I'm trying to make a powerful hand light that's smaller and better than any other (like Linux). It conisists of a base off of 12V automotive light which uses the home decorative "display case" bulbs (including reflector). the entire device will be, like 3 American inches in diameter. I need to find some small batteries that I can put inside it and still handle like 5 to 6 amps. Battery life isn't a major concern yet. With it, if I can continue my idea, you can change the brighness (and battery life) as well as the beam paturn by changing out the bulb. They're working on a fuel cell to push everything from laptops to cell phones with (which uses beer). That would be perfect for what I want, but that's still a ways off. Only one problem with this besides size, and I'll look at it later: heat from the bulb. I'll just slap it together for now and then look at how it behaves, then I'll go from there. Anyway, I need some very small batteries. I think (not sure) that some half AAA batteries will probably be a good start as to the size I need. Rechargeables are actually what I'm looking for, but nonrechargeables would be a decent starting point.

Now why would ANYONE waste perfectly good beer? Unless they use something like Budweiser to run it. That would be a fitting use for Bud.

...in my opinion, that's ALL a beer is good for, besides cooking. ...though that's beside the point. I just wanna know what the best battery for my purpose is.

If you are looking for some half AAA size then I think you need the N size. I've bought them at Home Depot... If you weren't set on 12 volts you could probably go to 2 9V batteries and be at 18V and still be compact...

I don't think 2 9V batteries would fit though. That is an idea I usually think about, but I think my bulb will blow if I used that. That is something I will try though. These bulbs are easy to get aholt of. That's one reason for this design I'm using. Plenty of brightness, but it's so dang hard to get those H3 bulbs like most spotlights and fog lights use.