Comment Distinction between blocking and difficulty (Score 1) 114
I recently bought a small spot-welder in addition to soldering iron. I have already used it to replace NiMH batteries for things like hair trimmer and those solar-powered garden lights. They use the pretty standard AA form factor, so cutting the wires, removing the old battery, soldering the wires to nickel strips and then soldering those to the battery are not too difficult.
Haven't tried to replace lithium battery cells yet, but should also be doable as long as the BMS stays intact and proper care is taken (be careful not to start a lithium fire...). I did replace a battery (that came with BMS included) on an old GPS navigator though (only needed solder), but that's of course a bit different.
Anyway, I've already encountered that even in those cheap lamps you can put in the garden there's clear difference (we have about a dozen of them, obtained at different times). The best one actually had a replaceable AA battery. The others I could replace with the procedure above. And some were just sunken in resin so that if you try to separate the components you are bound to break something.
In my opinion there's a big difference between "dump when battery dies" vs "can be fixed with not-too-costly tools at least if you take them to someone who knows what they are doing". Youtube is full of videos on how to fix your gear. And if you break it while learning then, well, the device was unusable anyway so it's not like you lost anything.
It's the "dump in resin" or similar crap that I hate to actively prevent DIY repairs.