liitokala Official Store

benja.min47

New Member
Joined
Oct 25, 2020
Messages
50
Hello, I received my lifepo4 liitokala 105Ah yesterday and I am doing the 1st tests. For the occasion, I bought a YAOREA YR1035 +. On the other hand when I take the measurements there is a big difference when I take at the top of the thread or at the base of the stud (see photo). I get 0.82m at the top and 0.40m at the bottom! Is this normal? What measure should I take?

Otherwise the cells are not swollen and display 3.28v of voltage. On the other hand, I discovered that like most of the cells bought on Ali, the qr code was scratched and masked ...
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thegoogler

Solar Enthusiast
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Apr 15, 2021
Messages
97
Test at the base of the stud, not on the stud itself. Your lugs or busbars will rest on the base and should be tight against it. It's counter-intuitive but the stud is there to secure the lug/bar to the base, not (necessarily) to conduct electricity.
 

benja.min47

New Member
Joined
Oct 25, 2020
Messages
50
Test at the base of the stud, not on the stud itself. Your lugs or busbars will rest on the base and should be tight against it. It's counter-intuitive but the stud is there to secure the lug/bar to the base, not (necessarily) to conduct electricity.
Hello, you are absolutely right, this makes a lot of sense. So these batteries have a very good 0.40m ohm IR on average.
 

benja.min47

New Member
Joined
Oct 25, 2020
Messages
50
I will move on to ability tests soon but first I balance up.
There is another thing that worries me, a poorly done weld. there is a risk of leakage?
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thegoogler

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Apr 15, 2021
Messages
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Generally no, the base is flat and thick and the stud is welded on top. I suspect if you insert something non-metallic in there (toothpick, zip tie, etc) it will stop as it hits the base that the stud was welded to.
 

thegoogler

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Apr 15, 2021
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tl;dr - My Liitokala cells (from the official AliExpress store) came with only 90% of advertised capacity. Possibly less if I were to put a real load on them. I highly suspect these were used cells.

I pulled my Liitokala battery from my trailer for the winter (probably unnecessary but we do get -20F nights in Chicago on occasion and I couldn't see any reason to store it like that if I could put it in my basement). Since I have it in the house, I figured this was a good time to do a full capacity test.

I started off by doing a full charge and bringing it up to 14.56V with my Kungber DC bench power supply set to 14.6V and 8.5A, as I've been floating the battery at ~90% SoC for the last two months and apparently the XiaoXiang/JBD BMS I have (Overkill clone) seems to reset the Ah used whenever there is no load and the voltage increases by 0.1V when resting (more on that in a different thread). That took maybe 5-6 hours. Starting cell voltages were 3.641, 3.635, 3.643, and 3.644 respectively... all within 0.009V so pretty well top-balanced. Cell 2 in particular has always seemed to run a slightly lower voltage than the rest during any top balance.

I then started a discharge test with the cheapo 35W load tester I bought off Amazon. (FWIW I'm unimpressed by that device, but after disabling the overheat protection I've been able to run at 2A load continuously). So yeah my test is running at 2A load, which is a but <0.01C. In theory this should provide for more capacity than a standard 0.2C load test. In practice however it hasn't. Ok so here's what you're still reading this post for...
  • Liitokala label says "280Ah"
  • CATL QR code says "867Wh" which is equivalent to 271Ah
  • Actual capacity as tested at 0.01C is either:
    • 262Ah if you believe the XiaoXiang/JBD/Overkill BMS
    • 275Ah if you believe the cheapo 35W load tester (I don't)
Realistically these have 262Ah capacity but have 271Ah CATL QR codes and were sold as 280Ah they are highly likely used cells. With 0.2C rated loads they probably have less than 262Ah... I'm guessing in the 240-250 range but who knows, yet? Anyway as you can see from the graph below, I ran out of capacity in the "280Ah" battery around the point when there should've been ~17Ah remaining. In fairness I stopped short of 10V because my cells are pretty unbalanced at the bottom (there's a delta of almost 0.2V)... closer to 10.5V as a bottom pack voltage for me.

1636673831362.png

Notes possibly of interest (in not particular order):
  • The load tester says it's generating a sustained 2.01A load but the BMS shows a 1.94A load which flutters to 1.87A quite a bit. Almost 2 seconds on each value, back and forth. Right there we have a 0.07A discrepancy with another 0.07A variance.
    • The way this registers I have to wonder if the BMS only has a 0.07A resolution, thus it's possible the 2.01A load is really ~1.90A and the BMS is calculating the load over a period of time so it shows 1.94A half of the time with the regular "correction" to 1.87A in order to balance the columb counter?
    • No idea if the cheapo load tester is accurate. At some point next season I may plug the load tester USB port into my trailer and see how far off (inaccurate) it is from my Simarine Pico system in which the shunts seem to closely mirror the BMS (within 1% or better)
  • I didn't fully load test this when I purchased the cells because I needed to put it into use for a long trip I had planned. Thus these cells have 4-5 months of use on them... granted it wasn't heavy use (the most I drew the pack down was to about 68%, most days I used <10% capacity, and for ~80% of the time in use I've tried to float the pack at 13.6V-13.8V when charging) but it's not perfectly "new".
  • My pack is compressed with 1/2" plywood, threaded rods, and lock nuts. I'm not using springs or anything fancy like that. I compressed when the pack was nearly full (and estimated the amount of force applied) and with a 0.01C discharge rate now that the pack is empty it does not seem like there's much difference if any in the tightness of the pack. So possibly I should reduce the compression a bit and/or try some of that special foam sheets between the cells
The above is just one test and it's the first full cycle I've done. I may try another test at a higher load next. Assuming the cheapo load tester doesn't overheat and die I'll report back if those results look significantly different (unlikely at 5A vs 2A but who knows?) If I can come up with another method of generating a higher load reliably I may try that as well to see if I can muster a 0.1C or 0.2C load test, though in fairness it's rare that I'm applying a load of more than 5A except for short intervals like when pushing out the slide in the RV or when the water pump runs so this would be more of an academic exercise than of value to me.

Side note: because the cells sold to me were clearly mis-labeled as 280Ah when the QR codes reflected that they were less, I had already negotiated a partial refund of these cells. The refund was based on usable cell capacity and included a percentage of expedited shipping costs. Ultimately I'm annoyed at the merchant behavior but financially I'm not crying over this as the benefit I've received from being able to use ~260Ah cells for the season (as opposed to waiting months for cells to come via slow boat) outweighs the small capacity difference and the hassle associated. After all I moved from a 100Ah SLA which I was constantly watching if I was camping in the shade (yelling at my kids to turn off lights and fans) to ~3x usable capacity where I just don't pay attention to the usage anymore
 

Short_Shot

Photon Sorcerer
Joined
Jul 13, 2021
Messages
1,820
I've found my overkill bms does not match my cba load tester.

I'm going to do another test soon with the two. If I remember I'll try to come back here. If you remember and want to know send me a message in like a week.

That said, I'm using 105ah liitokala cells that have a max capacity of ~80 to 85ah.

Since they were only $148 I'm not mad about it but I'll definitely never buy anything from them again.

My 280ah cells (again from liitokala) are only good for ~240 as well.
 

Jordi

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Joined
Oct 13, 2020
Messages
135
Has anyone ordered from "liitokala Official Store" in the US? If so, what was the shipping time?

I ordered qty4 100AH cells 6 weeks ago and was curious how much longer I might have to wait.

Thank you
Close to 45 days and still waiting (no tracking information). My SKU changed from 60Ah battery to 50Ah battery and many buyers report the 60Ah batteries only get you around 52Ah. Have to see mines yet...
 

thegoogler

Solar Enthusiast
Joined
Apr 15, 2021
Messages
97
Close to 45 days and still waiting (no tracking information). My SKU changed from 60Ah battery to 50Ah battery and many buyers report the 60Ah batteries only get you around 52Ah. Have to see mines yet...
I paid for express shipping on mine back in ~May, but even still they took close to the full time listed.

Given mine had what looks like an official CATL QR code, and had an official Liitokala sticker for even high Ah, but tested lower than both, I highly suspect the stuff Liitokala is selling is used. (Highlighting that for future people skimming this thread). I can't come up with any other reason mine would have official CATL QR codes yet test lower than stated with a measly 2A load. At < .01C rate these should've tested higher than 271Ah rated since the Ah rating is calculated at 1C discharge rate (at least according to the CATL specs for their 302Ah cells):

1636725055150.png

I don't have a way to put a 1C load on these, nor would I want to since my BMS is only rated for 120A. But I'm positive even at a 0.2C or 0.3C load these would test well below the ~262Ah I was able to carefully extract.

Anyway much like a lot of stuff on Ali*, for light use RV or solar installations etc like mine these types of cells are probably acceptable. Over a span of almost 40 days the highest load I put on my batteries was ~16.5A and the highest charge rate from my panels was 19.5A. That 16A load was very short-lived (furnace blower and water pump running at the same time with other lights/accessories on) - most of the time my load is well under 10A. If I was trying to run a microwave or hair dryer or something off an inverter with a much higher C rate I'd most definitely want to down-rate my installation.
 
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