Big truck battery isolation

[Tontoou812]

I have a Webesto heater in my Freightliner that burns diesel fuel and has a 12v fan to circulate the warm air. I want to connect it to a separate battery from the 4 that operate the truck but also be able to charge it during the day when the engine is running. I would run a ground to the ground side on my battery pack but run the positive side thru a switch or breaker. It needs to be weather proof and fairly inexpensive and able to handle a 4 gauge wire. Any ideas? Thanks

 

[herm0016]

if you want it to be automatic, check this out. http://www.expeditionportal.com/forum/forums/48-Power-Systems-12v-Solar-Gen

if not, just a marine battery switch should work fine.

 

[Tontoou812]

Thanks. Checking into the marine switches