[bradhaitsma]

Hopefully you have a little slack in that cable - if you cut off the broken end, there are replacement ends that can screw down onto the remaining cable....
Like this:

https://www.autozone.com/batteries-starting-and-charging/battery-terminal/p/duralast-top-post-battery-terminal-2-pack-dl06067/95964_0_0?spps.s=2633&cmpid=LIA:US:EN:AD:NL:1000000:BAC:8366688869&gclid=Cj0KCQjwof6WBhD4ARIsAOi65agDnKEbHaq_PbEWqGzoXDu7j0KGVZvN6_sqfdJbxgwJ4E0UxCSJTwEaAhCmEALw_wcB&gclsrc=aw.ds