My solution on this issue was to buy a Morphie case/battery unit for my IPhone 4S. This not only almost doubles my battery storage capacity, it allows me to charge the combined uni with a miniUSB cable. That fits onto the Apple supplied wall charger AND lets me continue to use my old Energizer 2AA lithium Charg-To-Go, as an emergency backup. For the car I have two DC coil cord chargers. One to go directly into the IPhone, without the Morphie. The other with the miniUSB connection, a leftover from my Blackberry, can charge the Morphie alone or both units if they're connected.