You need to make sure all pick ups are isolated so your battery doesn't energize the track. Track power probably has pick ups on the loco too.
I don't know lgb, my info is generic.
I'd look online for a wiring schematic to see what I'm up against
His friend Jerry Dillon looked up at the hillside and said; There is a big ledge, and the whole damned hill is a total wreck with quartz boulders of ore.