Make sure your battery can be tightened down by the bracket to secure it in place. I suppose it depends on law enforcement in your area, but they will probably check to see that your battery is secure if they ever board your boat. On Milwaukee Harbor, I've been boarded by the Coast Guard and they check for this.
BTW, with the Coast Guard, they boarded our boat and once aboard they looked at everything. The rest of the group of Coast Guardsmen who didn't board our Epic were on their gunwale to watch the inspection. They ooh'd and ahh'd like is was the 4th of July when they checked the engine compartment and got a glimpse of the engine, which the guys aboard checked for the spark arrester. This was the first time they had seen an Epic, so they took a really close look at everything on their check list. The battery tie-down was at the top of their list.