I rarely buy new packs, if one wears out and I can't find a decently priced one, I build it out myself.
I see them as a challenge
to keep me on my toes.
The harder ones are the not so obvious safety keys built in holders. B&D has them in their 18V packs , so I just remove old batteries ( drop off at recycler) then use the hull as adapter. I've done this for our weed whacker. Instead of 1.8Ahr at 18Vdc I wired up 3 and use their better slow (recharge at 9hr ) charger to blend the packs. 18ga multi-strand extension cord allows me to have them on a ARMY web belt
.
Old drills, 9.6 up to 12V I just bring wires out to battery attachment.
I'm waiting for norm to post a pic of his E-Cane
Cheers;
Bruce S