Measuring individual cell voltages of a baterry pack

Hi,

I would be glad if you could help me to solve my problem.

I have 4 individual LiFePo cells connected in series, but i need to measure voltage of each cell individually, not to exceed 3,65 V each. I´m using arduino uno.

Thanks for reply

Usually batteries like yours have a balancing connector (not the main discharge connector). This balancing connector should have the following connections: GND, cell1 voltage, cell1 + cell2 voltage, cell1 + cell2 + cell3 voltage, and cell1 + cell2 + cell3 + cell4 voltage.

You'll need a circuit that measures the voltage difference between two of the connections to get the individual cell voltage. Thankfully, you don't need to do it for the first cell, just measure the difference between cell1 and GND and you'll be good. The other cells need the circuit I described earlier.

Such a circuit could be an opamp in difference configuration for each cell other than cell1 (see link).

You might even be able to use this

Your requirement is not easy to do with an arduino.
@There are specialised charging IC's which can help , they may be much cheaper than trying to brew your own.
Stacked battery packs for lipo and lipo4 exist which are probably cheaper to buy rather than make.

lednicky1:
I would be glad if you could help me to solve my problem.
I have 4 individual LiFePo cells connected in series, but i need to measure voltage of each cell individually, not to exceed 3,65 V each. I´m using arduino uno.

So why are you trying to measure the voltage of each individual cell ?