Cigarette lighters in old airplanes like mine were meant to light an occasional cigarette - not power iFly's, iPads, Androids, cell phones, etc. I wanted a seperate power supply available for the portable devices that I carry, just in case the primary power/nav systems go south. Additionally, I wanted the ability to jump in a friend's plane and power up my own GPS and ADS-B systems and maybe even charge a phone or two, even if there wasn't ship's power available. So I cobbled together the attached portable charging station, the size of a small ammo box (actually, it IS a small ammo box). Since the box can also be plugged into the ship to keep it "topped off" in flight, there is a Schottky diode on the charging side to prevent the box from energizing the panel when the master switch is off. Currently it contains a 12v 14Ah sealed battery, but a smaller, lighter 10Ah battery was enough to fly 9 hours while powering the ADS-B box without dropping below 12 volts. With the bigger battery, the whole thing probably weighs about 10 pounds and should power an iFly 720 and an ADS-B for several flights between charges. It's also been handy for motorcycle camping and a 12v source around the pool. With more pilots adding portable devices to the mix, I thought I'd share my portable power idea. The ink pen in the pictures is for a size reference.
The black switch in the middle/center controls power to the bottom two "main" outlets, as well as the 3-digit LED near the top that displays the battery voltage (12.8, 12.7, 12.6, etc). The 3rd outlet, beside the power switch, is always hot and contains a 2-port USB charger for phones, etc. The red switch controls the vertical LED light strips that are on the edges. These lights are a great help when loading/unloading the plane at night. The charging port is near the top, to the side of the voltage display.