12V Battery Monitoring

I am looking to work on a project that can monitor various batteries on a boat. I have four battery banks that need monitoring. My initial thought was a Raspberry Pi and four INA219s to monitor each bank. I have subsequently read INA169’s instead so am now a bit confused (it doesn’t take much). Can anyone recommend a better option, and perhaps even a “read this”?


Hi Paul,

Are you looking to monitor the current being output from the batteries or just the voltage of the batteries?

Just voltage

Hi Paul,

If you use some controller that has analog input this would be much simpler. The Pi has no analog to digital converter, so you would need to use an external one:

This can only read up to 5v though, so you will need to make a voltage divider.

Or you can buy one:

and feed that into your ADC, then into the Pi. Make sure everything shares a common ground or you can fry your electronics!