I have an 18 V Makita drill/driver made in 1996 or thereabouts. I'm just a hobbyist, so it gets used only about once a month. Came with 2 x model 1822 NiCd battery packs. One died a couple of years ago (won't charge, still have it) and the other is getting very weak: last night with a "full"charge I drilled and countersunk about 15 1/8" holes in a 3/4" maple ply tabletop and matching pilot holes in hard fir legs, and the battery pooped out halfway through driving the screws.
The driver seems to be in good shape, so I'd prefer to replace just the battery. On Amazon, I see a Makita 193159-1 1834 18-Volt 2.6 Amp Hour NiMH which appears to be a compatible replacement. Are those current production, or is that an old model that's been warehoused for years? If I'm not mistaken, NiMH batteries don't last forever in storage, so if those were made long ago, that may not be great. Anyone bought one of these recently with good results?
There is also a aftermarket brand "Expert Power" NiMH available. I've had terrible results with aftermarket Li-ion digital camera batteries (about 1/4th the capacity of original battery), so I'm wary of this. Can these be trusted?