I was trying to make a 3 cell lipo pack charger using 3 of the TP4056, one for each cell. I encounter the same problem as (this gentleman). This is a comment from that forum question: "If you can charge batteries at different intervals then use relays to sequence one charge at a time." - @spicetraders Summary, commune ground, short.
The battery pack I'm using is a 3 cell pack, each cell being a 3.7v @ 2200mAh. Instead of buying a battery balance module, I'd like to try to make my own.
Because it is very inconvenient to use 3 different power sources or use a galvanic isolated power source which I read somewhere else, I'd rather use one power source.
3 TP4056 IC's (1 per cell) and a "supervisor" attiny85 IC + 3 MOSFET's.
The idea is to connect/charge 1 cell at a time for 1 second, then move on to the second cell for one second, and then, move to the third cell for another second. Repeat.
Now, in theory, would this work? if so, what would it be better, connect each cell to the charger for 1 second at a time, use milliseconds instead or minutes?