Attaching Cables to FRC Batteries

[Tristan Lall]

Personally, I prefer to use the supplied hardware, especially on the battery terminals with the groove that retains the fastener across its flats. I tighten it securely (using a wrench—not a Phillips screwdriver, which could cam out—to estimate adequate preload in the bolt) with a small drop of purple Loctite (low-strength, 222MS), which I take care not to apply to the plastic parts. If the fasteners can't spin, they can't come loose.

I find that it's also important to use the right-sized lugs. The Ø0.250 in lugs that FIRST has supplied in the past work fine on the main breaker and power distribution board, but they tend to slide around on the battery. I buy ones sized for a #10 screw instead. (These sit a little lower on the terminal, and thus can't rotate about the screw because of the edge of the lug in contact with the battery case. That has the advantage of preventing rotation—and loosening—as well.)