very nice but you can reduce some of the load if you swap that battery for a lawn mower one for half the weight and size of the car battery but still have power to last running the pump for days if its a weekend excursion. nothing better then putting unused stuff to a new and more useful purpose.
if you fill up the box with trout, that's a lot of weight in front of the wheels so I can see it might be out of balance but that would be a very nice problem to have