My Dual Battery Setup

[tech_dog]

I think this is a bit different from the other dual battery setups I’ve seen, so I thought I’d post it up for reference. Sorry about the lame pictures. I think I got some water in my camera. I’ll replace them when I get a new camera.

Step 1 – Clear some space

I used the Slee kit to move the windshield reservoir.

I’ve got a 94, which means I had a resonator/silencer in the area where the second battery needs to go. I think most people just remove it and replace it with a straight hose, but I didn’t want to change the sound of the truck.

I did this (purple dot):



I made the modified resonator out of two resonators. I cut off the top opening of the old one, cut and sanded to shape, used four screws to get a nice solid connection, and then used JB weld to make it airtight. Then I bent a bit of metal, and cut and shaped some hose. It wasn’t much extra effort and I didn’t have pull anything off my truck.

[tech_dog]

Step 2 - Run the main wire

I wanted to fuse my work, so I used an ANL fuse block. These are bigger than I wanted, and I’m still looking for something that will fit right behind the battery box. The compromise here is that I’ve got something sitting on top of one of my OEM fuse boxes, but then again, in 11 years I’ve never blown a fuse. Once I find a phisically smaller high amp fuse block, I won’t have to make this compromise.




I used marine grade 0 gauge, wrapped in combing, crimp on terminals, and 3 wall heat shrink. I also ran a negative connection from the second battery to the same point on the block where the primary battery is grounded. I used the OEM raceway in front of the radiator. I doubled up on the combing through the raceway, and tripled it at the entry and exit points. I’m really glad I bought the crimper, as it let me run all the wires without any excess at all.

[tech_dog]

Step 3 - Do the switches

The core of the system is the Blue Sea 9112 solenoid. It’s gasoline vapor safe, hermetically sealed, and can handle 400 amps for 10 seconds. Inrush rating is 2000 amps. This switch automatically combines the batteries when the alternator is charging. I put in an interior switch that can also set it to manually connect or disconnect.



I had a occasional problem with it not disconnecting when I turn off the vehicle and am in the auto mode. My batteries are new and well charged, and are probably just over the threshold required to shut it off. I added a silicon diode in parallell with a 50 ohm resister to the solenoid ground wire circuit, which will drop the perceived line voltage on the control circuit by about .7 when the solenoid is closed, but causes almost no drop when the solenoid is open. This seems to have solved the problem and the controller is behaving perfectly.

http://www.bluesea.com/product.asp?Product_Id=22756&d_Id=7458&l1=7458&l2= 7458

I also used a blue sea 6007 miniature battery switch for the winch. It allows the winch to run off either battery or both, and it can also give a physical connection to both batteries for a last ditch two battery start attempt if the batteries are too dead to control the solenoid. I used it because it’s small.

http://www.bluesea.com/product.asp?Product_Id=174050&d_Id=7458&l1=7458&l2=

I made a C bracket and mounted the switch on top with the solenoid directly below the switch. It seems tidy and compact. In fact you can barely even see the solenoid down in the hole.




Instead of rigging a stock button to control the solenoid, I decided to make it look like what it is. I can manually combine the batteries, disconnect them, or automatically combine them based on alternator output. I tucked the switch back a bit so that you don’t see it unless you look for it, but it’s still easy to reach.

http://www.bluesea.com/product.asp?Product_Id=173904&d_Id=7458&l1=7458&l2 =7458

The light turns green whenever the solenoid is closed.

[tech_dog]

Step 4 - Shove in an expensive battery

I used the Dual Pro LS 2700. It puts out 800 CCA, 1100 MCA, and has a 175 minute standard reserve capacity. It’s an AGM dual purpose battery, and is a group 27 so it fits right. It’s a bit shorter than the stock batteries, and you can get the cool battery terminal blocks that serve as a distribution bus.



http://www.dualpro.com/new/ls2700.html

That’s pretty much it.

Capabilities include:

1) Automatic control from within the vehicle, including combining batteries, isolating batteries, or leaving in automatic which joins then while the alternator is charging.

2) Starting the vehicle off of one battery or both, controlled from within the vehicle

3) Running the winch off either battrey or both.

4) Disabling the winch power

5) Mechanically join both batteries for last ditch start atttemp, even if the batteries are too low to power the solenoid.

6) Fuses on everything

7) Indicator light in vehicle tells you what the solenoid is doing

8) "Bolt-on" electrical connections. I didn't alter any OEM wiring, and hooked in at single fused connection. I could pull this all out and put it back the way it is was any time.


Here’s the schematic:



I'm using the 35 amp fuse to make sure I protect the stock system. I will switch to the 400 amp fuse before any trips where I may need the winch or an emergency start from the second battery.

[Romer]

Nice setup. I will add that to those I am considering. I just moved the washer bottle and added the 2nd tray. Great write-up.

Please got to the FAQ and post a link to to your write-up in this thread:

http://forum.ih8mud.com/showthread.php?t=81537

[Brentbba]

Nice! You confirmed what I thought had to be necessary - loose the resonator.

For anyone that has just gone the straight hose route with a '94, how much different does the truck sound?

Also, does the resonator have anything to do with the smog police here in Kalifornia?

[TCH2FLY]

WOW Nice Tech Dog. I considered doing exactly the same thing to my resonator but felt it would be a little crowded. I like your results.

Originally Posted by Brentbba

For anyone that has just gone the straight hose route with a '94, how much different does the truck sound?

My result, with a snorkle installed, is very noticable rumble on cold start in the morning inside my garage but I would not consider it annoying or bothersome.

[Brentbba]

How about a running temps, idle etc?

[tech_dog]

Originally Posted by TCH2FLY

WOW Nice Tech Dog. I considered doing exactly the same thing to my resonator but felt it would be a little crowded. I like your results.

It doesn't look crowded at all. It came out looking very much like it could have been OEM. I showed the work to a friend of mine, and at first he didn't believe that it was just a hack.

I was also a bit concerned about exposure to a heat source on that side of the engine, but after a lot of feeling around before and after the job, I don't think that's a problem either.

[tech_dog]

Originally Posted by Brentbba

How about a running temps, idle etc?

The resonator/silencer is just an empty box. I can't see how it would do anything beyond reducing the gurgling sound that people sometimes get without it.

[TCH2FLY]

Originally Posted by Brentbba

How about a running temps, idle etc?

For the most part PAIR operation occurs when the engine is cold and is at lower RPMs. It's operatation with the engine warm it is so brief and occurs under such limited situations that you will probably never hear or notice it.

I think that in my case the snorkle amplifies the sound (especially in the garage)...I would be interested to hear from someone without a snorkle.

[Brentbba]

Originally Posted by tech_dog

The resonator/silencer is just an empty box. I can't see how it would do anything beyond reducing the gurgling sound that people sometimes get without it.

LOL! Thanks!

[tech_dog]

Originally Posted by TCH2FLY

I think that in my case the snorkle amplifies the sound (especially in the garage)...I would be interested to hear from someone without a snorkle.

While researching this, I found a thread from someone who removed the resonator and noticed a small amount of gurgling. Later in the thread he added a snorkel and said that it made the difference much more pronounced.

[cruiserdan]

Originally Posted by Brentbba

Nice! You confirmed what I thought had to be necessary - loose the resonator.

For anyone that has just gone the straight hose route with a '94, how much different does the truck sound?

Also, does the resonator have anything to do with the smog police here in Kalifornia?

There is a not unplesant "burble" when the engine is cold idling. This lasts for a couple minutes. Then it kicks in on decelleration when the throttle plate is closed, sounding sort of like a minature Jake Brake on a diesel. I kinda like it actually. It is nore noticable with a snork.

It has no "emissions function" and is strictly a muffler.

[tech_dog]

One late addition I'll add to this is that I leave the automatic solenoid in the "off" position more than I expected. When using a lot of charge off battery2 I'll throw it back into automatic during the use, and for a few days following the use, but then I'll manually shut it down until the next time I drain off the charge.

This avoids obvious overcharging.

So far so good. Everything has worked perfectly for about a year now.

T.

[Brentbba]

Originally Posted by cruiserdan

There is a not unplesant "burble" when the engine is cold idling. This lasts for a couple minutes. Then it kicks in on decelleration when the throttle plate is closed, sounding sort of like a minature Jake Brake on a diesel. I kinda like it actually. It is nore noticable with a snork.

It has no "emissions function" and is strictly a muffler.

Now that I've had the snorkel on for awhile - this is a perfect description of the sound. I have to agree that it is not unpleasant at all. I kind of like it too!

[dfmorse]

Nice work.

Removing the resonator on my '94 made is sound like a super charger; oh, wait , I do...

[Brentbba]

Originally Posted by dfmorse

Nice work.

Removing the resonator on my '94 made is sound like a super charger; oh, wait , I do...

[CoveredInRedMud]

Originally Posted by tech_dog

One late addition I'll add to this is that I leave the automatic solenoid in the "off" position more than I expected. When using a lot of charge off battery2 I'll throw it back into automatic during the use, and for a few days following the use, but then I'll manually shut it down until the next time I drain off the charge.

This avoids obvious overcharging.

Do you use a voltmeter to determine when your 2nd battery charge has been adequate, and what volts do you look for usually?

I think I'm going to put a switch on the voltage sense wire to my Engel solenoid and do the same -makes sense not to overcharge when not using much.

[tech_dog]

For the most part, I'm currently "timing" the charges. I'm still looking for a compact two-battery voltmeter to permanantly install.

Occasionally, usually before and after a camping trip, I use a portable voltmeter and aim for about 12.8-12.9 volts for full charge.

[CoveredInRedMud]

I hear ya, I've been looking for that kind of digital voltmeter setup for a long time, something that looks nice but not obtrusive like the big green LCD displays you can get on eBay. I'd even settle for a single small display with a toggle switch to go between the main and house, although a stack with both would be best. Let us know if you ever find one...

[aktundra]

Instead of rigging a stock button to control the solenoid, I decided to make it look like what it is. I can manually combine the batteries, disconnect them, or automatically combine them based on alternator output. I tucked the switch back a bit so that you don’t see it unless you look for it, but it’s still easy to reach.

[aktundra]

Sorry for the misfire with that previous post. I was trying to figure out how to include my first quote in a reply ! A complete whif!!?!?!?

Here is what I really wanted to send:

Originally Posted by tech_dog

Step 3 - Do the switches

Instead of rigging a stock button to control the solenoid, I decided to make it look like what it is. I can manually combine the batteries, disconnect them, or automatically combine them based on alternator output. I tucked the switch back a bit so that you don’t see it unless you look for it, but it’s still easy to reach.

I am leaning pretty heavily on this thread to design my dual bat installation. However I am trying to get the interior look & feel as close to OEM as possible. tech_dog referrs to " . . .rigging a stock button . . . "

Can anybody post p/n & pics of interior switching controls for a dual battery system with something of an OEM feel?