I'm building a project which needs to fit in a wallet. I have an Arduino Micro hooked up to a nRF8001. I attempted three button cells wired in series, which provided a solid 7.5 volts, but only
A 9V battery successfully powers it, but that's too big to fit in a wallet. I was considering using an
A27 battery, but even that's thicker than I would like.
Is there any battery I can use that's a reasonable thickness, and won't explode on me? Thanks!...