help with a 3S 12V li-ion

Hi,

I have a design that requires a 12V power supply, I have been using efest 26650 cells (IMR) in series (3x 26650s at 5000mah to make a 5aH 12v supply) but they do not have over discharge protection, any ideas how I can add this to the design? I have arduino’s available (quite a few, uno’s and also some of the digispark attiny85 ones). eventually I want to have something similar to the sparkfun lipo fuel guage, connected to a arduino with an oled to provide % or hours/ minutes left, but not even sure how that would work with 3 different cells in series. any ideas/ input?

Unfortunately SparkFun doesn’t carry what you’re looking for, but something like [this might work for you.](https://www.amazon.com/KNACRO-Protection-Over-discharge-Overcurrent-Short-circuit/dp/B01J9BSJ80/ref=sr_1_4?keywords=lipo+protection+circuit&qid=1554937149&s=gateway&sr=8-4)