This half-inch square ultra-low power energy harvesting LiPo cell charger by [Kris Winer] uses ... the heavy lifting and has nifty features like battery health monitoring and undervoltage ...
Over at Hackaday.io [AndyHull] popped open some cheap LiPo battery power packs to see if ... while providing automatic shutdown if the LiPo cell voltage drops below 3.2v. Below that voltage ...