Second battery installation questions

[RonPH]

Hello All,

 

I am new to this forum so please bear with me. I am contemplating on installing a second battery mainly to be used in camping and not for audio equipment. I own a GMC Sierra 1500 and no room in the engine compartment for a 2nd battery so I will be installing it on the back of the truck. The 2nd battery will be used only when the engine is off and I have already purchased a VSR Relay 125AMP and a battery box (no battery yet and wiring) as I need some feedback from the members.

 

First, would a 6AWG work for this setup running around 10 to 12 feet toward the back of my truck.

Second, my alternator is stock and wonder if it will not be overworked charging a second battery.

Third, I read that a fuse is recommended and should be placed as close as possible to the positive side of the both battery terminals. My thoughts are that I would install a Littelfuse ~125 AMP circuit breaker from the positive side of the main battery and then to the Relay Switch (VSR). That way if I DO NOT need to charge the 2nd battery, I can just disconnect it through the circuit breaker so it serves two functions - fuse and quick disconnect so no power goes into the relay. On the second battery, I will be also placing a fuse for safety reasons (and is also recommended). As for the ground side of the 2nd battery, I will just be grounding it to the chasis/body of the truck closest to the 2nd battery as possible. The second battery would be the same specifications as the main battery.

 

I am aware that there is a voltage loss but my purpose is just to maintain or top-off the second battery. No appliance will be connected (to the 2nd battery) while the engine is running.

 

Thanks

 

Ron