# How many volts would damage a cellphone battery?

1. Jan 14, 2012

### shoes

I'm trying to charge my cellphone and would like to know how many volts would cause the cellphone battery damage? Also, how many amps would an average phone need to be charged?

2. Jan 14, 2012

### Studiot

How are you trying to charge it?

3. Jan 14, 2012

### Simon Bridge

Erk - don't try it if you value your battery.

The parameters depend strongly on the battery - cell-phone batteries are not built to a standard.
Generally you apply a very small current at a fixed voltage and the battery is charged when it's terminal voltage matches the supply voltage... so you seem to have the concepts backwards ... which contributes to the advise: don't try it. How you go about it is also important.

You can find someone with a similar phone and read what you need off their charger. Mine is rated 5V at 350mA. 5V is pretty standard but the current will vary between phones - I used to charge batteries with a variable PSU and a current divider - I'd start with a very low current through the battery and raise the parallel resistance until the battery got warm ... but then, I broke a lot of batteries figuring out the limits.

Work out the cost of a new battery against the cost of a new charger.

4. Jan 15, 2012

### davenn

Cell phone batteries these days are usually Lithium Ion. That type of battery has very specific charging requirements. doing it incorrectly can cause the battery to burst into flames or explode.
Do some google searching on Li-Io batteries

Dave

5. Jan 15, 2012

### Staff: Mentor

Last edited by a moderator: Sep 25, 2014
6. Jan 15, 2012

### davenn

nice one Borek

perfect demonstration of my warnings.
The Li-Io and Li-Po are both capable of that reaction if charged incorrectly

Dave

7. Jun 4, 2012

### sunjatan

It depends the maximum voltage that your battery can bear.It can over the maximum voltage on your battery said.