Shrink Solder Sleeve Butt Connectors

These things are a boon to the ebike builder, so much easier than the tedious job of soldering many small wires, like when elimitnating clunky controller connectors. Even when working in a "rat's nest" of wires, one can use a directed flame torch and quickly make secure and weathertite splices without burning anything else. I'm ready to throw my soldering iron away!

They certainly can simplify some wiring, saving some steps.

Just beware that sometimes untinned wires don't solder properly with those.

Also, torches/flame may not be the best way for many people to shrink these; a heat gun can be better, especially if whoever is doing the work doesnt' have the experience to put the torch heat at sufficient distance to keep from damaging other wires in the bundle. The torch heat can be so concentrated that it can ignite the wiring insulation before one even realizes it's gotten that hot. The heat gun would generally be easier to keep from doing that.

I suppose if you have the room to make them fit....Have you used them yet?

Yeah, they worked great. On my Idrive build I used a controller and harness from another bike and the wires were a little short to reach my seat bag. I got them in thru a little hole I punched in the bag, but they weren't long enough to come out the zippered end, so I had a prob. soldering all the wires to the controller wires, so I just used sm. wire nuts. W/ these butt connectors, I was able to solder them together Inside the bag! As long as one wire has at least an inch exposed(the butt connectors can be trimmed), just slide the sleeve on and twist the wires together and slide to sleeve back over til the solder band is over the twist joint and focus a pin-point flame on the solder band. The sleeve is clear and it's easy to know when you are melting the solder w/out melting the shrink-fit. It makes a three-handed job(holding the iron in one hand, the solder in the other and somehow trying to keep the work steady) into a two-handed job(holding the torch and slowly rotating the work).
Every ebike tool kit should have an assortment of these.
https://www.gearbest.com/diy-parts-components/pp_009668199398.html?lkid=15477277

They sure are great, but I haven't found them at a reasonable price yet.
At $1 each, it becomes expensive in the long run (I build quite a lot of bikes)

Amazon has them for a slightly more reasonable cost. About $0.25 each. Splicing some 8-pin cables into 5-pin (display) and 2-pin (headlight) today. I'm borrowing a rad Hakko hot air station for doing these. I think a heat gun with a nozzle would work well too.

Thank you, I will go and take a look.