Dual battery for dummies - National Luna install (1 Viewer)

[sundaypunch]

I figured I'd post a thread here with some pic's & details. Hopefully it will save other electrical novices like myself some time.

I wanted to go with a dual battery setup as I'm adding an Engel fridge in the back. A winch is also planned later this year. I wanted the simplest install due to my limited electrical knowledge. After reading through all of the dual battery threads about a dozen times each I decided to go with the National Luna system. The only downside seemed to be the $375 price tag. After pricing cable at West Marine (almost $4/ft. for 6 ga) the price didn't seem so bad considering it comes with 40' of slightly heavier cable as well as the "intelligent solenoid", controller, connetctors, etc. The kit is complete, the only thing I chose to buy was some heat shrink and split loom.

On a side note, the cable supplied is 16mm2 gauge. This converts to 5ga. AWG-
AWG - metric conversion table


My first step was to install a Slee washer bottle relocation kit and battery tray from a '91 LC. Installing the NL system was very straightforward. I did steal many of my install ideas from a few threads-

https://forum.ih8mud.com/80-series-tech/175892-national-luna-dual-battery-install.html

https://forum.ih8mud.com/80-series-tech/220528-who-has-national-luna-dual-battery-setup.html

National Luna Dual battery install - Expedition Portal Forums

The entire install consists of-

-Mount the intelligent solenoid
-Run a fused hot wire from the solenoid to each battery
-Run a ground wire between the batteries
-Run the controller cable from the solenoid into the cab.
-Connect a ground wire from the solenoid to the aux. battery
-Plug in the controller to the solenoid

Here is a schematic - simple.

 

[sundaypunch]

I mounted the brain (intelligent solenoid) to the back of the aux. battery tray-

In position-

The hot wire from the solenoid to the aux. battery gets a 50-amp fuse-

 

[sundaypunch]

The hot wire from the solenoid to the main battery gets a 100-amp fuse. I ran this wire under the aux. battery tray and under the crossbar near the top of the radiator. I protected this with split loom when I finished the install-

Wire coming thru on the drivers side-

To the 100-amp fuse I mounted inside the fender. The cable will go from this to the pos. terminal on the main battery-

 

[sundaypunch]

The controller gets mounted in the cab. This is where I passed the black wire through the firewall to get it into the cab. (the two red wires are to my two 12v circuits in the back)-

Here is the wire as I brought it into the cab. You need to reach up as high as you can on the firewall to fish it out-

Drop the glovebox and route it up behind the ashtray-

Route the connector into the ashtray opening-

 

[sundaypunch]

As you probably guessed I am mounting the controller in the ashtray. Easy to access when I need it but out of sight most of the time.

Notch the back of the ashtray-

Controller in the ashtray-

I left plenty of cable so that I can remove the controller and hold it by the steering wheel if I want to change some of the settings-

 

[sundaypunch]

I ran the 5ga. ground wire in front of the radiator to connect the two negative terminals on the batteries. The only other connection was the small ground wire from the solenoid to the aux. battery negative post. They say to do this connection last and the unit will blink once to signal all is well.

I went with Sears Platinums for the batteries. A series 34 for the main and 34M (marine) for the aux. That was another few days of reading.....

The only downside with the Platinums is that the terminals are reversed. I ended up flipping them around for two reasons. First, the battery hold down brackets were too close to the terminals for comfort. Second, there was no way to get the existing wires on the main battery all the way to the front without getting creative (the fusible link & other junk on the positive side couldn't easily be pulled through the opening in the tray).

Here's a pic. of it completed. The kit makes for a clean install-

Drivers side. Just a cable to each battery post-

I had plenty of 5ga. left in the kit to go from the battery to firewall. I went from the aux. positive post to a 40-amp fuse block that I bought at West Marine. This goes to a fuse block on the firewall (currently with two 15-amp fuses feeding receptacles in the rear)-

 

[sundaypunch]

Overall I'm very happy with the install. My wallet is about $1000 lighter after buying the batteries, kit, and misc. stuff for my rear outlets. There are cheaper options out there but if you are like me an not up to speed on electrical stuff it is a good solution.

 

[TOY350]

I'm looking to go this route as well. Nice pics and write up. The only drawback is that you can't run the inline fuses with a winch. I talked with Steve (the manufacturer) and he told me not to run the fuses because of the load created by the winch and the only reason for the fuses is to protect the system if you were to short it out by having a contact come in contact with metal. So just make sure your conacts and a very secure and all should be fine.

 

[sundaypunch]

The manual shows a configuration with a winch. It does say to leave it unfused. I think what I will do at that time is just remove the fuse and connect both terminals on the same post.

 

[NLXTACY]

Hmm, maybe you can just run a selector to switch from fused to non-fused quickly instead of running jumpers or such