Earth/Ground/Negative

Hi, I have a Warwick XL 2021, I'm trying to find an additional chassis earth point for the habitation battery, fitting additional isolated B2B and the present negative cable coming off the battery is a bit light, so wanting to beef it up but would prefer not to drill holes in the floor, my previous Elddis had so many holes it was never a problem :) So any neat ways to get higher capacity earth to the hab battery, please. Cheers in advance Kevin

Seems I have answered my own question, Eventually, I took the Sargent unit out from under the wardrobe, further back in the underutilised cabinet is the drain from the bathroom which has space to push down the cable.