The new lithium-ion mini jump-starters on the market are a convenient way to have a jump pack and power supply stored in your vehicle.
Most of these fit nicely in a glove compartment or center console. In addition to having clamps for jumping a car battery,these battery packs have USB ports and some have adapters for a laptop .
One item missing is a female cigarette plug . While most electronics use some sort of USB interface for power there are still some that use a cigarette plug.
A simple Internet search revealed a 5VDC USB to 12VDC cigarette plug.
A quick test with my Fluke and sure enough there is 12 VDC. This will be perfect for using my XM portable radio out at the camp site .
Badlands Expeditions 