How to charge your cellphone or smartphone with AA batteries. You will need an universal car charger with built-in USB connector, car battery adapter with clips, usb wire to connect to smartphone. Note this charger is a slow charger. It takes one hour to charge 10%. Great for camping and hiking where there is no access to electrical power, but still have access to cellular network and/or GPS signals.
Tip: To speed up the charging power, turn off the smartphone or put it in sleep mode while charging.