Recommendations for managing battery/fridge when towing

Roamey

I added a second battery under the hood. 

dsatwork

Roamey said:

I added a second battery under the hood. 

WOW you sure did....what is the TV?

Roamey

2012 Frontier V6. (no turbo chargers in the way)

dsatwork

Roamey said:

2012 Frontier V6. (no turbo chargers in the way)

It's nice to have the extra space in there. It's very Outback-esque  to have two under the hood. No way in my 2016 Kia Sorento. So I put my 35AH AGM auxiliary battery on the floor behind the seat, on my last trip. I'll tap into the 80AH AGM starting battery, before we head out to Joshua Tree, the first week of December. I'll bring the 35AH backup power supply too, but only as an option, if needed.

Sharon_is_SAM

I think we need to vote on this one!  Better yet, how about a multiple choice test question or a poll...(So the manual is incorrect after all?)  

The Tab battery cut off switch in the OFF position results in:

A)  no power is being delivered to the Tab battery from the TV 7 pin and the Tab 12 volt system is isolated from the Tab battery.  Nothing going in and nothing going out.

  power is being delivered to the Tab battery from the TV 7 pin, but the Tab 12 volt system is isolated from the Tab battery.  

C)  if A then don't eat the egg salad that's in the Norcold on 12 V.

D)  if B then better get a good set of jumper cables, cause you won't be leaving that restaurant that you stopped at for lunch any time soon.  

D)  None of the above.  Ever heard of dry camping?

Thank you Scott for the logic.  I have questioned the entry of the cut off switch.  Not that I have any experience, but in my readings the breakaway brakes are supposed to be the first line off the battery before the cut off switch.  And yes, not good re the breakaway brakes if you forget to turn the switch ON.  Having said all this, our new mantra is - only use the cut off switch when we store the T@B.  So much easier to just remember one thing:)

Sorry, but I can't get rid of that smiley face where letter B should be....

ScottG

This graphic might help in understanding how the T@B's 12V supply is wired. This is the distribution box under the front of the trailer. The various positive lines are labelled, and all join together at the second terminal from the right. (A similar arrangement is seen with the negative lines on the rightmost terminal.)

My understanding is that stock shut-off switches are installed in the tub on the positive line leading to the battery. Some DIY's have alternatively installed the shut-off under the bench on the positive line leading to the converter.

You might think of it as four spokes radiating from a central hub (the distribution box). If you think of it this way, you can see the implications of having your shut-off installed in one location vs. another.

USUAL DISCLAIMER: This is from my 2015. I make no guarantee that other trailers--even those within the same model year--are wired in exactly the same way. Always check and confirm your own configuration before attempting any modifications.

 

Sharon_is_SAM

So, for the record, our Sienna has an after market hitch and 7 pin.  The 7 pin charge line is still active when the ignition is off.  So, if we stop for any length of time with the frig running, we disconnect the 7 pin.  I am guessing it would drain the TaB battery before the TV battery, but not sure about that.  Anybody know?

ScottG

In that particular situation the fridge would still be effectively hooked up to both batteries. I don't know what factors (if any) would determine which battery would drain first, but I'd keep doing what you are doing and not tempt fate. Even though you can always get a jump start, automotive batteries do not tolerate being deep-cycled very often, and doing so will shorten their life considerably.