On an aside, I got all excited about NiMH a few years back and ran stuff in earnest off them.
The problem I found was the 1.2V vs 1.5V nominal voltage. Too much stuff I own is fussy and as soon as the cells lost a bit of charge, or worst, later, became tired, I just couldn't run stuff for any length of time.
My 4cell maglight: did try relamping it, but it was difficult to find a bulb at the right voltage and wattage. Nearest acceptable bulb was overrun slightly and thus died every 2 weeks or so. The default lamp was unacceptable at 4x1.2V
Computer widgets like cordless keyboards and mice: hopeless. Brand new cells weren't too bad, but after a few months, the cells needed recharging every week.
The only use I found them suited to were kids toys with motors.
I rather gave up after that. Wish they could invent a cell with at least
1.4V nominal...