Possible to monitor the voltage of a 3S battery?

Components & Accessories Power
1

I’m working on a project where we have an E-Flite 3S 11.1V 2200mAH battery to trigger a valve via a relay controlled by a Thing Plus. The Thing has its own 3.7V LiPo battery. Since the 3S has the plug for the balance charger would this also be a good way for us to monitor the voltage of that battery?

I have read about how to use resistors to make a voltage divider. What would be ideal would be to use a Qwiic breakout board with the 4 pin 3S battery connector on it. I’ve been unable to find such a thing. Does anyone know of one?

Thanks.

2

You could use this https://www.sparkfun.com/products/13777 (currently out of stock) wired to the battery with this https://www.sparkfun.com/products/14576 - since ours is out of stock, I do know that RC/drone shops will sell rx/tx that accomplish the same thing

Best of luck!

3

How do the 4 wires of the battery get connected to the two inputs on that board? I think the battery contains multiple cells and a charger knows how to make sure they’re charged equally.

4

The 2 two outside wires on the balancing plug are what you want.