automotive grade cert its not so much that it is different in quality but in how it handels the stress of the road
So if you battery is not snugged up and tight it will move more and rub more witch in turn will cause a failure in other ways such as an explosion
Andy are you planning to test the V3 of the LF280K, they increased the cycles to 8000 and the price drop 40%, terminal now is octagon.
If I get them at some stage, yes, I will test them. But it will be a boring test. Nothing really new to show...
The capacity increased 20Ah and comparing the price from 1 year ago dropped 40%@@OffGridGarageAustralia
Thank you Andy for this test :)
However I recently bought 8 EVE LF 280K cells from an Alibaba seller and I'm a little dissapointed.
I started my discharge test with the cells top balanced at 3.5V. After discharging only 245 Ah the cells voltage varied alot, more than 400 mV, with the lowest cell reaching 2.75 V.
I stopped the test there, I think some celIs have lower capacity than others and I won't get more than 250 Ah out of my pack.
Am I missing something? Is there a posibility that the sellers know who you are and send you better cells?
I tried to add a link to some JK BMS screenshots but the comment is deleted 🙂
Yeah, no links in the comments unfortunately.
Test some of the cells individually to see if the capacity differs.
Well, if they cherry pick cells for me, they do a miserable job: damaged, scratched, different capacity, Ri not matched, fake barcodes, bulged...
@@OffGridGarageAustralia You can ask some friend to place the next order 😂
I don't have the equipment and time to test cells individually, but I'm sure those are lower capacity because when recharging they are top balanced again. I will live with that 🙂
My point is that some may buy certified EV cells is to avoid such loses, since I'm not the only one experiencing this.
If it's worth it or not, it depends from project to project I guess.
I am guessing that at say 5 years use the certified cells may have more capacity. Perhaps the calendar degradation might be slower. Is anybody monitoring this? Will said he hammered the batteries and he considered it was the calendar loss of capacity rather than usage that defined life cycles. But would the certified have better performance over life cycle? Anybody a view on this (or data)?
All very speculative. I mean first we were told cert cell are better, I tested and they were the same as other batteries. Then people said, they are better under high load and current. Nope, neither... Now we're coming up with this long term guess, that they might be better after a few years... are we looking for excuses to pay a higher price for something which does not exist maybe?
This was fun to see, but a test I'd like to see (which is really hard to set up) is how these cells age. Sure they look close when they each have only a handful of cycles on them, but what about 1,000 - 5,000 cycles? Do the automotive grade cells hold up better over time? Do those buying B-grade think they are getting a great deal, but then only get half the life out of them? Probably need a pack of each and just have them take turns charging-discharging to each other. Don't need to go max cycle, anything 80+% DOD would be fine.
An impossible test to conduct. It would take years to get a result. Usually, manufacturers do such testing for 6 months or so and then extrapolate the data. Same as car manufacturers do for how long the engine will last.
The voltage rippling at 16:16 is due to the ADC not having a high enough resolution for your zoom level, it has nothing to do with the load as your load is stable.
As for the comparison... what about cycle count?!
Also if you go to EVE direct, you can (like I did) negotiate very close to grade B pricing for certified grade A cells, you just have to stand your ground with the pricing you're looking for. There is no real reason to buy Grade B from a third party seller when the price difference is a < $10-20/cell.
without any experience. my mind says that if you do a test of those two packs again after the certified pack makes some more cycles . you get even more similar curve!!! and my mind says that it has to do with the overtime usage and they are going to have better discharge curves at the end after theyt make some more cycles if they re new and no used !!! . keep up and thanks for the content
Well, both battery packs were new. I have compared a lot of cells but could never find a difference of used cells to brand new ones.
This is another claim, I guess, that cells need a few cycles to settle in and either go up or down in capacity and energy. If it is really the case, it must be minimal so we cannot see it with our test methods.
I have been under the impression that the automotive grade cells are rated for a higher discharge current? I've read of some 304 ah cells rated for a discharge current of up to 600 amp! I wondered if this was true...
Nothing different in the specs and behaviour of these cells between certified and storage grade batteries.
If cells have dents in them but no puncture holes are they still safe to use I bought some scratch and dent 277ah cells with dents in the casing on some of them..
Yes, still OK if not dented heavily. I use two cells with dented corners and they work fine.
@@OffGridGarageAustralia ok thanks
Thought for the day - Any cells that have sat on the shelf for >1yr could they be considered Grade B due to lack of use since they were manufactured?
If they were stored at around 50%SOC, there is no problem with that.
18 months is what EVE and REPT do, after that they are sold as grade B. This usually happens because of an odd ball left over supply amount.
There's 1 massive difference between certified and none certified..........the cost of purchase💰
Around 50% more for cert cells...
23:00 If all cells get "flushed" by the same current, why should any resistance in the terminal connection change the load they get? If the internal resistance is the same (nearly) they should charge to the same voltage. Or do I understand electric engineering wrong?
The BMS measures the cell voltages and if one cell measures lower because of a bad connection, this would determine the trigger for the BMS to turn off once the measured voltage is down to 2.5V. The cell itself will still be at the same SOC as the other once (assuming they all have the same capacity). The higher bus bar to terminal resistance would prematurely end the test with a lower result.
Very interesting. My 16s pack of LF280k from Basen (batteries from end of 2021) ran a full season without any issues, delivers only 255Ah from 3.45V to 2.9V. Probably need to check the crimping and temperatures?
Andy tests from 3.65v down to 2.5v. 3.45 to 3.65 is not much at all and 2.9 down to 2.5 will get you another 4 to 5 amps. So still ends up a bit low, what were they back in 2021?
@@glencooke494 once at the beginning, I could reach 262Ah, but only once.
@@glencooke494 in summer I will do a test from 3.65 to 2.5V but it is a bit annoying to change the settings in the Multiplus, as the system is running without issues (never change a running system xD)
I would leave it running as it is. Are the cells top balancing OK?
Even if you have one cell with a lower capacity, there is not much you can do anyway.
@@OffGridGarageAustralia top balancing with the JK BMS works well. Thank you for your answer!
Yes video👍 ⚡🔌🔋💡
assuming price equity is the dual post variant mechanically better ?
No, it's the same terminal underneath. They either weld a stud onto it or the double thread terminal. The stud version is heaps better.
@@OffGridGarageAustralia Thanks Andy and cheers from Italy 🙂
Bonsoir :) The certification relates probably to the repeatability of the large sample. You are guaranteed that if you buy 30 of them, you'll get the same discharge performance throughout the sample, within some small error level. For the others... You were probably lucky :)
Well, that is just another guess though that they might be better in the future. There is no proof of that at all.
@@OffGridGarageAustralia to be asily cheked. Ten replicates of both grades is enough to run a t-test :)
The issue with the double screw terminal head is that you need a perfectly flat busbar (no protusion on the edges of the holes and edges) and we need to use double hole busbars with both screws. I have had lot of issues with these cells and the busbars included (had to sand them down time and again to get minimum voltage difference. Single screw terminals were a lot better although there 'seemed' to have less surface area. If you are using single screw busbars in these new terminals, there are issues.. not sure if its resistance or something else. My conclusion has been a perfectly flat busbar touching the whole surface..
We see this exact issue, we chose to make our own adapter for this same reason the bars got very hot, you had to have absolutely perfect pressure on each screw or it would cause the bus bar to warp.
You can get around some of that by adding some MG Chemicals 847 between the terminal and the bus bar.
I don't like these double threaded terminals. At the beginning I thought it is a great idea but as you said, everything needs to be lined up perfectly. The welded studs with their minimal contact area are perfect and never get warm.
@@OffGridGarageAustralia agree totally
@@OffGridGarageAustralia Not only that, customers we have will put thread locker and studs into the holes, then the thread locker will leak onto the base and cause conductivity problems. Big mess all around.
It is summer and hot in my city. My cells reaches 39⁰C after ~5 hours of 50A.
Maybe Automotive Grade Cells have better temperature performance.
Pure speculation. They come from the same factory and production line, they are the same batteries.
And basically from what you discribed in your video is that the automotive batters sit in a tighter mannor but other then that they are the same
I wonder if the difference is actually the number of cycles you can get out of them before they start degrading. I guess that test may take a few years though....
But even then, what are we talking about? 3000 cycles with B-grade and 6000 cycles with certified cells? I have done 75 cycles in one year with my battery shelf. Even at 2000 cycles, I'm 20yrs in. If they don't degrade because of aging before that.
I don't think you could live off the difference between years old b cells and new certified cells.
I have 16S EVE LF50K 3C rated and delivering around 56AH very very good but I don't believe they are matched because there is about 100-200mv difference at end of charge and having 50-100 mV difference in charges state. Even when I am using a JK BMS with 1A active balancer. Can't imagine what would happen with a passive balancer. Anybody know how I could improve the situation and get the delta down. Planning to polish terminals to decrease resistance. Also they can't deliver more than 1C with voltage sagging a lot even they are rated 3C continuous. Did I get bad cells even though they are delivering around 112% capacity?
Original LF50K has M4 terminals and I think they are meant to be welded with bus bars directly for upto 150A load (3C). Using bus bars and M4 screws on those terminals will create a lot of resistance that will be hard to avoid. If your 50Ah rated cell is giving 56Ah, that must be really good cells in my opinion. I have 4 LF50K cells, gives 52Ah but less voltage difference at 1C, I think it's because I have M6 welded terminals and thick copper bus bars. These M6 studs are welded by a third party seller, not original from Eve. May be you can try with thicker and wider bus bars too. But I would limit the cells to 1C without welded bus bars like in EVs.
You can try one of these capacitive active balancers and leave it on for a while when the battery is fully charged. This gives you a nice top balance to start with. If the cells keep drifting apart, check for the bus bar connections as you said. You can test the terminal connections when doing the 1C test just with a multimeter.
@@OffGridGarageAustralia I have the cells attached to a 150A JK BMS with 1A active balancer, the battery gets discharged to 48V everyday and then charges using a 12.8KWP solar array with 50A max charge. But the deviation is very high at 150mV full and 200mV full discharge with no one cell to blame. There is measure voltage drop between the terminals and the busbar - about 2-3mV at 50A and between the ends 9f the bus bar at round 1.12mV and the busbars are around 20mm2 tinned copper with SS bolts with split and normal washers. The pack has been manually top balaned to 5mV. Ans the balance trigger voltage is 3.35v with a deviation of 10mV.
So what about the difference in 4 years? didnt you already do some videos on the loss of the capacity on the grade b? Or did you find the same capacity loss results on the certified cells?
Who knows what is in 4 years? We are totally speculating here.
No, I made a video about the ~2 year old cells I got from different suppliers at a time.
@@OffGridGarageAustralia I keep reading that the b grade cells may test fine when new but are likely to depreciate in capacity quicker than the auto grade cells. It would be nice to see some evidence showing this may be false.
@@fathergratwick Or some evidence that it is true. It could be just another excuse to sell overpriced certified cells.
Some viewers here have these B-grade cells for many years and no performance issues.
@Off-Grid Garage I'm not disagreeing but it would be nice to see some testing to show data on this either way. I'm not in any way trying to tell you what to do here.
@@fathergratwick Once we see some evidence, we most likely have other battery chemistry and cannot buy these cells any more. If there are still certified cells on the marked in a few years time 🤷♂
Seit einigen Tagen sind wir strommäßig erneut autark hier in Niederbayern. Mir gefällt dein Elan "very good" 🖖😉 Bitte achte auf die "schlechten" Lifepos. hier in Deutschland sind kürzlich einige abgefackelt...
I've read the articles and watched it online. But it wasn't clear if the fires were actually caused by the batteries...
@@OffGridGarageAustralia Better save than sorry... 🖖😉
I have a dud cell , dam it will not charge over 3.4v when others head up tp 3.5v it stays at 3.4 ,why would this happen anyone ? 24v system 8 cell 280ah eve B grade, still under warranty
Excellent video and can't help out thinking this was in perfect timing for my complains regarding recent shipment I received from "one supplier".
This then leave out only one question, what is actually EVE standard of having cell doomed as pass or fail for automotive use. If capacity is the same and voltage discharge is the same, then what is it?! Although there are still load tests in RUclips showing that there is a voltage drop between cells with certain loads, and they are definitely not on mV category. So something is still not right. Maybe Andy has nothing but good cells on carage?!
Anyway thanks for video, it was again great.
Noniin, could be anything from not matching the IR curve as it should for matched cells (remember, capacity is only one thing, IR matching over the entire charge/discharge curve is another), SEI imperfections, to cosmetic imperfections. I don't think anyone besides EVE really knows what their quality check-list looks like.
Well the cells shown on other channel must be faulty, I have never seen any cell diving that low in voltage. And if they handpicked the fake Hithium cells for me to review, they did a pretty bad job as they are the worst I have.
Voltage under load and Self Discharge are the primary reasons cell pass or fail. Capacity is WH is the secondary criteria along with physical characteristics.
Great info Andy, hopefully this will put most of this capacity testing to bed. I cannot understand all the hype of "my cells are only 275 amps or I am getting 285 out of mine" as battery manufacture in not an exact science. (Yes it is getting better) How many of your 58 thousand subscribers have capacity tested AGM, lead acid or calcium batteries and can show results from them. Oh, sorry Andy, there's another test you could do. Have a great day Andy and may the sun be with you!!!!
Great summary, Glen. Love it!
Well. If I pay for 280Ah cell, it's not wrong to ask for 280Ah. Missing 10Ah from each cell will mean 160Ah total loss on common configuration which is close to 1kW capacity in total.
@@KossuJahvetti If you are running a 3.2v 16P 1S yes you are correct but if you are running a 48v 1P 16S then you are wrong it is still only 10Ah which is 480Wh or a 60w globe for 8 min. Do you also weigh every packet of chips?
@@glencooke494 LOL. It is exactly the same what ever your configuration is. A good book of Wh is a good start.
@@KossuJahvetti A lot closer than 1Kw I think🤔
You are BBQing again while dropping tree limbs. Get the beer out Andy and put another sauce on for me, mate. Cold and wet down here today.
But, how do the different cells recharge and balance? Are the A grade cells better at balancing after a full discharge??
If the internal resistance across all cells is identical they should keep in balance fairly well.
Very good question @OffGridGarageAustralia
No difference ein balancing I could see. I used the same equipment and both batteries charged and balanced just fine.
@Off-Grid Garage I have B grade cells, and if I dont charge them full every day, they go out balance by 150mv+ after a week. Now I know this could also be because of busbar resistance, but have you yet come to a conclusion with your passive balancing bms,s that it's not because of b grade cells.
@@Davido2369 Mine are drifting a bit as well and especially over the last winter period where I didn't fully charge them for months, they drifted. But it was not horrible and I didn't have to use an active balancer or so.
As you said, could be bus bars and connection resistance as well... You need to watch which cells are peaking and do some investigation. A simple multimeter across the cells can be enough to tell you if it is the cell or the connection.