Best practice is a fuse as close to the battery as practical. If you don't screw something up, you'll never need it. If you screw something up, it protects your battery from shorting out.
-If you screw up once, replace the fuse and go on.
-If you screw up twice, replace the fuse and start examining your life choices concerning your actions around dangerous objects.
-If you screw up 3 times, High voltage toys probably aren't for you.
-If you screw up so many times that a circuit breaker is worth the cost/effort, you probably don't need to be using tools or be left alone around sharp objects
You need a fuse sized on the max amps of your controller, plus a little extra. So if you have a 20 amp controller, I would get a 25 or 30 amp fuse. While I use automotive blade fuses, there is an arcing risk, so a proper high voltage fuse is right answer. Check Amazon or Ebay for "FKS 80V 30A" fuses, or what ever amperage you need. Get at least 2