Why is my S3 battery draining rapidly?

[Dalton Barham]

Help my s3 battery is draining rapidly!

Im running cyanogen mod, on my galaxy s3, i love it - however, it seems to drain battery really fast, so fast that it drains when charging and turned on. it takes a day + to fully charge when off. Ive tried a different battery and multiple chargers, in fact it drained 20% of my friends battery (same phone ) just while booting up i've also tried a factory reset, and battery calibration.
Thanks

 

[Rukbat]

Re: Help my s3 battery is draining rapidly!

it takes a day + to fully charge when off.

That elimminates Cyanogen as a suspect.

in fact it drained 20% of my friends battery (same phone ) just while booting up

That would tend to eliminate the battery as a suspect.

i've also tried ... battery calibration.

Nothing to do with drain - that just keeps track of which apps are using what percentage of the total use.

It could be a bad motherboard, a short somewhere other than the motherboard (charging port board, perhaps), a pinched cable. It has to go on the bench for diagnosis.