question

Guessing these aren't lithium, but a lead based chemistry. Ideally they should be fully or equally charged before installation.

Small imbalances will even out at float voltage. But not ideal here. I guess you have no suitable charger for the individual cells. Suggest you connect a load like a light bulb across the high cell, lower it's voltage. Then restart the charge. But check voltage after the cell has rested for a while. You may need to do this with other cells. It's going to take a while, sorry.

Hey,

Yes, i don't have a charger for charging them seperatly. If I check the Cell Voltage, when it's idle (not charging\not discharging) for a while , there is almost no difference between the cells (<0,01V).

I also think there ist a small im balance between the cells.

Now, i plan to do the following:

-> charge the batteries in float mode for a longer timer period to even them out.

-> if one cell is to high, i will discharge them with a small resistor like you described.

i also found in a Victron Mppt manual some interesting information:

https://www.victronenergy.com/media/pg/Manual_SmartSolar_MPPT_150-60_up_to_250-70/en/configuration-and-settings.html

theres an "equalization mode", where the cell voltage is up to 2,65V/cell (31,8V)

So in conclusion, my cell with a voltage of 2,55V should be fine or am i wrong?

Regards

Dominik