With stuff like this one could go old school on it. In this case old school like the electric utility guys make up service laterals to your overhead on your house with split bolts. Start with a wrap of self fusing rubber tape and do a 1/2 overlap. Don't forget to give it a bit of a stretch as you wind it so it fuses well. Go over that with a premium heavy duty tape like Super 88 once again 1/2 overlap at least. Finish it off with friction tape for abrasion and UV resistance. If it works on houses for 50 years it's probably good enough.
If you want more modern and neat then the heat shrink idea is great. Most factory stuff is done this way these days. The newer heavy duty polyfin tubing is amazing and exudes a waterproof plastic on the inside when it melts. You can see it make a little bead on the ends. I crimp my own battery cables (have the tools from doing off grid power installs) and do all my battery stuff this way. Use copper lugs in the right gauge, a really good crimper, then heavy wall polyfin and it's a one and done deal.