I have wasted a few of the lead plare/ acid type batterys. It was becouse the batterys were flailing about, and becouse of the shock the batterys were given on hard bumps, or bounces. This lead to one of the cells in the battery going bad, and the battery not holding or taking an adequate charge. The lead plates just don't seem to stay intact long term, when in abusive conditions. I then when to an optima, and now a gel filled battery, which is a cross between a optima, and an oldschool, lead, and acid, type battery.
My current battery tray is an angle iron frame, welded to the factory location, with a small brace/clamp type pice on each side, to prevent it from sliding in any direction, or floping up, or down.
