Numax told me that wpf window cleaners abuse their batteries by the sheer nature of their work. They refuse to give a warranty on any battery used by a window cleaner as they estimate that our batteries only last about 6 months. Warranty will always exclude customer abuse or using a product for a job it wasn't designed to do. (If it went to court, how do you prove that their product they sold you wasn't fit for purpose? @SPC although it should really be their having to prove that you didn't look after it rather than you having to prove you did. (Where is the "old innocent until proved guilty" aspect gone?)
I didn't do too well with leisure batteries when I had my trailer. I often wondered if it was because it was fixed to the draw bar and exposed to the elements. It was charged with a split charge relay from my Suzuki Van which was wired up through the 2nd tow bar electric socket.
Good idea,
