# Need to run a second battery?



## ks_grasscutter

I am new to plowing with a truck, previously have just plowed with an ATV. I will be running an 8' straight blade, either Boss or Western. Do I need to add a second battery or upgrade my alternator in order to run the plow? Will be on a NBS 2000 Chevy 3/4 ton with the 6.0 engine.

Just ordered a set of Timbrens to keep the suspension from sagging. Also just had a new set of Hankook ATZs put on it. Anything else I need to watch for or upgrade?


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## Antlerart06

Yes and no I run one battery in my gas trucks 
Yes and No on a alternator All depends on the plow you buy what amps it draws IF plowing for 12 hrs straight might be better get a high amp alternator but if you plowing for a few hours no need for it


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## dieselss

Either extra batt or alt would be a good idea


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## JCByrd24

Try it out first and see how your lights and voltmeter react to the plow. Make sure you have good clean wiring connections and look into upgrading truck cables from alternator to battery regardless. 

Some newer Chevy's have computer controlled charging that does not react quickly enough to the plow amp draw and this causes the voltage to drop/lights to dim and in my case an ABS system message in the message center. In my case I upgraded to a single Diehard Platinum (Odyssey) AGM battery and this solved the problem of the voltage dropping low enough to trigger the ABS message. The next step would be dual batteries.

The plow is very intermittent duty and it alone will likely not require a larger alternator. If you have lights/spreader/other electrical loads that are continuous and add up to a lot of draw then you need an alternator, a battery alone will not help much here.

Think of it like this, the alternator is like the air compressor, the battery is like the air tank.


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## Moose's Mowing

I did both on my 04 2500. Prob didn't need to, but glad I did. I added a second battery on the pass side. Real easy to do. I put a 200-ish amp alternator on last week, haven't plowed with it yet though. Between my ipod being charged, cell phone charging, stereo going, heater fan on high, lights, the whirlybird lights and the plow, I was using a lot of juice and started to notice it after about 45 mins of plowing. Esp between driveways that are close together because I wasn't driving real far or running higher rpm's between drives to get a little extra charge to the single battery. I'd recommend doing at least an extra battery or a larger alt. It's there if you need it, and it won't hurt anything if you don't.


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## Antlerart06

MJ Services;1669337 said:


> I did both on my 04 2500. Prob didn't need to, but glad I did. I added a second battery on the pass side. Real easy to do. I put a 200-ish amp alternator on last week, haven't plowed with it yet though. Between my ipod being charged, cell phone charging, stereo going, heater fan on high, lights, the whirlybird lights and the plow, I was using a lot of juice and started to notice it after about 45 mins of plowing. Esp between driveways that are close together because I wasn't driving real far or running higher rpm's between drives to get a little extra charge to the single battery. I'd recommend doing at least an extra battery or a larger alt. It's there if you need it, and it won't hurt anything if you don't.


Only hurt there is when you have to replace battery's If one goes bad you really should replace both My power stoke need one battery but best replace both that was $350 for both


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## Dogplow Dodge

I plowed for 12 hours a few years back. With one battery, I had no noticeable issues. I did, however, put the largest / greatest CCA battery that I could fit in the truck. A NEW or reliable battery and alternator, to me, is more important than quantity of batteries used.

My box truck has dual batteries. It's designed so that when the user stops to load or unload, they can shut the truck off, get out, unload / load their cargo with the lights / flashers on, and have negligible effect on the battery capacity.

Not saying having a second battery isn't a good thing, as if I put a large electric salt spreader on truck, I would definitely consider installing a second battery.


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## Moose's Mowing

Antlerart06;1669374 said:


> Only hurt there is when you have to replace battery's If one goes bad you really should replace both My power stoke need one battery but best replace both that was $350 for both


very true. I added a battery to my camper and didn't replace both at the same time. I noticed a difference in run time. I'm lucky though, I live about 25 mins from Deka where they make batteries. They sell seconds/blemished batteries for dirt cheap. I got two new batteries for my truck when I added the second one. I paid around 100 bucks or so for both batteries including 2ga cables. I run these seconds in all my crap. My camper has two, jon boat has 3, truck has 2, tractor/mowers, etc etc. I've only ever gotten one dud battery.


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## cl733

2 batteries will run you a long time, small body high amp alternators aren't the best either,we run with 5 trucks running blizzard PP blades, the one truck with a single battery is constantly a problem,at coffee you leave that truck running,i use 2 group 65, batteries and plow back to back lots where im always swinging blades and have never seen a battery drain with a stock alternator


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## ks_grasscutter

Ended up running the stock battery and alternator on the first storm we had. Didn't have any problems, other than the radio stopping when I angled the blade. I was also running a LED strobe setup that plugs into the cigarette lighter. Probably will run without that next time as it wasn't as bright as I had hoped, so that may help some too.


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## absolute

It all depends on how many amps your pulling from your charging system, what your system can handle, and are you going to add anything latter. adding just a battery or just a alt may not fix your problem. For example if you add a battery you also need a battery isolator so you can properly charge both batteries. If your amp draw is 250 amps with running your heat, head lights, any emergency lights, plow, salt spreader, radio, ect. and your stock alt only puts out 160 amps your going to be putting a lot of alt on that truck. It wont matter how many batteries you have. Best place to start is how many amps are requierd to run what you want, can your alt handle it, and will adding a battery help for that surge when using your plow, sprader, or what ever.


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## dieselss

What's the point of running dual batts and then putting and isolator in the mix. Your still back to square one with only one batt doing all the work.


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## Monroe74

The point is the plow will use the one battery while the truck would use the other battery. And since each of those batteries will discharge at different rates the alternator won't need to charge both at the same time.


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## CleanCutL&S

Go with an AGM, like optima but many others on the market now.


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## absolute

dieselss;1701690 said:


> What's the point of running dual batts and then putting and isolator in the mix. Your still back to square one with only one batt doing all the work.


With out the isolator the 2nd battery will never charge. You will have the power of both battery's with that relay in place.


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## cl733

thats why you tag team up two in the first place, you have to sense a voltage drop to start a charge, cant believe you can charge a hidden battery


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## dieselss

absolute;1710957 said:


> With out the isolator the 2nd battery will never charge. You will have the power of both battery's with that relay in place.


So my factory dual batt setup that does not have an.isolator, won't charge the second batt? It's all in how you hook up the wiring


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## dieselss

Monroe74;1709919 said:


> The point is the plow will use the one battery while the truck would use the other battery. And since each of those batteries will discharge at different rates the alternator won't need to charge both at the same time.


Then your still only using one batt. You don't need an isolator.


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## absolute

dieselss;1711150 said:


> So my factory dual batt setup that does not have an.isolator, won't charge the second batt? It's all in how you hook up the wiring


I'm just telling it how it was explained to me when I had the same problem an what worked for me. If you have a better solution by all means let's here it!


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## 32vld

dieselss;1711150 said:


> So my factory dual batt setup that does not have an.isolator, won't charge the second batt? It's all in how you hook up the wiring


When batteries are hooked up in parallel to a generator both batteries will get charged.


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## dieselss

absolute;1711232 said:


> I'm just telling it how it was explained to me when I had the same problem an what worked for me. If you have a better solution by all means let's here it!


I did tell a better way and so did 32. Just hook the batts together and be done with it


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## Maine_Train

dieselss;1711613 said:


> Just hook the batts together and be done with it


Maybe it's safe to assume that "everybody knows" all the ins and outs of series vs. parallel etc., but maybe it's not all that simple. Maybe Fisher Engineering and other companies provide battery isolators for a reason, and the reason isn't "to make more money."

Here's an older thread with some more information. I don't think the guy who made the first reply has been on the forum for awhile, but I've always thought he was a pretty smart guy. I'd follow his advice. <http://www.plowsite.com/showthread.php?t=87015>


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## dieselss

I understand all the points about isolators. But now your charging 2 batts at 2 different rates instead of 1 batt at one rate. Or 2 at one rate. The whole point is to not drag dwn the main batt. High amp drain systems need these, ambulances, fire trucks, news vans etc... I'm just not seeing the need for it in the o.p. case


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## Maine_Train

dieselss;1711961 said:


> The whole point is to not drag dwn the main batt.


Agreed.



> High amp drain systems need these, ambulances, fire trucks, news vans etc...


I remember fire trucks and probably ambulances with the big rotary switches, Leese-Neville I think, with "OFF-A-BOTH-B" on them. Those were often mounted on the left side of the driver seat, so they could be switched off after the operator got out, and turned on as the driver was climbing in to go on a run. I think sometimes they'd use both batteries when starting the truck, and then switch to just 'A' or 'B'.
Now a lot of emergency vehicles stay plugged in, with a high-tech ejector socket that spits the plug out when the vehicle is started. (The non-ejecting ones didn't always work, even with the socket right behind the driver's door. {RRRIIIPPP!!!!} )

I started reading the thread (and the one I linked to above) because I've got _something_ going on with my '04 Silverado right now. I replaced the main battery last year, but even before that, I noticed if I left the lights and controller cables plugged into the plow side (MM2, three-wire), it would drain the primary battery while the truck was off, usually overnight.
Most recently when I've been plowing, raising or angling the blade causes a helluva draw on the electrical system. Of course using headlights and having the defroster on '5' just adds to the load, but I had one time when trying to raise the plow after the truck hadn't been running for very long actually stalled it. Had to drag out the hot-start box again. 

With the below-zero weather we've had until recently, the plugs were frozen together, so I just left everything plugged in, and put the float charger on the primary battery.
Gotta get up to the Fisher dealer and find out "what's up with that."


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## dieselss

What's your alt output? How old is it and the batt?


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## 32vld

People complain that their charging system can not keep up.

They need more amps.

You get more amp by keeping the battery fully charged by installing a bigger generator.

You get more amps by installing the biggest battery.

You get more amps by running two batteries in parallel.

Putting in a dual batteries and not using them together eliminates the getting the extra available amperage.

If the truck needs 100 amps to run. The battery has to put out 100 amps. The generator has to put in 100 amps to keep the battery charged.

It is easier on a battery when it is teamed up and each one only has to put out 50 amps. The batteries will not be worked as hard. So because each battery is flowing less current/amps their voltage drop will be less.

The single battery will have a greater voltage drop because it has to supply a larger current flow.

Amp/current is the volume of electricity flowing.

Voltage is the pressure/force at which the electricity flows.

A garden hose will shoot farther when you place your finger over the end of the hose. More pressure causes the water to flow with more force. same with electricity.

If anyone has heard a 6v engine crank over compared to a 12v they will observe that the 12v system will crank the engine faster. This is why auto company's switched over to 12v for easier starting and brighter lights. Voltage drops are important. Putting in a higher amp output battery works better not just because more amps/current is available but the increased amp flow happens with less voltage drop.

Running 2 - 12 volt batteries in parallel providing 50 amps each will have a much lower voltage drop. Thus the electrical system will perform better.

When temperatures drop and or battery age causes the ability to produce energy drops. This is why cold weather makes it hard to crank an engine.

Running dual batteries allows current to be drawn from two batteries. During cold weather one of those batteries may not be able to start an engine alone. Though between the 2 of them working together enough current can flow to start the engine.

Dual batteries keeps voltage drops to a minimum and help compensate for cold temperatures and battery efficiency loss due to age.

How many people sit for hours at a time running electrical accessories with the engine off. They can use an isolator.

Though if I had sit for extended periods with the engine off and electrical accessories on. I would rather have a manual switch as in the fire trucks. Where I can switch to A or B to keep one battery fully charged to start the engine. Then switch back to Both when the engine is running.


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## Maine_Train

dieselss;1712173 said:


> What's your alt output? How old is it and the batt?


Not sure on either one, except the primary battery is less than a year old. I think the secondary battery had just been installed when I bought the truck, but that was 12/2010.
If the Fisher dealer can't get a look at it anytime soon, the place where I get it inspected and have most of the "ordinary vehicle maintenance stuff" done will probably have a good tester for the electrical system. I need to go see them about an issue at the other end of the truck anyway. (Tailgate latch and hinge.)


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## Maine_Train

32vld;1713065 said:


> How many people sit for hours at a time running electrical accessories with the engine off. They can use an isolator.


Yeah, I'm way more conscious of that these days. The two-way radio, even solid-state, is always using "juice" while scanning. And don't even _try_ transmitting with it before starting the truck. Been there, done that.


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