iphone 5 will not turn on and flash battery and apple logo

My iphone 5 is over a year plus old. A few days ago, it went off despite the battery being at almost a full percentage. I was only able to get it back on when i connected it to my charger and the percentage was still high. However, a day later, my iphone would flash a low battery logo and the apple logo for about ten seconds repeatedly when i connected it to my charger. It would not turn on at all, disconnected. I have tried the hard reboot method, but that does not work as my lock button is faulty! The method of pressing down my home button and connecting to a mac does not help either as 'some error' would occur, as stated by itunes. Does anyone have an other idea how to turn my phone on? I would not mind a method which requires me to restart my entire settings.thanks in advance!!!