Just wanted to show how I'm making my own cables for interconnecting the batteries, motor & controller. I use welding cable from a local welders supply (Usually get short scraps very cheap), and then buy copper couplings (used to solder copper pipe together) from the local hardware store @ 35cents each.
1. Cut cable to length needed and strip both ends just enough that the copper couplings slip over the wires.
2. Hammer the copper coupling flat onto the exposed wire, which spreads out the copper wires evenly throughout the copper coupling.
3. Solder the coupling/wires
4. Drill the copper coupling with the proper hole that is needed per application it is being used in after soldering.
5. Grind the ends round if preferred, apply heatshrink tubing to dress them up, buff the ends nice and shiny.
Below is a photo, just before heatshrinking, drilling holes, grinding the ends round, and finally buffing them out.
The other photo was my inspiration to making my own cable ends, these silverplated copper straps were included with my Hawker batteries.
NOTE: Excuse the sloppy soldering, I was low on butane in my little torch.