In July I replaced my 10 year old breakaway battery. Yesterday I was replacing the impossibly stuffed junction box with a nifty 3d printed one with a terminal strip in it, and removed the breakaway box to bet better drill access. Tonight I thought I should put the thing on a real charger, but I couldn't figure out the polarity of the plug (black and white wires vs black and red, and white was ground on other parts of the trailer)
Opened the box and the positive terminal had snapped off down inside the battery.
So, in addition to a new battery, I'll be putting a large dollop of glue on the terminals and securing the wires after hookup.