Tag: dead phone

how to fix a dead Li-ion samsung battery

More then a year a go I put away my old Samsung phone in its box.

Totally forgotten about it I had an idea to play with it again so I tried to start it up but nothing happend.  We just need to put it in the charger again right? After a few hours charging the phone was still playing dead. Nothing nada njet niks!

Searching on the many webpages about Li-ion batteries I came to the conclusion that the best thing to do is to buy a new battery. uh huh. Now that is not going to happen.

We know that you need a bit of current in the battery for some phones to enable their in build charging circuit. But how to get it charged without a fancy charger?

If you don’t mind to let a battery explode in your face then there is a little trick.
Needless to say that you might void your warranty and you might loose some limbs doing this.. We gonna jump start it! If it works for a car why not try that for a Li-ion battery…

If you want the science behind it, why this actually works, than please search and feel free to comment 😉

This is what I did:

Strip one side of the USB cable,and tape the right poles to the battery.

USB cabble to Samsung battery

As most of the time, red goes to the + and black to the –

I used some high temperature tape that u can use for soldering. But any good tape will do.

Plugin the USB cable and keep your fingers crossed now you still got them.

After 20 minutes I pulled the plug, got rid of the the tape and inserted the battery in the phone.

Now its charging, and the phone works!

Did I tell you that this isn’t the right way to do it?
I warned you about the fact that it could blow up in your face?
I mentioned that it might void your Samsung warranty?

Yes I did! Happy hacking!

Phone is charging again

Chatting with Max from Frozen Electronics and he came up with this tip:

“Max: You could destroy the battery, the chargers have a current-limiting PNP transistor in them!

Max: In the future, there’s a pretty simple constant current circuit you can build if you’ve got a P-channel MOSFET around somewhere. the chips are a dime a dozen on Newark/digikey (even ebay) and you can control the voltage and charge speed with potentiometers. almost like a universal li-po charger.

Max: Here’s the chip, the datasheet has the circuit in it, it’s really easy to use. there’s versions of the chip for all the common li-ion voltages (4.1, 4.2, 8.2, 8.4). It’s all based around a p-channel mosfet pass transistor. http://www.ti.com/product/bq2057

Thank’s max. Might try that one next time!