DIYrich
Solar Wizard
Show a pic of the voltages when they are at 70%. Should be around 3.30vMy batteries were 70% when I start using them.
Anything below 3.0v per cell, and you will have fast voltage drop. There isn't much power left at that level 9% SOC on its way down to 0% at 2.50v.
From your earlier post, it looks like Cells 6 and 14 are having problems. Did you top balance? That is what is probably causing your undervoltage cutoff by the BMS to protect the battery.
Do you have a Shunt to measure the actual energy going into and out of your battery? It could be that Cells 6 and/or 14 have an internal problem that is sinking power from the other cells and causing your "self discharge". Do you have a temp sensor on those batteries? Are they running hot?
Last edited: