v1 iPhone, jailbroken and unlocked, working on T-Mobile. iPhone will not start up unless connected to charger (either ac, connected to computer or car charger.) Works fine then and when disconnected continues to work. If I leave brightness very low and just leave it on, it works ok as well. Once it goes to sleep it generally will not start up unless connected to charger. Battery only lasts a few hours. Is this problem due to the battery getting old and weak or is there another problem? Anyone? Thanks.