What's this, some kind of new kind of device for keeping your pennies organized?
Nope, it's just the holddown strap for the battery. I cut the optional lightening holes to take away some of the mass of that hefty alunimum bar, and painted it to match the battery box just because I felt like it.
Down below, the input side of the starter relay is now connected to the output side of the master relay via a copper bus bar.
Interestingly, the prescribed mounting orientation for the starter relay is such that positive G forces will tend to open the relay instead of forcing it closed – there's a note in the plans about this. I guess they are concerned that the starter might kick in at the bottom of a loop?