Homebuilt ROVs Forum

Does anyone know how i can monitor the voltage of my onboard lipo batteries with my arduino?

This might do the trick.
http://www.robotshop.com/eu/lipo-fuel-g ... ensor.html

So i would need 3 of these for a 3s battery, but the arduino uno only has only 1 i2c interface so that probably won't work.

3S oh ok I will see what I can find.

I gather you are not connecting your batteries in parallel and using one pack per motor? How many packs total?

I'm thinking of using 4 5000mah batteries wired in parallel, and also i thought of wiring the balance plug of the batteries to the analog inputs of the arduino mega using a voltage divider.

Well if your packs are wired in parallel then you really only need one sensor on the mains. When lipos are in a parallel bank its just like one big pack anyway. 4 - 3s 5000 mAh packs become one 3-s 20000 mAh pack. As I understand it if all packs are equally charged with a ballance charger they will always (in a parallel configuration) discharge equally. No one pack will discharge faster than another.

So what do you suggest i use to monitor the pack voltages?

You could go this route. There are many options of sensors designed for Arduinos.

http://www.emartee.com/product/42082/Vo ... Compatible

Would something like this work?, and i can measure the current draw:

http://www.coolcomponents.co.uk/catalog ... p-433.html