Apple describes how its new cover could contain solar panels that keep your iPad's battery topped up while you're out in the sun, and external sketchpads that allow users to jot down notes on the outside of the case when they're in a hurry. (cultofmac.com)
That will see the 3000mAh battery topped up much faster than the older model, so if battery endurance is a concern, then charging no longer is. (pocket-lint.com)
If you can get a trickle charger with a «maintenance mode», you can leave it permanently attached to the car and it will keep the battery topped up and stop it going flat in the first place. (mechanics.stackexchange.com)