Some kind of protection on the micro-board with the TP4056 module - who and from whom does it protect?

Question

Electronics

I want to buy a charger for a disposable electronic cigarette (a board and two soldered wires with crocodiles at the end).
On AliExpress there are already homemade products like this
one. I also found on Avito just such a

difference in the absence of a compatriot on the board. two chips and such boards are marked without protection
. For example , there is without protection and with it.

Question 2:
- who is protected from what? It is clear that the battery, but both types are created for charging.
- Can you charge batteries in single use through boards without protection?

Thanks

Answer 1

it is the simplest protection against overcharging and overdischarging.
if you are sure that the driver you are buying clearly keeps the voltage in CV mode (4.2 volts for lithium-ion), then you don’t need it.