# Dual battery setup.



## Laszlo Almasi (Feb 11, 2006)

Ok, I just got my dual battery setup parts in and will be installing it soon but was wondering what battery manufacturer those of you that had dual batteries prefer.


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## REAPER (Nov 23, 2004)

Autozone Duralast. Thumbs Up


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## Pharoah72 (Feb 21, 2010)

Where did you get the Battery Cables? Are you using a Combiner / Isolator? I got everything in myself 'cept for the Cables.


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## Laszlo Almasi (Feb 11, 2006)

You can actually go to just about any car audio store and get some Monster Cable wire for what you will need.

I'm not going to be runnng an isolator just yet. My only need at the moment will be for the use of the plow and with mking my own cable ends, I can pretty much make quick disconnects so I can disconnect the extra battery when not in use.


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## hitachiman 200 (Jan 17, 2010)

Laszlo Almasi;1146066 said:


> You can actually go to just about any car audio store and get some Monster Cable wire for what you will need.
> 
> I'm not going to be runnng an isolator just yet. My only need at the moment will be for the use of the plow and with mking my own cable ends, I can pretty much make quick disconnects so I can disconnect the extra battery when not in use.


Isolators are used to separate your car/truck/boat engine system from your deepcycle lighting/accessory system,where you have dissimilar batteries and wish to charge from a single source(alternator).
A dual battery setup as in your plow truck should have 2 batteries of the same make,size and age so that they work as a combined unit and are balanced. Other wise if one is stronger than the other the weaker one will be constantly sucking juice from the stronger one. Think of 2 tanks of air, 1 has 50psi and a the new one has 100psi, when connected together they want to balance out to 75psi. Problem is that the old tank can only hold 50psi before it leaks out so the new tank keeps pushing into the old tank until it to only has 50psi and is now balanced. The same holds true for a battery rated at 650 and one at 850 if left together the 650 will draw down the 850 until the are balanced.
When they are being charged by the alternator because it pushes 14.5 volts it essentially is bigger than both and therefore charges them both.But when one of the batteries is larger than the other the alternator has to work harder therefore decreasing its life as well.
You are better to leave both batteries as a unit so that they last longer because each battery now shares the load and only works half as hard.


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## Laszlo Almasi (Feb 11, 2006)

That is correct but as I stated, I won't be running one at the current time. My batteries will be ok until I decide on which particular setup I intend to run. But in the meantime, I won't run into any problems.


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## Pushinsnow (Dec 18, 2007)

This is the setup I have in my street truck and plow truck. Both have 200 amp alternators, 200 amp isolators, and dual batteries. You should always use a isolator whenever running two or more batteries.


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## PabstBlueRibbon (May 11, 2010)

Farm and Fleet they have a no questions ask return policy so every 3 years new free batteries


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## justme- (Dec 28, 2004)

Hitachi man is correct- the point was, laszlo, unless you intend to run 2 different batteries in either type, size, or age, you do not need isolators.

Buy 2 of the same battery at the same time and all will be well. Personally I like Interstates- had great luck with them whereas I have had bad luck with most auto parts stores chain batteries and Sears. 7 years on the interstates in my Dodge, had 5 on the factory Mopars and changed them a little early to be safe. Just changed the Wife's factory Mopar battery from 01.

also for a plow rig you want a battery with higher reserve capacity as opposed to super high CCA- if one 700CCA battery got you running before the dual setup that's enough CCA for the new setup but longer reserve capacity means longer time the battery can supply current before running to low which can compensate for a lower output alt and help when you have a alt failure.


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## Laszlo Almasi (Feb 11, 2006)

justme-;1157369 said:


> Hitachi man is correct- the point was, laszlo, unless you intend to run 2 different batteries in either type, size, or age, you do not need isolators.
> 
> Buy 2 of the same battery at the same time and all will be well. Personally I like Interstates- had great luck with them whereas I have had bad luck with most auto parts stores chain batteries and Sears. 7 years on the interstates in my Dodge, had 5 on the factory Mopars and changed them a little early to be safe. Just changed the Wife's factory Mopar battery from 01.
> 
> also for a plow rig you want a battery with higher reserve capacity as opposed to super high CCA- if one 700CCA battery got you running before the dual setup that's enough CCA for the new setup but longer reserve capacity means longer time the battery can supply current before running to low which can compensate for a lower output alt and help when you have a alt failure.


That is correct. I've actually been looking at the possibility of running four 6v batteries in series/parallel rather than two 12v batteries is parallel only. The RC of 6v power cells is much higher and with the doubling of RC per set of 6v batteries I will have more than enough RC for my rig. The problem is however...those 6v batteries typically do not supply sufficient current for my starting needs.


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## 2COR517 (Oct 23, 2008)

Pushinsnow;1155836 said:


> You should always use a isolator whenever running two or more batteries.


Don't tell the big rig guys.........


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