Battery charging

Thread Starter

mehoody

Joined Dec 15, 2020
3
Hello everyone !
Im new to this forum. Im here cause I have a question about charging lithium batteries.
It is about my phone after damaging the charging connector I couldn't find a replacement part for the charging module. So I decided to solder a generic 5v lithium battery charger directly on the battery terminals (non removable battery) after hours of charging the phone still shows 1% battery although the battery voltage is 4.2v.
Is there anything Im not getting here?
 

MisterBill2

Joined Jan 23, 2018
18,061
Unfortunately soldering to a battery will usually melt the seals and result in a very short battery life. In addition, the charger connection may not have been correct.
 

Audioguru again

Joined Oct 21, 2019
6,647
The charging connector on a phone is the 5V input to the charger circuit that is inside the phone.
You connected the 5V power supply to the 4.2V battery and you are lucky that the over-voltage battery did not explode, maybe the battery has a protection circuit in it.

When a lithium battery is properly charged by a constant current charger circuit, when the battery voltage reaches 4.2V then the battery is far from a full charge and the charger circuit is limiting the voltage to 4.2V.
 

LowQCab

Joined Nov 6, 2012
4,004
Put all of your important Files on a Memory Stick if you can, then buy a new Phone.
A Computer Shop, or a good Phone Repair Shop, can probably retrieve your Files for a stiff Fee.
This should really send home the message of why it's important to make regular Back-ups.
I learned my lesson well.
Plan on replacing your Phone at maximum, every 3 years, even if it's working like brand new.
LiPo Batteries have a finite number of Recharge Cycles, usually around ~1000 or less, in the average Phone.
Also, USB Connectors do wear-out, and become intermittent.
Keep your Phone away from Heat and direct Sunlight at all times.
Do not leave your Phone On-Charge continuously ........ when it's fully charged, disconnect it.
Don't buy an expensive Phone,
it will hurt much less when you have to replace it,
and they don't last any longer than a brand new 2 year old generic model,
which you can sometimes get for free with a new Account or Plan.
.
.
 

Thread Starter

mehoody

Joined Dec 15, 2020
3
Hhhh,
Of course not. I used a lithium battery charger circuit.
The battery charges to 4.2v but the phone keeps showing 1%
 

RPLaJeunesse

Joined Jul 29, 2018
252
The phone will measure the current flowing into the battery (computing the added charge in coulombs) as well as the voltage. You bypassed that measuring circuit. The result is that the phone doesn't know the battery is charged to 100% coulomb capacity, just that the terminal voltage is up. Since it thinks no coulombs of charge went in it continues with the 1% display.
 

Thread Starter

mehoody

Joined Dec 15, 2020
3
The phone will measure the current flowing into the battery (computing the added charge in coulombs) as well as the voltage. You bypassed that measuring circuit. The result is that the phone doesn't know the battery is charged to 100% coulomb capacity, just that the terminal voltage is up. Since it thinks no coulombs of charge went in it continues with the 1% display.
this is what I thought. In other words the phone is no longer usable?
 
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