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Hi, I am planning to charge a 7S?P battery of 18650 cells with a charge controller normally intended for led acid battery.
I created a spreadsheet with my parameters, I would like a second opinion. I have a hard time deciding on the float/absorption voltages. I live in Morocco, plenty of sun and dead laptop batteries.
In the spreadsheet we can see the defaults for 12 and 24 volts and the values I decided for the battery (column in grey):
EDIT: adding new values:
Thanks!
I'd set float voltage close to or the same as absorption (4,1V?)
new charge cycle: not important if absorption is high enough
I also think 4,15V is a bit high (4,1 would be my choice)
What (kind of) BMS are you using? does it communicate with the charger?
Thanks @Boekel,
I am relying on the solar charge controller for the over-charge and over-discharge protection. As for the cell balancing, I am using an active balancer which kicks in whenever the voltage difference exceeds 100mv and stops when it is 30mv or less. It does it on any stage of charge.
So I don't have a BMS.
The pack is not done yet, so I will do my tests with 7S1P for now, then add up cells as the system is stable.
I will re-upload another screenshot after adjustments tomorrow!
EDIT: added new parameters in original question...
Please don't use without a BMS that cuts of the pack / charger / load, it's not if, but when you will have a fire, the charge controller is -not- capable of preventing overcharge / discharge events.
