About that battery...
I cut the bottom of the additional battery cage under the rear left wheel fender in two places on the bottom. I bent it straight, then bent it again at 90 degrees to make a bigger area for a new battery.
I replaced the short retainer plate bolts with longer ones. The nuts are the nylon locker nuts.
Starts much better now. But I also use the booster pack for cold starts and usually prop it up on a 1 gal paint can to let the back wheels turn freely on start up until it gets hot. After that, it starts fine if I stall it or something.
This little Hummer is loads of fun for my 5yr old and me. We ride tandem with him in front.
...and yes, we broke off the chain guard already.