Good news,good news.

We have the portable solar chargers available in 12,16 and 21Watt versions now.
These are for parked cars.
So may you have a car you don't drive so often you might want to consider to have one of these, unless you want to call for a jump-start and reduce the life-time of your battery significantly.
Not to mention fleets like rental companies, dealerships...etc.

More about garage equipment and solar chargers,click here

Portable solar battery charger

After a long journey the portable solar panels has arrived.
Just mount it on your car window, or top and charge your battery with the power of the sun.

No installation needed, just plug and play
This unit recharges the power you use for the car electronic,so the engine can run on less fuel.
Don't forget.Even if it seems you can easily generate power with your engine on, it still burns more fuel.
As the matter of fact every electric consumer in the car makes your engine running harder therefore needs elevated fuel consumption.
Using Solab the engine doesn't have to recharge all of it, as it has been charged without the engine running.
check:
Portable solar battery charger