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

Because with two batteries you can have different configurations, even if the arrangement looks the same. If you wire two 1.5v, 300mAh batteries in series, you get a single 3v, 300mAh power source. If you wire them in parallel, you get a single 1.5v, 600mAh power source.