Multiple (3) Batteries setups

[Tkdx00]

Folks,

I'm currently installing a second battery to handle secondary items (lights, winch, OBA...etc.). I have both the Blue Sea manual and the IBS Battery Management systems. Down the road I plan to finish my ExPo trailer which has it's own battery.

My question is, in order to have the 1 alternator work best for the 3 batteries, and the 2nd battery will NOT be under the hood, which switch should be used to connect to the main battery now? I keep going back and forth on the pros and cons of either. So I need some expert advice.

Thanks for your input.

 

[dwh]

There is no best really. It's just another battery being charged by the system.

Is there a hot wire in a 7-pin trailer plug? That'll charge the battery, but from what I gather it's usually not isolated so you'll need to unplug the trailer to isolate. Better to isolate that wire automatically if you ask me.

You can use any number of automated battery management systems or split-relay solenoids tapped off the main battery or manual switches if you want. One for the aux under the hood, another for the hot feeding back to the trailer battery.

Personally, I'd just use a couple ignition energized dumb solenoids (cheap 50 dollar isolator thread) - one for each aux battery.

 

[Tkdx00]

Currently I don't have any trailer wiring installed. That'll come later.
I figured by using the Blue Sea manual switch on the primary, I can keep it on the 1 position to keep the main battery charged. Then the 1+2 position when I need the 2nd battery charged. Then by using the IBS system switch allow it to keep the 2nd and 3rd batteries charged when I get the 3rd battery installed when the Blue Sea switch is in the 1+2 position.

 

[Scoutn79]

To isolate your trailer battery from your vehicle when the trailer connector is connected I wire in a 40 amp relay. The relay is activated by the key on run position.
This way when you turn off the truck/ or are in the ACC position the trailer isn't connected but as soon as you start the engine the relay connects and charges the trailer. I run a 10 ga wire to control the battery charging to the trailer.
Darell

 

[Tkdx00]

Everyone, please forgive my OP. I knew nothing about this subject and did not do proper research before I posted. Although the responses did push me to find what I was looking for so for that thx. I confused the hardware for USING a dual battery set up with CHARGING a dual battery setup. The Blue Sea switch I bought mistakenly is for USING the batteries, I would need to buy an additional part #7712 for the CHARGING side. I already have the IBS Battery Management system from TJM for both.

Thx Scoutn79...that sounds like a plan.