12v LiFePO4 system, installed and operational now for several months. It was balancing as expected according to our settings. Suddenly it seems to not be balancing, even with a high delta, current flowing, etc. We have obviously done something but I'm not sure what.
I know the basic requirements for balancing are:
- At least 300mA charge current
- Cell voltages (all??, or only one?) above the Cell Balance min
- Cell voltage deviation above the Cell Balance min dV
We had all those boxes checked, yet no balancing was going on.
Here are a couple of guesses:
1. We've been talking about changing our balancing settings (changing the delta, and the beginning balancing voltage). We MAY have gone in and changed the settings and saved parameter settings, but NOT actually powered off/powered on the SBMS0.
Q: Would that cause it to stop balancing altogether, or still balance at the old settings? (We
can't remember if we actually did change the settings or just talked about it, but I know we have not powered of/on the SBMS0)
2. Heat related? All the screen shots I have of balancing near charge termination, the SBMS0 temperature was around 73-75 F. (22-24C). It summertime now and we are off the dock with no air conditioning. The SBMS0 FET Temperature today was 81F (27C). Could there be a protection setting that shuts down balancing when the temp gets too high?
I searched for an old thread about balancing but didn't find one--lots of discussions about balancing buried in other discussions, so I thought I'd start a thread that just addresses this one question.