My rechargeable AAA’s are 1.2 V capacity and I was wondering at what voltage are they supposed to be recharged?
Something around 1.45V generally.
When they’re around 1.2v at rest they have pretty much expended their stored capacity. But I generally don’t bother monitoring NiMH voltages to determine such things because it’s pretty obvious when they need charging. If you’re ever in doubt, just throw ’em in. An occasional full cycle keeps them performing well, but generally speaking you can just relax about it.