Dual battery setup in 1997 4runner

Hello all,

Over the last few weeks we have been reading up on how to install two deep cycle batteries in a 1997 4Runner, we mostly got all the information from this forum, so Kudos to everyone who has posted their detailed photos and step by step instructions.

Here is a series of photos of how we did it. Note that we are still waiting for The National Luna Intelligent solenoid, so we will post the wiring photos as soon as we have that up and running.

What we used:
  • Optima Dual Battery Box from RuffStuff
  • Optimal Yellow top 34, and secondary battery
  • Optima Red top 34/78, as starter battery
  • Overflow reservoir pipe - roughly a foot and a half
  • 1985 Toyota Overflow reservoir -smaller than the stock overflow reservoir on the 1997
  • Some Teflon spacers to support the batteries (not shown in photos, forgot to take the photos)
  • 4 x 8m 3.5inch Bolts, nuts and lock washers
  • a can of Engine enamel to stop the box from rusting (it rusts quickly, and is not treated when you receive it.)
Two Optima's and a Dual battery case
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3882-yellow-top-red-top-battery-case.jpg


What they look like in the tray before it was painted - note the start of rust one week after arrival.
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3883-two-optimas-new-battery-case.jpg


Stock battery removed - note the battery mount and fuze mount is still in place
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3884-removed-stock-battery.jpg


From a different angle - note the over flow bottle, that needs to move
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3885-closeup-battery-area-radiator-overflow-bottle.jpg


Cut made to plastic cover on radiator - we used a dremel tool to make the cuts and left the mounting bolts in place for added support, note the overflow bottle is gone
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3886-cut-part-radiator-cover.jpg


we removed the fuse box bracket and cut out the original battery mount bracket
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3887-cut-battery-clamp-bracket-cut-fuse-box-mount-both-plastic-metal.jpg


Dual batteries in the new tray installed.
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3888-installed-batteries.jpg


made a custom bracket for the overflow bottle - the stock bottle is too big so we used a overflow bottle from a 1985 Toyota pickup it fit perfectly and does not touch or rub against any other parts
kobusliferemotely-albums-1997+4runner+dual+battery+setup-picture3889-new-position-radiator-overflow-bottle.jpg


Again thanks for all the advice, We will post the wiring as soon as we have it done!

Comments, thoughts?
 
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Noice! I really like this mod. Will put it on my to-do list to get back to running my ARB fridge. Only different is I will go with the Sure Power isolator like I had in my Tacoma. Great job!
 
That kind of looks like my setup, but i used the Sure Power isolator. It sure is nice to have two batteries sometimes
 
So can you explain a little more the reason for the radiator cut out? Also what's wrapped around the "new" overflow tank?
 
So can you explain a little more the reason for the radiator cut out?

The 2 optimas will not fit in the stock location without modification. Most cut the radiator plastic.

You can see in my setup, the fender was bent/molded in order to avoid cutting the radiator.

DSC02686.JPG
 
The radiator cutout is just to make the two batteries fit in the space. As for the new Overflow bottle, I wrapped it in Rubber (old inner tube) to stop any potential friction or wear on it or parts around it, The bottle does not touch anything at the moment, but you never know what happens when everything settles into place while driving... Precautionary that's all.
 
Clean work to both. I'm looking to install a second yellow top in the rear cargo area. It would be great if you post up a wiring diagram. I've got electronics experience just never in the area of multiple battery setups. Thanks, Jon
 
There's a number of different ways to wire it, they mainly depend on how you want to separate (or join) the batteries.

I have an 140 amp battery isolator which is connected to the alternator and then splits the charge between the 2 batteries but ensures they don't drain each other.

The national luna kit has a nice manual which walks you through the different types of connections and will give you an idea how to get started:
http://www.nationalluna.com/Datasheets/Split-charge manual.pdf
 
For what it is worth, The Police Tahoe's with factory dual batteries connect both batteries to the starter. A lot of the Escalade owners (they have a secondary spot for a battery but no battery) who are wanting to install a second battery are buying the Tahoe's secondary battery harness and tying it directly to the starter for an OEM look.
 
wow yellow and red top that is a lot of mula

I hear that. Thats why i kept my stock battery and used a yellow top optima that would fit. I only went off the dimensions. When i did this i had just got a battery warrantied from Kragen so it was brand new, and free.

I didnt see a reason to run two full sized optimas. I will never have an on board fridge/freezer and the small optima I have has enough juice for a few winch pulls with the truck off, and can run my cb/ or lights all day or night with the truck off.
 
Clean work to both. I'm looking to install a second yellow top in the rear cargo area. It would be great if you post up a wiring diagram. I've got electronics experience just never in the area of multiple battery setups. Thanks, Jon

I will be writing an article about it on our Blog Life Remotely: Redefine Travel. Live and Work Anywhere. Become location independent or a digital nomad. | Life Remotely and be positing it by Friday next week, We have done the wiring and will have full schematics on the wires and wiring diagram for you and anyone else interested.
 
The Install article has been published!

Hello All

My Apologies for the long delay in the Article, but it is now written and published. It is a two part series, the second part will be published Later this week and will cover the wiring with detailed wiring diagrams and some great photos of the fuses and Cables.

Let us know if there is additional info you need!

Link to the Article is here How to Install a Dual Battery system in a 1997 Toyota 4runner
 
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wow this is the best write up i fund so far, question? can i use two difference brand of batteries ?


I don't think the cables know what brand battery they are connected to. Also a lot of the dual battery systems are set-up with one starting battery and one deep cycle and few are matched brands. I do like the fact that the OP used same brand but it is not a neccesity. Jmoney is using one factory battery and one Optima.
 

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