> That has to cut down on the thickness as well since the Badger 2040 is designed to take AAA.

Would it be ok with the lower voltage of NIMH rechargeables? I really dislike primary batteries.

Edit: found the answer.

> 2x AAA rechargeable (NiMH) batteries only puts out 2.4V which is, strictly speaking, not enough for Badger. However, in our tests it keeps on truckin' down to an input voltage of 2.05V (without the LED), so if you want to use rechargeable batteries that should be fine.

AAAA is popular and as cost-effective as CR2032 (aka: bad value, but less-bad value than most other batteries of this size). Note that CR2032 is toxic, so AAAA is somewhat preferred.

AAA and AA have much more energy-per-dollar. I mean, so does lead-acid but I guess that's too big lol.

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Specialty batteries, like CR123A, seem to fit the bill for this size much better. But those are so, so much more expensive. I feel like the only two cells worth really considering are AAAA and CR2032, despite their deficiencies.

Exactly! The device is approximately 12mm thick. I will upload a side shot shortly. I appreciate you bringing this up, it's an excellent point! To be honest, it is still a bit thicker than I had initially hoped for; however, when I weighed my options - solder 26 devices by hand vs use pre-made components -- the decision was much more clear.