I'm building a 6S Lithium Ion battery pack with a nominal voltage of 22.2v. The pack will be enclosed so taking the batteries out to charge them is not practical; therefore, I'll need to add the charging circuit to the pack. Ideally, I'd have 6 TP4056 modules charging each li-ion cell and wired like this:
However, that is not possible with these modules as IN- and B- shorted together by design. Wiring it like that would short the batteries.
To avoid this, I'd have to have isolated power supplies for each module. 6 individual wall wart 5v power supplies would do the trick, but that is clumsy.
Ideally, then, I want to power 6 TP4056 boards with one 5v source.
Is it possible to "split" that 5v power source into 6 isolated 5v sources? I read somewhere that capacitors can be made to isolate DC sources, but I don't see any sources on the web backing that up.
Is there any better way to retain a 6S configuration yet be able to safely charge each cell? Obviously there are BMS's, but I do not have any stores that cell them near here. There are, of course, these ebay things but they do not have any datasheets.
6 DC-DC converters are not an option for me. I have literally scoured the internet today and am tearing my hair out over this issue. Would diodes work anywhere?