Adding aux battery in bed

[hunterdan]

I have a battery mounted in the bed of my truck to run a small winch for loading deer and other stuff into the bed. Worked great last year just running off the spare battery (not tied into the truck at all). However, I hadn't had a charger on it for several months and the battery is dead and won't hold a charge. So, a new battery is in order. But, I want to connect the battery to the trucks charging system to keep it topped off and good for use year round. Ideally, I'd like to do this as cheap as possible, without dumping a ton of money into it. But if it gets to be expensive, the next option would be a solar charger of sorts. I figure I'll need an isolator, but what guage wiring do I need to run from the stock battery location to the aux battery? Can I get away with 10 guage or do I need to go to something larger?

 

[SitKneelBend]

Just a thought, but some Ram Heavy Duty Trucks come with a second battery on the passenger side of the engine bay. Maybe it might be worth looking possibly adding this for your application.

Honest question though, why not just run the winch off your truck battery? You can put a larger battery in fairly easy too in the stock location.

 

[dlromo]

Or run a maintainer on a deep cycle?

 

[mgood13]

Could also run off 7 pin trailer wiring aux+ And tie it into battery in bed. Use a dc-dc charger or battery isolator

 

[Brian2081]

Ok, second battery on some HD's is for diesel applications, unless you remove stock air intake and replace with aftermarket CAI. If you use the trucks alternator you will need the isolator. Not sure what gauge wire comes from the alt to charge the batt, but you will need the same size if not a little bigger because of the distance from the alt to spare batt.
As for the seven pin, I personally would not use the power wire to charge the batt, not big enough for the possable high amp draw, melt that wire and high chance of fire.