Is it possible to charge 2 3.7v batteries in series with a TP4056, if not, what circuit would I need? Is it at all possible to charge two 3.7v li-PO batteries in
7.4V Two Step Lithium Battery Charger Circuit - CC and CV Mode : 9 Steps - Instructables
How to make a low battery indicator for a 7.4V 2S Battery pack? (more info in the comments) : r/AskElectronics
How to make 7.4 - 8.4V DC 2 Battery BMS 2S 18650 circuit potection Diagram - YouTube