I have a 40ah LifePO4 battery, sadly it recently developed a BMS fault, so that despite charging, it would only measure 5.1v, with no current.
After taking it apart, lots of careful circular saw, I found that unplugging, and plugging in the BMS again fixed it. The cells themselves are decent, but I wish they'd use a more reliable BMS, or had an external reset button.
I suspect my LiitoKala battery contains used cells.
I purchased a total of four 12V 200Ah LiitoKala batteries in two separate orders via AliExpress from the LiitoKala Battery Store, apparently now operating under a different name, namely VariCore Overseas Warehouse Store. The batteries were very professionally packaged, and they looked good upon arrival — nothing to complain about in that regard.
Unfortunately, one of the batteries started losing capacity significantly after a short period of time. Since I use them in a 24V 200Ah setup (two in series), the faulty battery made the whole system unusable. I contacted the seller, but we were unable to reach a solution.
I also reached out to LiitoKala, the manufacturer, twice. Unfortunately, I never received any response.
Out of curiosity and necessity, I carefully disassembled the faulty battery and was shocked to discover what appear to be used cells inside. In my opinion, this explains the battery’s poor performance.
I plan to post a video about this on YouTube in due course, so that viewers can form their own opinions based on the facts.
disappointing
I bought 8 Lifepo4 60 Ah cells and checked them individually by charging and discharging.
I already have some lifepo4 cells from well-known manufacturers (CATL and EVE Energy).
The cells delivered are significantly worse.They are much cheaper but unfortunately
still a bad deal.
Why?
- significantly less capacity than indicated. I have
measured values between 39 Ah and 47 Ah,
depending on the discharge current.
- approx. 39 Ah at 20 A discharge current and
approximately 47 Ah at 5 A discharge current.
- The cells cannot cope with high discharge currents.
Discharge rates close to 1C (60A) lead
to a significant (below 3.0v) voltage drop after a
short time. I didn't even try 3C at all.
- The packaging is good, but the cells still have
scratches and small dents. That can't come from
the transport.
- The cells have different capacities and internal
resistances. At 20 A discharge current I had
values between 36 Ah and 41 Ah. The cells are
therefore too different to be able to build a
reasonable 24v battery from them.
shortly: Significantly less capacity than promised and not usable for most applications due to the poor high current properties. Sending back to China is not an option due to the high transport costs that private individuals pay for dangerous goods. Was an attempt and failed. My bad.