So get one of these instead of a battery and another charger, and disconnect the Triad's red wire from the fuse panel and the white wire from ground. Note this converter cost is about the same as a battery's and no shipping cost it says.
Now run a wire from the positive terminal of this converter to the fuse panel to where the Triad's went, and a wire from its negative terminal to that ground connection the Triad used. #8 wire would be ok.
https://www.boatandrvaccessories.com/products/powermax-pm3-45lk-45-amp-12-volt-power-supply-with-led-light
