How can I do my own DIY 1s LiPo charged?

[XxMandragoraxX]

Guys, I bought a 1s battery charger for my tinywhoop drone



the question is that I would like to know if I could make one myself. I have seen on ALI that they sell very simple circuits to act as a BMS. Is it possible that with a 4S at 2 A charger you can charge 4 batteries simultaneously, occupying each battery as if each independent battery were a cell in a 4s pack?



this is the circuit I talked about

[inse]

In principle you could wire up four single batteries in series and charge it with this thing.
But I would never do that as the batteries may have different capacity or charge state and this crappy circuit doesn‘t monitor individual cells.
I doubt it’s more than a current limited voltage source.

[thm_w]

Just get multiple 1S USB charger modules if you want to charge multiple batteries at once.

Using a 2, 3, 4S charger like you show doesn't make sense to do.

[XxMandragoraxX]

But doing this, te current get down so hard because each baterry is 550mAh. I mean if I use this litio charger for charge 1s LiPo batteries, How I should wire this?

Because I think that if you have a BSM with 4A and I connect the batteries in parallel, the current has to go down, right?
since the current would be distributed among all the batteries that were connected

[kjr18]

Easiest and cheapest way is to use 4 TP4056 modules, and wire every battery separately. Connecting them in series is possible, but then you need to power each module with separated power supply, their grounds isolated. Not an easy as sounds. You can get small dc/dc modules like  B0505S, but that's not really efficient and useful.

As for connecting them in parallel, they also should be at similar discharge level, because if one of them is a bit off, other cells might get overcharged a bit, and that one not, and this difference will get bigger with every discharge-charge cycle, until something breaks.

If you really want to charge them all at the same time, connected in series then you need a charger that monitors voltage of every cell and correct it if needed, something like hobby chargers.

[XxMandragoraxX]

Thanks so much. Ill get one of that, a little bit more expensive but more safe.

[kjr18]

You don't really need to buy a new one. That one you showed in first picture should work just fine.