I picked up a pair of 12v Trojan J185H-AC from a guy on kijiji. ( craigslist Canada)
He had bout them for a solar project that never happened.
He had dropped the price four times, I ended up paying $350 cdn for the pair. ( 250 usd).
Now I just need to find a place to put them.
The stock battery location has a cut out for a second battery.
The battery box is plastic and hangs below the basement a bit.
I am going to remove the plastic, and make a dual box that hangs a little lower, to fit the height of the Trojans.
I will have the welding class at school, bend up a box out of either aluminum or stainless.
Flanges will be wide enough to catch the lip on the frame rails.
Anyone else with a sabre, could easily drop another plastic box, and put another stock battery behind the first one. The metal is perforated for another cut out.
2016 Sabre 36QBOK
2015 Ram 3500 CUMMINS