New Basen 230ah question (but it applies to every smart battery i guess)

[dragonzzr]

Already one year with my first dump lifepo battery (Ampere Time 50Ah) and i was very happy that it was charging and discharging without problems with a victron 100/20 solar charger at 14.4 volts bulk when camping.
Until i entered the "magic" world of "smart" batteries and my happiness dissapeared and many questions appeared.
ok , here it goes the first one. A couple of days ago i got a Basen 230Ah smart with JBD bms (this is installed as factory bms). Settings have an overvoltage CELL protection of 3.65 which is totally legit. and PACK overvoltage is 14.6. Perfect !
BUT if one cell is out of balance and reaching the threshold, then BMS cuts in and disables charging, which is again perfect.
The result is as you can guess, is that battery charging never gets to a final voltage of 14.6 or even 14.4 but stays at f.e at 13.9. This otherwise perfectly fine behaviour continues on every charge and its not as my dump battery. How can i make it "behave" more properly? (reach 14.4V at full charge) without always cutting at lower voltage because of cell ovp?

 

[42OhmsPA]

Imo and that of many others there is more harm than good in charging to 3.6+v.
If you want to balance the cells, ensure balancing is enabled in the JBD settings (I would have it turn at 3.4v) and hold charging volts @13.8-14v.
Take a look at a charge / discharge curve for a lifepo4 cell and you'll understand why you don't need to take them up so high.

 

[dragonzzr]

Thanks, as your answer is in par with other suggestions i have found in similar problems while searching other threads.

 

[dragonzzr]

update: tried today to use a bench power supply to keep the charge voltage to 14V and noticed this behaviour while keeping an eye on the xiaoxiang app for the cells voltage. the highest cell #1 was getting higher and higher, the cell #2 - #3 were almost perfectly balanced and cell #4 was the lowest and getting lower and lower as the balancing fuction was running. the deviation started at 0.009v and by the time i had to stop charging after one hour, it has climbed up to 0.140v. is this normal or not ?

 

[dragonzzr]

quick update 2...just tested to discharge about 10ah and now strangely all cells are balanced within 4mv deviation !!!

 

[fratermus]

ried today to use a bench power supply to keep the charge voltage to 14V and noticed this behaviour while keeping an eye on the xiaoxiang app for the cells voltage. the highest cell #1 was getting higher and higher,

..

ust tested to discharge about 10ah and now strangely all cells are balanced within 4mv deviation !!!

One possible takeaway: stop charging LiFePO4 when it's full enough. Continuing to jam in Ah will drive imbalance.