Does plugging my iPhone into a 2 amp charger ruin the battery that's made to charge with only 1 amp?

dsyanick wrote:

I have a car charger that puts out 2 amps when it charges. My iPhone only needs 1 amp to charge, and the charger that Apple supplies is 1 amp. When I plug my iPhone into the car charger, it charges fine, but I am wonder if i am ruining my phone or my phone's battery. Does the phone charge twice as fast with the higher amperage charger, or does my iPhone only take the amps that it needs?

A 5S will charge at the same rate with either the "cube" adapter or the 10 watt or 12 watt iPad adapter. Notice that I called them "adapters" - the charger is actually built into the phone, and will charge the battery at the correct rate regardless of the adapter you use.

I specifically mention the 5S (and earlier models). The iPhone 6 and 6 Plus CAN take advantage of a higher wattage adapter, and will charge 50% faster with a 2 amp (10 watt) charger.

While you didn't ask, it's OK to leave the phone connected to power after it reaches full charge, again because the charger in the phone is smart enough to prevent overcharging. So charging the phone overnight, every night is not only OK, it's also good practice.

nope, no harm at all, the phones and chargers are smart enough to just give the charge that is required, just make sure that you are not using un-approved chargers or cables, as they don't always have all the overcharge circuits needed.