This reply is not directly related to OP but thought I would let you know what I did on my coach. After disassembling the battery slide, I had the components sand blasted and then powder coated. This process is a little pricey but seems to have worked very well. I did this several years ago and was able to use rustoleum on the surrounding area. At the time, I was unaware of POR.
2014 Newmar DSDP 4018-450