Gas stored above a battery sounds like a recipe for disaster.
As for mentioned a few posts ago, index wipes are a very bad idea for plastic. For bug cleaning, I use the "magic eraser sponge". Its amazing!
I always carry a small first aid kit, a crescent wrench, a leatherman, a butane lighter, some snacks in case I'm roadside for longer than expected. Also, an extra cell phone battery, or battery booster is a good thing to consider.