I just rebuilt a lithium ion pack on my parents dustbuster (handheld cordless vacuum), they loved that thing but it was down to only a few minutes of battery li

I just rebuilt a lithium ion pack on my parents dustbuster (handheld cordless vacuum), they loved that thing but it was down to only a few minutes of battery life. Black & Decker refuses to sell replacement packs, and once you open one of the packs up it's easy to see why. All the brains of the vac are on the controller board on the battery pack. The rest is really just plastic, a switch, and a motor. My guess is the replacement cost of a pack would be about the same as a whole new unit, so they just don't make them for it. I bought a cheap spot welder ago on Amazon some years ago for re-celling packs. I bought the highest rated high output Molicel 18650's and it took about 5 minutes to spot weld them in with some nickel. Vac is now better than new, runs for a half hour or more on a charge. Probably will be good for years unless something else breaks in it.