ELI5. Why do most devices requiring AA or AAA batteries need at least two. Why not create a standard battery that is the equivalent of two or have common circuitry that only relies on one battery of a similar low profile?

Question

ELI5. Why do most devices requiring AA or AAA batteries need at least two. Why not create a standard battery that is the equivalent of two or have common circuitry that only relies on one battery of a similar low profile?

In: Engineering

Answer 1

Form factor most likely, decades of products made to fit individual cylinders producing 1.5 volts would mean your new shape would possibly not fit them, plus many devices now using lithium ion batteries.

There is also the wiring not being the same, if they are in parallel then it is only using 1.5 volts but if they are in series then it’s a multiple of that.

Technically, though only really worth it in an emergency, since AA and AAA (and C & D) produce the same output, you only need AAA batteries and can pad the caps with foil so they work in the device. The lifespan of those batteries will be less but sometimes it’s all you need.