I have a Grandby on order and am planning a lithium battery installation (and associated charger changes and solar panels) immediately after delivery. I wanted to see if I could fit two Battleborn 100Ah batteries in the compartment, so I went to my dealer's showroom (Mule Outfitters) to measure the battery compartment of a 2020 Grandby slide-in front dinette they have there.
I thought others might find the information useful so I am posting it. The dimensions should be the same for a Hawk front dinette because the cabinetry is the same between those two models according to the dealer.
North-South dimension is 22 inches (part of the enclosure extends a couple inches further North, but is useless for battery installation purposes), East-West dimension is 9.5 inches, top to bottom is 19.5 inches. The camper I measured had the Chevy notch, and the floor of the battery compartment was raised so only about 1/2 inch of the floor was lost along the West side to the angled notch (hopefully that's clear). (Update: in the Southeast corner of the compartment (just inside the door to the left) there are multiple wire bundles that take up 2x2 inches from the bottom to the top.)
The Battleborn 100Ah battery is 12.75"Lx6.875"Wx9"H, so two won't fit if installed in the conventional orientation with the connections on the top. However, the Battleborn manual says the battery can be installed in any orientation. It appears I could fit 2 installed on their ends with the terminals facing each other. The door opening dimensions are 16.5 W x 17.5 H, so getting them through the door should be no problem. I'll figure out how to secure them once I actually have the camper and batteries.
Anything I'm failing to consider here as far as physically fitting and wiring up two BB 100Ah batteries in that compartment? I know if I install the batteries with the connections facing the door the space will be tight for the wire connections, but I suspect that could be addressed safely. The area of the door opening adds another 1/2 inch to the East-West dimension because the door is face-mounted, which would give some extra room for wiring. I suspect I'll install the other way with the "tops" of the batteries facing each other, so there will be plenty of room for wiring and the wiring will be better protected.
Edited by Jon R, 14 February 2021 - 06:16 AM.