Battery Question

Thanks, Old tyme flyr that is the set up that I would like to have. Thanks again

To RoyB I found the same blue sea isolator on Amazon for $79.00 So all I will need is number 4 battery cable and some battery connectors.Thanks again for the help.

Thank you for the advice. I will check into the Blue Sea isolator. In my 2007 GMC truck I already have another battery tray that was factory installed, so I thought that this would be the perfect place for a second battery, plus the truck would keep both batteries charged at all times. I do plug the TC into the 7 pin plug in the back, but I like the idea of having 3 batteries when boon-docking.

I put a second battery under the hood of our 2006 GMC. The battery tray comes from GM and was not that expensive maybe $30 (if the junk yard has a GM diesel, then you may be able to get the part for less). We are using the Blue Seas battery relay/isolator shown in RoyB's post.

We put the camper on and take it off at the drop of a hat (a lot.) I do not want to be disconnecting another battery and finding some place for it at a camp ground or have another battery at the house. In the truck its always ready for use.

Our camper, an Outfitter plugs into the trailer plug at the back of the truck. I am now in the process of doing the wiring. One of the steps I am undertaking is to remove the power wire from the fuse box and run it directly to the new second battery. The planning is done I just need to do it.

When I am done the truck will run off of the original battery and when the truck is running it charge the second battery and the batteries in the camper. The second battery will be available to the the camper at all times, once I remove the relay/isolator from the camper (also in RoyB's post-I could have used that relay by moving it to the truck, but chose to use the Blue Seas due to convenience.)

The Blue Seas relay/isolator in the truck will protect the trucks starting/running battery. We will then have three batteries to power the camper. If the truck starting battery needs a boost we would have to use jumper cables from the second battery to the truck battery although we could jump the Blue Seas relay/isolator with a short piece of cable.

Good luck.

I installed my 2nd battery in the truck bed, ahead of the driver's side wheel well. Much shorter cable than from the engine compartment. Check out the "Add-ons" part of my website (link below) to see a picture.

Excellent advice from RoyB. In summary, diode devices reduce the available charging voltage, and your camper battery(s) will never get a full charge.

This might offer you an additional option.

Tork-lift's Hidden Battery Box

I would be cautious on what type of BATTERY ISOLATER you purchase.

For charging deep cycle batteries you will need to be using 14.4VDC-13.6VDC-13.2VDC chargeing volatges and if your BATTERY ISOLATOR is a High Current DIODE based unit their internal voltage drop across the diodes will not be compatible with the required deep cycle battery charge voltages.

Make sure the BATTERY ISOLATOR is a smart solenoid relay item. Blue Sea and Sure Power Industries sell them on AMAZON...


The older DIODE BASED units look like this and will not work with deep cycle batteries.


These are just my observations...
Roy ken