I need help with designing a 8 channel battery voltage / current datalogger

[sam_sam_sam]

I could buy a eight channel battery tester however all grounds are shared

What I am wanting to do is charger and monitor the voltage / current of at least 4 batteries at a time in series and use a computer for the data-logging

Does anyone on the forum have any ideas how I could do this

[stj]

Re: I need help with designing a 8 channel battery voltage / current datalogger

voltage is easy, get a microcontroller with enough analog chanels and just tap all the midpoints.
then use math to seperate the readings.
so the first cell is direct,
the second cell you deduct the voltage at the first cell.
the third cell you deduct the voltage at the second.
and so-on.

not sure how you read current without a common rail.

[sam_sam_sam]

Re: I need help with designing a 8 channel battery voltage / current datalogger

I want to do this with isolated voltage reading if possible

[stj]

Re: I need help with designing a 8 channel battery voltage / current datalogger

why?

[sam_sam_sam]

Re: I need help with designing a 8 channel battery voltage / current datalogger

why?

Because I want to test BMS balancing protection boards
Because I want to match battery for the BMS balancing protection board

Because just how accurate is use a voltage divider are you really measuring the actual voltage is or a rough estimate of voltage

[sam_sam_sam]

Re: I need help with designing a 8 channel battery voltage / current datalogger

I still have not found a solution to issue but still looking for one

Is there a way to monitor the voltage using an optic sensor as isolating barer I am just asking the question if could be done this and if it can how would you do this

[eccerr0r]

Re: I need help with designing a 8 channel battery voltage / current datalogger

I just thought of a possible solution but you won't like implementing it if you're not an EE as it has so many pitfalls... (Basically put a multimeter at every battery and read each one on its own) so I think you have to go with stj's method or electromechanical....