# Dual batteries



## Henry0016 (Jun 6, 2005)

I'm wondering if anyone knows where I can get a dual battery kit for a 2002 Chevy 2500 HD 6.0? 
Any info would be great!:salute:


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## Yaz (Apr 13, 2005)

I think you'll have to get the try from the dealer. Cables can be too much.. Replace both batteries !!


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## Northland (Oct 1, 2006)

Let me know if you find out anything on this. I am interested in doing this as well.


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## SnoFarmer (Oct 15, 2004)

Yaz said:


> I think you'll have to get the try from the dealer. Cables can be too much.. Replace both batteries !!


A couple of cable ends. lol:waving:

Remember, you do NOT want to use a battery isolator for plowing.
Hook them together directly. + to+ & -- TO--.

What is in this "kit"?


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## Yaz (Apr 13, 2005)

I meant battery tray, not try. opps

Yes, plus to plus and negative to negative is the way to go. This doubles the amperage, but both batteries have to be exactly the same size and age to do it right.


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## Northland (Oct 1, 2006)

Yeah...I know all about parallel and series... I was just wondering more about mounting it. I didnt know if you could get a tray for it or not.


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## ipc (Oct 18, 2006)

It's easy to do. You can go to GM and get a new tray for about $45. Order a left side tray for a diesel . It bolts right in. When you wire your batts remember to also add the aux grounds from the extra batt. 1 to the engine, 1 to the body. This is very important as it will not charge properly otherwise. Some times you have to move a aux tool box first but I have done this to all my plow trucks.


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## Favatts (Dec 30, 2003)

When you get dual batteries from the factory are they hooked up positive to positive, negative to negative like you guys have suggested?
Favatts


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## calhoun (Oct 18, 2003)

Favatts said:


> When you get dual batteries from the factory are they hooked up positive to positive, negative to negative like you guys have suggested?
> Favatts


From the factory there are 2 dual battery options. One is as above pos to pos and neg to neg. This is how all diesls are hooked up and is the best system for plowing.
The other factory option uses an isolator on the second battery. This is good for trailer, inverter use where you don't want to drain the starting battery but want both to charge.
The rpo code for the dual battery isolator is 8BO and for the dual battery parrall hook up is TP2.


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## Snowman19 (Sep 30, 2006)

I have dual batteries in my 01 2500HD Are they already hooked together?


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## joe b (Oct 1, 2006)

Yes, 
If you wire in parallel ie. pos to pos/ neg to neg, and your batts are 600cca each you have one big 12volt battery with 1200cca. If you wired them in series pos to neg, truck ground to neg, truck pos to pos. you would have a 24 volt 600cca battery. so unless your truck says catapillar on the side. wire them parallel.


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## calhoun (Oct 18, 2003)

Snowman19 said:


> I have dual batteries in my 01 2500HD Are they already hooked together?


If you have 2 batterys they must be hooked together. If not you could not charge both off one alternator. It is just a question of how they are hooked together. See my above post, look in your glove box, and see what RPO code is listed. That will tell you how they are hooked up.


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## dutchman (Aug 20, 2005)

Snowman19 said:


> I have dual batteries in my 01 2500HD Are they already hooked together?


Hi I looked under the hood on my 2001 2500 HD I think there is no space can you tell me how you did it and do you have pictures.


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## DugHD (Nov 1, 2005)

dutchman said:


> Hi I looked under the hood on my 2001 2500 HD I think there is no space can you tell me how you did it and do you have pictures.


Dutchman- here is a pic of a 2001HD2500 with dual battery set up. You can see one in the front right and the back left. Hope this helps. doug


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## dutchman (Aug 20, 2005)

Thanks Doug that will help


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## Triple L (Nov 1, 2005)

When you put in your second battery did you have to remove the brace that was on there. On my 06 there is a brace which is supporting the fender there which is preventing me from putting a battery there.


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## DugHD (Nov 1, 2005)

Hi, my dual batteries came that way new. Maybe the battery tray helps support the fender a little? doug


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## markq (Sep 22, 2005)

Just remove the brace. I did this on my '04 and the tray bolted right in. It was a liitle difficult figuring out a way to secure the battery so that it didnt move but still cleared the hood when closed, but it can be done.

I agree with everyone else on hooking up + to + and - to -, but it might not be bad to use an isolator when the truck is off....

I have mine setup with a 200A relay that connects the batteries when the key is turned. This makes sure that I get the extra amps, and also makes sure that the batteries both stay charged, but if the main battery runs down, I can still start with the second battery. Also I run my lights sometimes with the truck off - since they are connected to the second battery if I should happen to run the battery down, I will still have the main to start the truck with.

Just another option - oh, and its a REALLY good idea to get identical batteries for this.


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## GetMore (Mar 19, 2005)

I picked up a battery isolator/combiner from Hellroaring for my dual battery setup. It has a switch so you can combine the two batteries, so both power the plow, or so if the main battery dies you can still start the truck. In normal operation it isolates the batteries, so you can use different rating/age batteries and not worry about them discharging each other.


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## SnoFarmer (Oct 15, 2004)

GetMore said:


> I picked up a battery isolator/combiner from Hellroaring for my dual battery setup. It has a switch so you can combine the two batteries, so both power the plow, or so if the main battery dies you can still start the truck. In normal operation it isolates the batteries, so you can use different rating/age batteries and not worry about them discharging each other.


If you flip the switch and "combine" them you need to have the same "rating/age batteries"
The way your describing your set up will be only as good as the weakest/smallest battery is when "combined". 
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markq

I agree with everyone else on hooking up + to + and - to -, but it might not be bad to use an isolator when the truck is off....

I have mine setup with a 200A relay that connects the batteries when the key is turned. This makes sure that I get the extra amps, and also makes sure that the batteries both stay charged, but if the main battery runs down, I can still start with the second battery. Also I run my lights sometimes with the truck off - since they are connected to the second battery if I should happen to run the battery down, I will still have the main to start the truck with".
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That is true. But you have not supplied more power for the plow, an isolator defeats the purpose of the second battery.

You want the plow to have readily available amps, lots of them. The only way to do this is to have the batts working together to run the plow.

The two batts will have enough reserve to run your lights for a while with the truck off too.
But why turn the truck off, let it idle, it is easer on it than restarting it all of the time.


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## PLOWMAN45 (Jul 2, 2003)

is there a place where you can get the stuff with out having to pay expensive gm parts


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## Henry0016 (Jun 6, 2005)

do i go from the + terminal on the battery to the + on the other battery.and in what order. were should i ground the -. 

Any help would be great


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## SnoFarmer (Oct 15, 2004)

Henry0016 said:


> do i go from the + terminal on the battery to the + on the other battery.and in what order. were should i ground the -.
> 
> Any help would be great


Run the neg back to the other batt too. 
Then run grounding straps to the body, frame and engine.


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## Henry0016 (Jun 6, 2005)

Stupid question what is the ground strap


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## SnoFarmer (Oct 15, 2004)

lol... not stupid at all...

A piece of braided wire that is flat like a strap with no covering on it.

There still used on some trucks to ground the box to cab.(body ground)
Any heavy wire will work as a grounding wire.(strap)


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## Henry0016 (Jun 6, 2005)

Connect that to the neg terminal then to body do this on both batts


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## SnoFarmer (Oct 15, 2004)

I know it sounds redundant but yes. 
The stock batt probably is grounded to the fender and engine already.
You want to ground the (new) second batt in the same fashion,and while were at it where is the ground wire for the plow going?

Some say to just ground it any where, others say the batt, I like to ground it at the same place the Alt is grounded to.


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## PLOWMAN45 (Jul 2, 2003)

someone told me to use 1 gauge wire


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## SnoFarmer (Oct 15, 2004)

PLOWMAN45 said:


> someone told me to use 1 gauge wire


That will work,, I Used 4ga, the same size most jumper cables are.


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## Henry0016 (Jun 6, 2005)

where should the soloed go. should it hook into the second battery or does it not matter. Right now it gets its power from the red boxes were the factory battery goes.Is this OK or should i move it.


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## SnoFarmer (Oct 15, 2004)

You can leave the solenoid where it is.:waving:


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## Triple L (Nov 1, 2005)

just installed 2- 850 CCA batterys this weeked, two days latter and about $350.00 and its done. I used 2 gage wire which is nice. Alot bigger than 4 guage. My plow dealer was trying to say 4 gauge would be good but I'm glad i went with the 2 guage. Just took that brace on the fender off and placed the battery right on the fender there than secured it by drilling a hole though that plastic crap and tightened it down. Havent put the plow on yet but she sure turns over alot stronger now, cant wait to see how it works with the plow, now I have 1700 CCA instead of the stock 600 CCA. What a differance. I'll post some pics this coming weekend.


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## Rick Loncosky (Dec 14, 2002)

My 86 K30 w/ 6.2L diesel has dual batteries. They are both on the passenger side. They are hooked in series (pos to neg) does this mean I have a 24 volt starter? What about the lights and other electrical stuff? It also has dual alternators. I haven't seen this before, does anybody know if the alternators charge individually each battery or both together.........Would anyone have a wiring diagram for this system? Thanks for any info you can provide!!!!


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## markq (Sep 22, 2005)

QUOTE - 

markq 

I agree with everyone else on hooking up + to + and - to -, but it might not be bad to use an isolator when the truck is off....

I have mine setup with a 200A relay that connects the batteries when the key is turned. This makes sure that I get the extra amps, and also makes sure that the batteries both stay charged, but if the main battery runs down, I can still start with the second battery. Also I run my lights sometimes with the truck off - since they are connected to the second battery if I should happen to run the battery down, I will still have the main to start the truck with".
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

That is true. But you have not supplied more power for the plow, an isolator defeats the purpose of the second battery.

You want the plow to have readily available amps, lots of them. The only way to do this is to have the batts working together to run the plow.

The two batts will have enough reserve to run your lights for a while with the truck off too.
But why turn the truck off, let it idle, it is easer on it than restarting it all of the time.



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SnoFarmer............I dont understand how the plow wont have all the amperage from both batteries available when I'm plowing. I dont use the plow without the engine on, and anytime the engine is on the batteries are connected. They are only isolated when key is off.

That was the whole point of having the relay put in there.... to connect the batts when the engine is running, but not when its turned off.

Am I missing something???

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## SnoFarmer (Oct 15, 2004)

markq said:


> QUOTE -
> 
> markq
> 
> ...


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No, I was missing something. lol

Your set up is _not_ the typical one you see when people use an isolator.

One Q. How big are the wires your are using with the relay to connect the batts?


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## Triple L (Nov 1, 2005)

Do any of you guys got a high output alternator, I'm not sure if myn is going to be up to the task. It's always running at 16 or so, Way higher than 14. How long should a stock alternator last under plowing conditions?


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## markq (Sep 22, 2005)

SnoFarmer said:


> ----------------------------------------------------------------------------------------------------------------------------------
> No, I was missing something. lol
> 
> Your set up is _not_ the typical one you see when people use an isolator.
> ...


I know thy're at least 4AWG - maybe even 2AWG


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## carl b (Dec 28, 2006)

WOW the search button what a great thing !!!! i hooked up my two batt. a few years ago and went + to +..but not - to -should i change this or will i have to buy new batt's?? the only reason i did this is i have to replaces my other trucks batt..and also looking for a tray.
 thank you for any info...


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## mcwlandscaping (Sep 8, 2005)

went pos. to pos. neg to neg with mine, LOVE the dual battery setup! before, the second battery was on an isolator thing and it didn't charge right and didn't help the truck at all! Disconnected all that crap, two new batteries and a couple of battery cables later, i'm a very happy camper! Noticed the difference the first time i started up the truck.

btw, cables at autozone cables are great!! was $16 for BOTH of the ones i needed. NAPA was trying to charge me $90 for both :realmad: :realmad:


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## boothdir (Jan 24, 2014)

I know this is an old thread but I'm guessing some of the folks that posted here can answer my question. I have a 2002 Silverado 2500HD with the factory dual battery set up where the second battery is isolated. If I want to switch it over so they are in parallel can I just disconnect the positive line from the second battery and run a cable from positive to positive on the two batteries? I'm assuming that the factory wiring for the isolated battery already has the negative terminals connected to one another and the chassis or is that incorrect?


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