Alkalines in a flashlight should be good for several years if it isn't used much. I would NOT recommend using rechargeable batteries as they self-discharge and you'll end up with a nearly dead flashlight in 6 months with no use.
Tell you what Max, you wanted to know what one of my super-cap projects would be? You linked to it! With one of
these it should be plenty bright.
In all seriousness, I keep in my car(now):
- Factory jack kit
- A pair of panty hose(everyone wonders but it's in case the belt fails, I at least get my water pump going again to the next town)
- Tow strap
- Two ratchet straps
- Your typical pliers with wire cutters and adjustable wrenches.
- 2x 3/8 metric socket set(Deep and normal socket) w/ ratchet, breaker bar, and extensions
- Set of metric wrenches
- Fluorescent work light with 20' cord to cigarette lighter(If my battery can't power this I'm not going anywhere anyways)
- Cigarette lighter to battery terminal clamp adapter(What if I blow a cabin fuse!)
- Fuses
- 5 collapsible, reflective roadside triangles for those idiot drivers that might not see the emergency lights flashing
- A self-made coolant hose repair kit that includes a 2" diameter copper coupling, 3/8" copper coupling, 4 hose clamps, and a razor blade
- Electrical repair kit including liquid electrical tape, crimp fittings, and two spools of 14 gauge wire.
That's about it. Believe it or not the utility bin in the back of the Durango is only maybe halfway full with all that stuff crammed in there.