The title pretty much says it all; the context I present is this: I have a cordless mouse that takes two AA batteries to function. If, for some unfathomable reason, I took ONE battery out (to save on battery life), will the remaining battery still be drawn on, or no?
Not a life-changing question, I know, just curious.
If your batteries are connected in series, which is usually the case, and you remove one of them, the other will NOT be drained, because it will no longer be part of a complete circuit, thus no longer powering your mouse.
OTOH, if your batteries are connected in parallel, then removing one will drain the remaining battery very quickly and may damage the mouse, which is looking for not only a specific voltage, but sufficient current as well. And one battery may not be able to supply it.
I would bet strongly that the first case is the reality here.
The battery orientation may not necessarily tell you anything. My cordless Logitech is powered by batteries in parallel. It runs perfectly fine with just one battery, although I haven’t tried it with only one for more than a few minutes at a time.
Just wanted to add one thought on battery orientation -
If the orientation of side by side batteries is the same it may be a guess as to parallel or series, but I can’t think of any design reason to orientate batteries in opposite directions for a parallel circuit.