Default [Q] Car Charger

I recently bought an Anker battery for my HTC Sensation and I've seen significant improvement in just a short period of time. I want to be able to maintain the battery properly and correctly so it will last a long time. So my question is, what is the proper specification needed for a car charger?

I've read that the car charger must match the battery specs so it doesn't damage it. I bought a generic brand a long time ago while using my stock battery and the car charger never really charged my phone while I was using GPS on it. So I then bought another car charger, but instead it overcharged my phone really fast. I'm not very technically apt in this field regarding voltages, amps, and ultimately battery itself so please tell me the proper car charger to purchase.
HTC Sensation 4G|z710e
Radio: 11.76A.3504.00U_11.24A.3504.31_M



ROM:ViperS 3.1.4 - Android 4.1.1 - Jellybean