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mikegraef

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Hi all - this is my first long post since joining several years ago. Thank you all for the ideas, the guidance and support you all show - it's awesome to learn from others and get help from actual owners who have done repairs or projects and can offer advice to make it easier for others. That's my intent here.

I did this project back in August 2018. I did several projects that fall and just never got around to posting them! For the first project I Iinstalled a National Luna Dual Battery in my 2012 LR4. I enjoy offroading/camping and really like the idea of having a backup source of battery power - whether for lights/accessories or just in case... After doing a bit of research on the pros and cons of the systems available I settled on the National Luna Dual battery controller from FrontRunner Outfitters. While not the least expensive I find they have good quality and their customer service and delivery have been great on the 5 or 6 orders I've placed with them.

As part of this install I decided to also re-wire my power outlets and add additional outlets in the rig, all wired to the 2nd battery. My logic was that when camping or offroading there are times you want to leave something plugged in and charging or running without having the engine on. Or worse, having the ignition on, but the engine not running, and your accessories or charging shut down when the primary power automatically times out and shuts off. I'll document that project in a future post on the topic.

I also wanted to prep for adding a winch to my rig, and while the power for that comes off the primary battery I saw that as another potential issue for primary battery power being available when you need it. Bottom line - a second battery seemed like cheap insurance when off the road, and besides, it would be a chance to tweak my rig and get started with updates to make it a viable overlanding rig!

At the time my wife and I shared this truck as our daily driver, so I could only tie up the truck for so long. I work from home most of the time so the single car worked fine for us. For this project I decided to start on a Friday evening, giving me all day Saturday and into Sunday if needed to complete the work. In total I think it took me about 7 hours. With a guide, and not taking gloves on and off constantly for photos I think you could complete this project in about 3-4 hours. A great Saturday or Sunday project for sure!

Things I bought for this project:

National Luna DIY Split Charge kit from FrontFrontRunner Outfitters - $349
https://www.frontrunneroutfitters.c...ational-luna-diy-split-charge-system-kit.html

Per their product listing:
The National Luna DIY kit is a collection of all the parts you will need to complete a typical dual-battery installation (excluding battery). The kit includes cable, lugs, screws and other parts which are typically used in dual-battery systems. A full instruction booklet is included in the kit for easy reference.

Simple installation includes:
  • Dual-battery isolator (Intelligent solenoid)
  • Dual battery controller
  • 12-metres heavy-duty cable
  • In-line power fuses
  • Accessory fuse
  • Cable lugs
  • Battery terminals
  • Screws
  • Cable ties
  • Instruction manual
  • Picture is from another site since this was higher quality than the small file shown on FRO.
X11889-National-Luna-Battery-Management-System-complete-kit-800x600-02.jpg


Next thing I needed was a battery. I selected the Optima Yellow Top AGM D34/78. I read lots of feedback and opinions on the Oddessy and the Optima, but in the end it seemed like the only issue folks had with the Optima was the cost. Like most things everyone has a personal experience that shapes their opinion, so since I live close to an Off Road Warehouse location I picked up my battery there.

Optima High-Performance AGM Battery - model D34/78 from Amazon (ORW not showing them as being carried on their website) $265.

https://www.amazon.com/Optima-Batte...hvlocphy=&hvtargid=pla-4584345016065931&psc=1

Optima battery.jpg


Those were the two big items I needed to purchase for this install. In addition to the kit and the battery I loaded up on a variety of small zip ties (4" and 8"), heat shrink tubing to go over butt splicers, heat shrink butt splices, various sizes of cable and terminals for my battery. I won't list all those parts here, but for the most part I used Amazon with 1 or 2 day shipping. Everyone has a favorite way to do this, but note that you will need a variety of connectors and wraps before the project is complete, so it's worth spending a few bucks getting everything you think you might need - up front - instead of realizing at 11:30 at night that you can't finish your project! Not that it happened to me (at least not more than 2 or 3 times!) 8-}

With the 2 key pieces of kit in hand I was ready to start the project. The general idea is that by installing a second battery and the National Luna DIY Dual Battery kit I would add the ability to self jump-start if needed (see instructions for this in the National Luna documentation) as well as add a deep-cycle battery to be used for accessories, lighting, etc without the fear of overtaxing my primary battery and finding myself unable to restart the vehicles miles from help.

In the 2012 LR4 NAS (North America version of the vehicle with 5.0L V8) there are two battery bays. The primary battery bay is on the passenger side, and houses the primary battery for the vehicle. The second battery bay is on the driver side of the vehicle.

In many vehicles that shut off the engine at a stop sign to reduce emissions and increase fuel mileage they actually have a second battery installed. This ensures that even with the constant starting/stopping of the engine while in traffic the vehicle will still be able to start reliably. My vehicle was not configured that way, and does not shut off when I am idling at a stop light. I'd like to think JLR believes these vehicles need the 2nd battery bay for just the sort of overlanding I want to do, but I don't know that for sure. Maybe someone else does?

Regardless, I had a second battery bay, a mirror image of the one on the passenger side, except that in my 2012 LR4 that second battery bay was occupied with an ECU, housed inside a plastic shroud, along with the horn, Break fluid reservoir and a collection of brake lines. I don't recall what the ECU unit does, but on another thread a user confirmed it's purpose and that they had successfully moved it outside the bay. Here's a picture of the second battery bay and what was inside:

2nd battery bay 2012 lr4.jpg
2nd battery bay 2012 lr4 - inside before.jpg


Another member had posted about removing the plastic cover and moving the ECU to the right, under the break lines and below the horn (far right side of the picture). With that thread as my inspiration and rough guide I got started. My goal here is to provide more pictures and a bit more detail on how I completed this project.

With the 2nd bay exposed I removed the plastic shroud covering the ECU and removed the horn from under the break lines. A nice extension and magnetic inserts to your sockets (or a flexible tool to grab fallen parts is helpful.

See this link for inexpensive tool to grab small parts that fall into places you can't reach - https://www.amazon.com/Grabber-flex...hvlocphy=&hvtargid=pla-4583726541131886&psc=1


The system will only allow 5 pictures to be uploaded, so I will start a Part 2.

See this same thread - part 2 for continued instructions!

Thanks
 

SantaAna7

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Greenville, SC
Thanks for this series Mike! Really appreciate the details. Looking forward to how you modded your outlets and any fuse/wiring work. I think you're encouraging me just enough to be dangerous.
 

toddjb122

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...The system will only allow 5 pictures to be uploaded, so I will start a Part 2.

See this same thread - part 2 for continued instructions!

Thanks
I'm on the edge of my seat!!! Where is PART 2??? :)

This is one of the key mods I have wanted to make since I've had an LR3 in 2005 and now and LR4. I was disappointed to see they 2nd battery box occupied in the LR4 and I'm not that comfortable in the engine compartment moving brake lines around and such... so curious to see your approach.

Thanks for taking the time to write this up.
 

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