How to charge a li-ion battery from a cell phone?

Question

Batteries

In general, I have 11 li-ion batteries, the phones have been broken for a long time,
I would like to charge them. At the moment, I charged them directly from a 5v charger and they charged (But one battery was without a controller and went all the way to 5.2v). Is it possible to charge batteries this way, or are there more humane ways?

Answer 1

A humane way for the battery and your health is to use a charger in which you can set the charge current and cutoff voltage, for example Imax B6.

Answer 2

There are special chargers for Li-ion batteries, buy or order on ebay.

Answer 3

the fastest and cheapest option is to buy in any store of accessories for mobile phones, the so-called. "frog" for charging batteries separately from gadgets. (and google it for "charger frog")
if your hands itch to solder on your own, the space here is limited only by abilities and the availability of spare parts :). you can gut the mentioned faulty mobile phones in search of ready-made charge chips. they were widely used in devices 10 years old or more, then the charge functions, as a rule, were included in the power chips.
I bought myself this for "quick homemade": www.aliexpress.com/item/5pcs-lot-TP4056-1A-dedicat...