You can actually use higher amperage chargers, like the kind that come with tablets, to get your phone charged up in less time than it would if you charged via USB or using the charger the phone came with, and it won’t cause a problem. An iPhone charger delivers 5 Watts (5 volts at 1000 mA).
Is it better to have more cold cranking amps?
Well, that’s still very important, because cold, cranking amps tells you the ability of the battery to do work right now. And the higher the cold cranking amp rating of the battery, the better it is for your car. But, don’t get that confused with cranking amps – CA. The cranking amps are rated at 32 degrees Fahrenheit.