Not "knocking" any other brands, but I have used the Craftsman C3 19-volt system for 12 years now (not commercially, but I use them a lot). I have 13 of the tools (florescent & incandescent lights, radio, saws(3 different), drills(3 different), impact wrench (300 ft. lbs. torque), air compressor, hand vac, etc., 2 single chargers, & one 4-place charger/maintainer. (Wish I'd gotten the chain saw before they discontinued it, for the occasional piece of firewood that is too long to fit in our Earth Stove fireplace insert.) None of the tools has ever given me any trouble. Once the original batteries died, I bought the large lithium-ion batteries. 2 have lasted several years. Just got a 3rd with my new impact wrench, bought after 3 blowouts on our travel trailer, 2 on the way to get rid of the Chinese tires that came with our 2016 Rockwood. I am disabled, and it's hard for me to "break" the lug nuts. I have to use sockets on our trailer, anyway, because a 4-way & most other lug wrenches will not fit in between the spokes of the fancy aluminum wheels on our new trailer.