I bought the Xantrex PowerPack 400 to take with me on a camping trip because it provides not only a standard 12v cigarette lighter plug but also an AC power inverter with two built in grounded AC outlets for running atandard devices like a small fan or charging adapters or whatever.
The device's power storage provides juice for a very reasonable length of time ... which for most lower power items like cell phone chargers, LED lamps, etc, amounts to many hours of useful power, even days if used intermittently for low power devices. Will also power higher current devices, though, which is nice although stamina of the PowerPack400 will depend on the device's power consumption rate.
A built in meter displays percentage of remaining battery charge
The PowerPack has a handle built into the plastic casing and is a reasonable weight to carry conveniently. There is a storage compartment in the back for the AC charger and tips for the air compressor. Auto jumper cable is provided also but in a separate pouch due to size.
I bought the SUNLINQ 25WATT 12V solar panel to use for charging the Xantrex PowerPack. Worked fine but a solar panel is going to take most of a sunny day to fully charge this battery. if you plan to charge any powerpack with a solar panel, just make sure the voltage and current capabilities of the solar panel will match the charging needs of the power pack. CALL the Alt Energy Store folks. They were very helpful with questions like that.
There is a built-in air compressor to fill tires or a football or whatever ... it's a nice feature if you have the need.