I recently bought 4 pcs of 280Ah LiFePO4 battery cells locally in Poland to DIY a 12.8V energy storage system, and I ran into several unexpected challenges.
First, balancing the cells properly took more effort than I expected. Even though the supplier claimed they were well-matched, I still had to manually top-balance them to ensure they stayed in sync during charging and discharging.
Second, my BMS setup required careful tuning. I initially had issues with overvoltage protection kicking in too early, and the low-voltage cutoff settings needed adjusting to prevent premature shutdowns. Your concern about the 3.0V cutoff is valid—it’s a narrow range, and LiFePO4 cells can become unbalanced if discharged too low. You might need a BMS with customizable settings to fine-tune the cutoff points.
Lastly, the actual performance of the cells didn’t fully match the rated specs. Some had slightly higher internal resistance than expected, which caused small imbalances over time. Regular monitoring is key to catching these issues early.
