Hold it down and hold on to your butt.
Having your battery fly out of your ride is a full on “aww S*#!” moment. Covering more of the sides and a lightweight strap across the top makes a snug fit. Some physics nerd will tell you that moving the weight to the sides and lower is better for lowering your CG. I’d rather just know I’m not gonna lose a bullet connector when I miss the triple and plow into the base of the jump.