iPhone 4 won't charge on any other chargers just the one it came with.
I bought my phone from ebay and it came with a charger and a wall charger. My phone will not work with any other chargers just the one it came with. The charger works, but it won't forever, when it comes time to buy a new charger I'm scared it won't work with my phone. I have used my old chargers and my sisters chargers all with different wall chargers as well and they didn't work! What is the cause of this problem?
Please help!!
iPhone 4, iOS 7.1.1