Hi, I have used iphone 3GS model-A1303. I haven't used it for a long time and when i recently tried to turn it on it first displayed a battery flat icon and later it showed me the apple logo and then turned off. I charged it for 4hrs and still the same. So I enabled DFU mode and itunes recognized the device and when i tried to restore it posted that the device was previously in DFU mode now it has been restarted but my device is still in DFU mode. I suspect that this is a battery issue but before buying a new battery i need to make sure that the device is in working state. is there any way to find that or boot into device without battery. Thanks!