You can consult with the charger's company and ask for the warranty. If you're out of the warranty period, it'd be a good idea to change one. I've been using RavPower 14000mAh and it's great so far. Love the capacity it gives to me, I can check how much power it left with its signs. You can get it here: http://www.amazon.com/RAVPower-External-14000mAh-Incredible-Motorola/dp/B00EHEEFWY