I have an LG Quantum C900 Windows 7.5 phone. I accidentally didn't have the charging cord plugged in when I thought it was, so instead of charging it fully drained. Now when I try and charge it all I get is a picture of a battery that has a red stripe at the bottom. I read elsewhere that you can get over this by removing the battery for a while. I did that and still have the battery icon on the screen. I've had other phones that I didn't use for months and they recharged. Is this an issue though - let the battery go dead and it can go bad?
The LG Quantum C900 uses a lithium ion battery. If you run it completely dead it can be irreversibly ruined. However, the electronic circuitry is designed to make it more difficult to drain. It is designed to "shut off" the phone when the battery is around 2-3% charge remaining. The battery will still naturally discharge and it is possible for it to completely drain.
My suggestion would be to plug it in and wait up to several days. My boss had an LG Windows Phone he let sit for several months and it took about two days of charging for the phone to wake up again.