How much is too much

[eclimax13]

I'm looking to buy a high output car charger. Some good as high as 2.1 amp output. Is this tool much for a phone?

 

[Szadzik]

1A should be enough. I would not use more than that as charging that fast will shorten the battery's lifespan.

 

[tekchic]

I have a dual 2-port USB car charger that charges the 2.1a (I use for my iPad) and the 1a for smartphones. I have charged my phone with a single 2.1a before and I believe it is a "step-down" method where it just uses the lower amperage.

I could be wrong though...but I haven't had any battery issues when I've charged on 2.1.