[Itsgeoff]

My Samsung Galaxy S2's battery went dead because I didn't charge it when it was down!
The first times I tried turning it on it turned on and off almost instantly once it had got to the lock. Now it just vibrates (does this when you turn on) and does nothing. Help much appreciated

[B. Diddy]

Welcome to Android Central! How long did you try to charge the battery back up before powering the phone back on? Try charging it overnight without disturbing it, then power the phone back on.

[Itsgeoff]

I'll try that, thanks

[B. Diddy]

The other thing is that the battery itself might just be completely dead. If a lithium battery is allowed to discharge completely (i.e., to absolute 0%), it's irreversibly damaged. Phones typically turn off automatically when it gets to around 10% to avoid this, but if the battery lies around for days without being subsequently charged, it could potentially get down to 0%. Did this happen?