Maximum current is 700 mA according to the specified characteristics (the same as the wall charger.)
Test in support, he managed to recharge the phone while using GPS (it's obviously much slower than if the phone is in standby), unlike some compatible models. Insufficiently powerful, they may not even manage to provide enough energy for the phone will not discharge, which is somewhat unwelcome if one must drive a few hours ...
The operating LED lights up only when the unit plugged in, is actually powered: well thought out, this is not the case in all chargers.
