Dual Battery Install

Joined
Jul 20, 2010
Messages
84
Location
Colorado Springs, CO
I thought everyone might want to see my dual battery install.

Here are the big parts I used, what they cost and where I got them:
1. 4+ battery tray, $125 from man-a-fre
2. Painless waterproof dual battery control system, $180 from Spider Performance Accessories (most places are about $225ish).
3. Blue top Optima battery, $160 from COSTCO.
4. All new battery cables from FOURRUNNER here on IH8MUD, his standard kit is $130 plus I ordered 3 extra cables to set up the dual system. I'll defer to him on pricing for a dual battery kit.

Here are some learning points:
1. The 4+ battery tray is nice. It is pre drilled for the Painless solenoid and has a spot to relocate the radiator overflow. I mounted the tray low as there were 2 holes in the front wall by the headlights that I could use and not have to drill. This meant that I couldn't use the spot for the radiator overflow bracket. I simply bought a big hose clamp from Home Depot and slid it further around the driver's side and used the big holes in the fender to route the clamp. I also needed about 4 feet of the little hose to go from the radiator to the overflow.
2. The Painless system has you tap into an ignition wire that is hot when the key is in run or start only. The manual said the wire was black and blue, but in reality it was green and white. Once I got into the steering column, the spots are numbered in the metal on the back of the ignition. THose numbers corresponded to the numbers in the manual. I found that the switch fit nicely between the interior light rheostat and the electric mirror adjustment and by removing the little door over the fuse panel you have easy access to this spot. Painless says to route the primary battery positive from the battery to the solenoid and then a second cable from the solenoid to the starter. I kept FOURRUNNERs standard set-up and ran a cable from the battery to the starter and the soleniod to the primary battery. This way works perfect too.
3. I went with the blue top Optima because they say it is for boats and RVs that sit for a long time, COSTCO seemed pretty cheap. When my primary dies, I think I will use a yellow top there. Lots of debate over batteries, my 2 cents.
4. FOURRUNNERs battery cables are awesome. As everyone says in the link below, the pics don't do them justice. These cables, along with SLCFJ62s headlight wiring harness (https://forum.ih8mud.com/merchandise-storefront/354712-headlight-wire-harness-fj60-fj62.html) and my voltmeter is now solid as a rock. I installed his standard kit as advertised, no issues. I ordered three extra cables, a 4 foot positive to go from the solenoid to the primary battery. A 1 foot positive to go from the second battery to the solenoid and a 2 foot ground to from the second battery to the hook on top of the engine. Here is a link to his cables:
https://forum.ih8mud.com/merchandise-storefront/343236-fj60-fj62-heavy-duty-battery-cable-sets.html

Overall, I am happy with the install. The scariest part of the whole thing was cutting the ignition wire. In the end she fired right up, and now I can jump myself when I'm an idiot and leave my lights on at the airport. Not that that's what prompted me to take this project on....

Here are some pics:
CIMG1534.jpg
CIMG1535.jpg
CIMG1537.jpg
 
Joined
Jan 21, 2010
Messages
246
Location
VT
Nice job and nice write up.

Two questions for you:
How did you run the cables from one battery to the solenoid?
What exactly is above (or apart of) the switch? Indicator lights, did that come with the painless set?


Thanks,

S
 
Joined
Jul 20, 2010
Messages
84
Location
Colorado Springs, CO
For the solenoid, the second battery positive goes to one side of the solenoid and a cable from the other side of the solenoid goes to the main battery. So both batteries are hooked to separate sides of the solenoid and that is how you either isolate them or use them together based on the switch position in the dash.

The switch has three positions. In the center, neither of the lights is lit and the second battery is completely isolated (no power to Cruiser, no charge to battery) this lets you drain your main battery (say winching yourself out of a mud hole) and then have the ability to engage the solenoid and jump yourself with the second battery. With the switch to the right, the green light is lit and the solenoid is energized when the ignition is in 'run' or 'start'. This lets you use both batteries to start the Cruiser (say it's really cold out) and charge the second battery. With the switch to the left, the red light is lit and the solenoid is engaged and powered by the second battery regardless of ignition position, the key doesn't have to be in the ignition (this position is how you would engage the solenoid and jump start yourself after killing your battery with the winch).
 
Joined
Jun 14, 2009
Messages
40
Location
Bakersfield, CA
Very nice write-up. I've been wanting to add another battery to my 62 and I think this is the way I'm gonna go. I already have a Yellow Top in it and I have a spare Red Top sitting in my garage; patiently waiting. THX!
 
Joined
Dec 11, 2008
Messages
2,015
Location
Whidbey Island, WA
It sounds like this system will combine the batteries if you chose that option. This means you need to run the same type and preferably age batteries. Do NOT mix deep cyle and start batteries in such a system, for example a yellow top or blue top with a red top optima. Also don't mix AGM's with wet cells. Jumpstarting one with the other is OK but your alternator wasn't designed to charge two types of batteries at the same time.

If you want to run two types, a deep cycle and a start battery you need an automatic charge relay or an isolator that keeps them seperate. It doesn't sound like this system has one. Or does it? You should never combine, (meaning leave them connected together for charging) a deep cycle with a start battery for an extended period. To learn what makes them different you may want to read this.http://thewagonway.com/?p=2040 You will also find a write up about what kills a battery.

I love my Optima's but don't expect really long life from them. My last pair lasted only about 4 years and you might be surprised the warranty is only 3 years... Even so I bought another pair of Blue tops.

Tony
 
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Joined
Jun 14, 2009
Messages
40
Location
Bakersfield, CA
It sounds like this system will combine the batteries if you chose that option. This means you need to run the same type and preferably age batteries. Do NOT mix deep cyle and start batteries in such a system, for example a yellow top or blue top with a red top optima. Also don't mix AGM's with wet cells. Jumpstarting one with the other is OK but your alternator wasn't designed to charge two types of batteries at the same time.

If you want to run two types, a deep cycle and a start battery you need an automatic charge relay or an isolator that keeps them seperate. It doesn't sound like this system has one. Or does it? You should never combine, (meaning leave them connected together for charging) a deep cycle with a start battery for an extended period. To learn what makes them different you may want to read this.The Wagon Way You will also find a write up about what kills a battery.

I love my Optima's but don't expect really long life from them. My last pair lasted only about 4 years and you might be surprised the warranty is only 3 years... Even so I bought another pair of Blue tops.

Tony

Good to know. Fortunately, I got the Red Top I was hoping to use for free. Looks like I have to start saving for a new one. Thanks for the info!
 
Joined
Jun 21, 2009
Messages
906
Location
San Marcos, CA
It sounds like this system will combine the batteries if you chose that option. This means you need to run the same type and preferably age batteries. Do NOT mix deep cyle and start batteries in such a system, for example a yellow top or blue top with a red top optima. Also don't mix AGM's with wet cells. Jumpstarting one with the other is OK but your alternator wasn't designed to charge two types of batteries at the same time.

If you want to run two types, a deep cycle and a start battery you need an automatic charge relay or an isolator that keeps them seperate. It doesn't sound like this system has one. Or does it? You should never combine, (meaning leave them connected together for charging) a deep cycle with a start battery for an extended period. To learn what makes them different you may want to read this.The Wagon Way You will also find a write up about what kills a battery.

I love my Optima's but don't expect really long life from them. My last pair lasted only about 4 years and you might be surprised the warranty is only 3 years... Even so I bought another pair of Blue tops.

Tony
The webpage you cite provides a simple explanation of the different types of common automotive batteries, but it doesn't explain what you claim is the big no-no...charging two different types of batteries. Please expand on your knowledge of this subject as I'm interested in the reasoning/theory behind it. Thanks.
 
Joined
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loveland, Ohio, USA
The webpage you cite provides a simple explanation of the different types of common automotive batteries, but it doesn't explain what you claim is the big no-no...charging two different types of batteries. Please expand on your knowledge of this subject as I'm interested in the reasoning/theory behind it. Thanks.

Don't quote me on this, but i think one of the main reasons for an isolator is to keep one battery from draining the other...

good looking set up....

:cheers:
 
Joined
Dec 11, 2008
Messages
2,015
Location
Whidbey Island, WA
The webpage you cite provides a simple explanation of the different types of common automotive batteries, but it doesn't explain what you claim is the big no-no...charging two different types of batteries. Please expand on your knowledge of this subject as I'm interested in the reasoning/theory behind it. Thanks.

This is where you get to know more about batteries than you want to know. If you noticed within that write up there is a link called www.batteryfaq.org If you go to section 7.1.9 It covers Dual and Multi battery systems. It also gives specific hazards of mixing deep cycle and start batteries. Rather than misquote him or cause further confusion please read it directly. This guy knows far more about batteries than I ever wanted to know.

Thats why I included the link in the write up. This is where I learned it's not a good idea to mix the two, if anyone knows differently please let me know as I always want to know more about the system I have in my rig. And there are tons of people out there who are far more knowledgable about battery systems than I, so research as much as you can.

As for more down to earth reasons, its primarily not a good idea because you will more than likely shorten the life of one of the batteries. At least according to the electricians I work with at the boatyard (if you ever want to see electrical nightmares take a look at the power system of a yacht). And at the cost of Optimas or other AGM's, shortened battery life is not something I want to do.

Tony
 
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Joined
Jun 21, 2009
Messages
906
Location
San Marcos, CA
Amazon.com: Managing 12 Volts: How to Upgrade, Operate, and Troubleshoot 12 Volt Electrical Systems: Harold Barre: Books

This is a really good book, it will tell you all you need to know.
I got mine from the library. happy reading:grinpimp:.
RAMZ

Thanks for the book link, Randy. I'm sure it's a worthwhile read and will look for a copy when able. :cheers:

Don't quote me on this, but i think one of the main reasons for an isolator is to keep one battery from draining the other...

good looking set up....

:cheers:

You're right, but there are two isolation concepts in the discussion. The isolation relay that allows the batteries to have a direct connection to each other with nothing but the current carrying capacity of the relay/cable to limit the flow of current in the system. The isolator has components that limit the flow of current between the batteries while still allowing them to charge from the same source. My question was referring to why the hubbub about the isolator when an isolation relay is generally thought of as a suitable, and simpler, selectable connection method that has less "stuff" that can go wrong with it.

Thanks for the input, though, I appreciate it. :cheers:

This is where you get to know more about batteries than you want to know. If you noticed within that write up there is a link called www.batteryfaq.org If you go to section 7.1.9 It covers Dual and Multi battery systems. It also gives specific hazards of mixing deep cycle and start batteries. Rather than misquote him or cause further confusion please read it directly. This guy knows far more about batteries than I ever wanted to know.

Thats why I included the link in the write up. This is where I learned it's not a good idea to mix the two, if anyone knows differently please let me know as I always want to know more about the system I have in my rig. And there are tons of people out there who are far more knowledgable about battery systems than I, so research as much as you can.

As for more down to earth reasons, its primarily not a good idea because you will more than likely shorten the life of one of the batteries. At least according to the electricians I work with at the boatyard (if you ever want to see electrical nightmares take a look at the power system of a yacht). And at the cost of Optimas or other AGM's, shortened battery life is not something I want to do.

Tony

Thanks for the link, Tony. I run a Yellow top and Red top through a simple 200A relay. I don't know if I buy the "overcharging" of the starting battery theory, but
it could have merit (in my truly humble opinion). I hadn't thought about the idea of high current as the batteries try to equalize upon connection. I'd say that anyone trying to jump start a severely discharged battery might need to consider this regardless of battery types in use.

I'm not going to run out and change my system yet, but I'll definitely do some more looking into the vulnerabilities of my system before I'm comfortable with it as it sits.

One last thing...be careful when listening to those marine sparktricians...we say a lot of things. :lol: :cheers:

(I'm admittedly a DC idiot as I spent all my time working on BIG AC generation and distribution equipment)
 
Joined
Jun 5, 2014
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I've been running two optimas in a parrallel configuration for a couple of years now without any problems. One deep cycle and one start battery. I've worked on diesels for years,and they all run duals just for starting amperage. The problem with this setup is you will drain both batterys at once, but it is a much simpler system.
 

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