Those small solar cells will maintain a battery but they can't recharge a dead battery.

We have one of these which can be left plugged into a car's power socket/cigarette lighter to be recharged or just maintained. I worked great for running a fan, a lightbulb, charging my cell phone, and assorted other low-draw items when Hurricane Ike hit last fall.

From the manufacturer's website:
Product Features
* Runs 115-volt AC or 12-volt DC products anywhere
* Built-in 400 watt inverter
* Sealed, non-spillable 20 amp-hour AGM battery
* 250 PSI Air compressor for inflating tires and small sports equipment
* Jumper cables designed for safe and efficient jump-starting
* Built-in light provides illumination in emergency situations at home and on the road
* 3-digit display allows for easy battery status monitoring
* Audible alarm signals overheat and under voltage conditions
* Overload and over-temperature protection to ensure longer inverter life
* AC charger stored in the unit
* Recharge at home or from a vehicle

-Blast