Over at Hackaday.io [AndyHull] popped open some cheap LiPo battery ... the charge cycle for up to four 18650 LiPo cells connected in parallel. The controller also boosts the voltage to 5 volts ...

A micro-USB plug is used as a 5V supply to charge the battery, and a small slide switch is used to turn the board's power on or off. Two 100KΩ resistors also form a voltage divider for the ...

I was annoyed that I couldn't find a simple LiPo over-discharge / over-charge protection circuit ... power-down mode (to avoid discharging the battery even more). Once this happens, and once the ...