Is there a device to hookup to cellphone charger

[mrel]

Hello
At&t sale person say cellphone don't have circuit built in the phone to stop charger from over charging the battery is that true?
If that is true , is there device to hookup to phone to stop the phone from being over charging the phone battery?
mrel

 

[Audioguru]

The sales person is wrong. All Lithium-Ion battery chargers detect a full charge then turn off the charging to avoid an explosion and/or fire, and let the battery last a long time.

 

[mrel]

Audioguru thank for your reply, have question.
What you said is true than (All Lithium-Ion battery chargers detect a full charge then turn off the charging) .
Have two cellphone one is ( Ulefone) ( Umidigi ) when charge cellphone leave charge cord connected to phone until ready to use than disconnect charger cord, people tell me reason for my battery in phone start swell because i leave cord connected to phone when battery full charge.
So as you said charger should automatic disconnect so what causing the two phone battery to swell in less that a year of use?
mrel

 

[Bluejets]

so what causing the two phone battery to swell in less that a year of use

Cheap Chinese batteries is one reason.

 

[mrel]

Bluejets
That is a problem almost all battery for cellphone made in china .
mrel

 

[Bluejets]

I did say "cheap Chinese batteries".....

 

[VenomBallistics]

In RC airplanes and drones, battery swelling is a fairly common issue.
It is the result of draining the battery at a rate that causes it to overheat.
Often times, they seem to slap any C rating number they like on the pack. It doesn't make it true