Originally Posted by sherrylynne
So...it appears the compartment that holds the two batteries is almost rusted through. My son said he can "weld-up" a new box and install it. I wonder if this is the best route? Is there a fiberglass or hard plastic "box" that might be a better idea? Thanks for your help.
Well, the problem is the converter, and the fact that you're in Florida. The corrosion is just a symptom.
Here's the deal. In hot weather, batteries are prone to overcharging, and the only way to prevent it is to get a 12v
converter/charger that has a temperature sensor that goes in the battery compartment. The converter/charger then reduces the voltage as temperature goes up. When batteries are overcharged, they tend to spill electrolyte out the vents, which is corrosive, and causes the damage you see. In Florida and other places where it gets hot this sort of thing is a real problem, especially if the trailer is left plugged in most of the time.
How to fix it is up to you. You can get a good temperature compensated converter, and then fix the battery box using the material of your choice -- painted steel will last a reasonably long time then. Or you can find or make a noncorrosive plastic battery box that will fit the space and be strong enough to handle a hundred pounds of batteries on a bumpy road, which you may find to be surprisingly difficult.
Or you can just follow your son's advice and weld it up, and figure it will be good for another 5-10 years.