Dead batteries

I am guessing you have the “HELLA 100A Rating Battery Master Switch” $18.00 from Amazon. For me I would be leery of a battery switch that goes for $16-18. On the Hella web site it says in reference to this switch “Note: Not suitable for areas exposed to water or moisture”. I am not sure it would fit but something like a Blue Sea Systems m-Series Mini Battery Switch would be something to look at.

Agreed also. Get a switch that is waterproof. Look at my mods for the one I use. It specifically says it is waterproof.

Thanks guys I was wondering if the gauge wire I use on the jumper could be a problem too. It is very thick. The batteries on these definitely get wet, I had one that the case drain sat on the tongue so that it couldn't drain and I went out and the battery case was full of water. I was considering making some kind of rain awning. Anyway I will not be such a cheapskate on my next switch

When dealing with battery's the larger the wire gauge the better, you will less voltage drop. Also drill some hole in the bottom of your battery box to allow the water that gets in to drain out.