# Battery to small



## alesv (Oct 19, 2013)

I have an 02 silverado i just put a 7 1/2 ft MM on.
The lights dim when positioning the plow. I was thinking of going with dual batteries when I discover the truck has a under size battery in it. The book calls for about 750 cca and there is a 570cca in it. I plan on plowing only about 3 to 4 hours per storm. 
My question is "When" I put the biggest CCA battery my truck will accept (i'm looking at a 800CCA /1000ca) will it be enough to handle it. Also the ALT is 105 amps
Thanks


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## grandview (Oct 9, 2005)

Just put in the biggest battery you can. If you want to move the plow around do it when you moving the higher rpm's will help.


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## dieselss (Jan 3, 2008)

Well the lights will dim a little. Thats normal. If your really worried you can also buy a small battery charger and plug it in before and after


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## Rc2505 (Feb 5, 2007)

Upgrade the alt. and install 2 batteries. I have done that on all of my trucks, and I don't have any problems. Lights, warning lights, plow, salt spreader, cb, wipers, heater, and radio all running at one time, and the everything works great.


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## jasonv (Nov 2, 2012)

The brightness of the headlights is related directly to the electrical system's voltage. In order for a battery to charge, the charging voltage (alternator) has to EXCEED the battery voltage, so you usually have 14-15 volt charging for a 12 volt battery.

The plow motor will draw more current than the output of the alternator, so when you're running the plow motor, REGARDLESS of how large the battery is, the net current will flow OUT of the battery, which means that the "whole system" voltage will drop by 2-3 volts minimum. The bigger the battery and higher the alternator's output current, the lower the drop, but the drop will ALWAYS happen unless your alternator puts out way more power than the plow pump draws -- which is never going to happen.

You can always see the 2+ volt drop by the headlights dimming.

Now if your battery is incredibly small and alternator output is low, the voltage drop will be greater, could be around 5 volts drop. Much more than that, however, and the vehicle's ignition will fail.


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## dieselss (Jan 3, 2008)

Anything that charges at 15 vdc is bad. It should never charge that high just fyi


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## Whiffyspark (Dec 23, 2009)

dieselss;1671902 said:


> Anything that charges at 15 vdc is bad. It should never charge that high just fyi


No it's not. 14.5 is the minimum you want usually


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## dieselss (Jan 3, 2008)

15 volts is high. 14.7 14.8 is about right
13.8 is sufficient


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## upplowin (Aug 25, 2013)

I have a 2005gmc 2500hd, and I have a western ultra mount, Its a two battery system with two 800cca batteries. It works good and the volts going down when you operate the plow is normal but should also recover quickly...I would just go with your set up, a new 800cca battery & see how it works for you. You should be able to go to any auto store in your area, and have them load test your bat/alt. Its free of charge and they will let you know if bat or alt needs replacing...


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## alesv (Oct 19, 2013)

Thanks for all the advice. When doing more checks the voltage drop as around 4 volts which is way to much. Also when I say the lights dim so does everything else like the heater and radio displays flickers.
I talk to my local Alt and Starter repair shop and he was telling me that the alt dont charge that much if any at an Idle (which is where we plow at) and putting a smaller pully on alt would in turn make the alt think its at 1500 rpm and it would put out maxamium amps. 
Also the battery that the previous owner put in is only 590 CCA and 710ca which is used in 4 cyl trucks. 
I'm am going to install the largest CCA Battery called for my silverado and install the smaller pully and see hoe that works before going to a 2 battery system. If I go to a 2 battery system I have to start with the correct battery anyways and install same make model and size.
I will post with results as I get them.
Thanks For everones input.


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## dieselss (Jan 3, 2008)

I personally would t do the smaller pulley. It's still only a 105 alt. Invest in a bigger alt and call it a day


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## jasonv (Nov 2, 2012)

alesv;1671951 said:


> Thanks for all the advice. When doing more checks the voltage drop as around 4 volts which is way to much. Also when I say the lights dim so does everything else like the heater and radio displays flickers.
> I talk to my local Alt and Starter repair shop and he was telling me that the alt dont charge that much if any at an Idle (which is where we plow at) and putting a smaller pully on alt would in turn make the alt think its at 1500 rpm and it would put out maxamium amps.
> Also the battery that the previous owner put in is only 590 CCA and 710ca which is used in 4 cyl trucks.
> I'm am going to install the largest CCA Battery called for my silverado and install the smaller pully and see hoe that works before going to a 2 battery system. If I go to a 2 battery system I have to start with the correct battery anyways and install same make model and size.
> ...


What 4-cly truck would you put a battery that small into?
Toyota Tacoma 4-cyl comes from factory with 750 CCA / 850 CA.

Don't go for the largest battery "specified". Go for the largest battery that will PHYSICALLY FIT.

Also, something even more important that current (amps), is the battery's RESERVE CAPACITY. This is a number that basically specifies for HOW LONG it can pour out a certain current, before it is dead. Even a battery with a fairly small current can run the plow pump adequately, but the larger the reserve capacity, the longer it can run the plow pump. Reserve capacity measures the number of minutes that the battery can output 25 Amps. Reserve capacity is conceptually similar to the [MILLI]AMP-HOUR rating that you are probably familiar with in dealing with things like cellphones. I.e., a 2000 mAh battery will keep your phone operational for twice as long as a 1000 mAh battery. Similarly, a 150 minute reserve capacity will run your plow pump twice as long as a 75 minute reserve capacity.


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## jasonv (Nov 2, 2012)

dieselss;1671914 said:


> 15 volts is high. 14.7 14.8 is about right
> 13.8 is sufficient


Yeah, because 14.8 is *so much lower* than 15, so it must be worth picking a fight over 0.2 volts...


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## coldcoffee (Jul 17, 2008)

The smaller pulley will generate more heat and decrease the life of the unit. Also, depending on the effectiveness of your belt tensioner, you could potentially cause belt slippage.

Also, some units have a temp sensor inside which lowers output in order to keep it from overheating. Once the unit reaches it's high end temp, the output will drop.


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## dieselss (Jan 3, 2008)

jasonv;1671982 said:


> Yeah, because 14.8 is *so much lower* than 15, so it must be worth picking a fight over 0.2 volts...


Yea it is. 14.8 all day long at 15 that's high. Testers generally start saying faulty equip at 15


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## jasonv (Nov 2, 2012)

dieselss;1672009 said:


> Yea it is. 14.8 all day long at 15 that's high. Testers generally start saying faulty equip at 15


Nope, not 14.8. Faulty if its over 14.79376.
But thanks for trying.
:waving:


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## dieselss (Jan 3, 2008)

Ok. Thanks for letting me know.


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## rjigto4oje (Oct 27, 2010)

I've heard some guy's running battery isolators


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## dieselss (Jan 3, 2008)

No real need for an isolator


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## JCByrd24 (Oct 19, 2005)

I highly recommend you start with just a new single battery, and that it be an AGM battery. I run a single Sears Diehard Platinum which are made by Odyssey, which are very well known and used by the military. I just read an ad in popular mechanics that Interstate is now making an AGM battery as well, probably Odyssey as well. They are more vibration and cold resistant, and much more tolerant of deep cycling and high current draw, which the plow motor will do. My stock AC delco battery that was only a couple years old (combined with GMs computer controlled charging system) was allowing voltage to drop low enough to cause ABS system message in the message center. The new battery fixed that problem and also reduced dimming. Also verify you're wires and connections are in good shape and connections clean. Any money you spend on batteries and alternators will not help if connections are bad and wires too small. I followed advice here and added an extra wire from the alternator to battery (fused), and upgraded the ground path as well. 

I would suggest you only really need a bigger alternator if you've added continuous current draw in addition to the plow motor, such as lots of lights, electric salter, etc. The plow motor is pretty intermittent and should not alone require a bigger alternator than you've got.


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## alesv (Oct 19, 2013)

This all great advice. And with everything said I'll start with installing correct battery and upgrading the wiring alt and battery cable


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## gasjr4wd (Feb 14, 2010)

Upgrading the charging wire coming from the alt. will do wonders. I also always upgrade the gound wires. From the factory, they are all too small even with just the low draw of the stock items. After installing a winch or plow or lights or sound system, all of these draw much, much more than the factory thought about.
Your battery is stupidly small... I always get a combo deep cycle and cranking battery, the biggest I can get. Think about the battery as a deposit of energy. The battery is only ment for starting. Everything is supposed to run off the alt once the engine is started. If the alt was big enough to handle everything, the size battery doesn't matter. The alt refills the battery after starting, and keeps it full after overloading the alt.


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## peteo1 (Jul 4, 2011)

I have a hard time believing anyone plows at idle. Put the right size battery in it and it'll help greatly. FWIW, I run a 7.5' plow with two batteries and have no problems. Like mentioned earlier, I run the heat, radio, plow beacon,etc and the truck run just fine. Good luck


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## dieselss (Jan 3, 2008)

Really. Ok. You need to watch other pple plow. That's how a lot of plow jockies do it


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## Whiffyspark (Dec 23, 2009)

dieselss;1672661 said:


> Really. Ok. You need to watch other pple plow. That's how a lot of plow jockies do it


Depends on if Youre running gas or diesel and which truck. Friends plow at idle in their diesels but my gas trucks will hardly move lol


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## gasjr4wd (Feb 14, 2010)

also depends on axle gearing, tire size, stick vs auto, transfer case gearing, etc. even with my little 4 banger and everything I still normally only spin just over 1000 rpms, sometimes less, maybe sometimes more. (I never use low)
I have noticed the more I angle side to side the faster I run down the battery, but I get things done faster. I am pulling more juice from the battery with the plow than my alternator is putting out. I also have a second heater box and have extra lights pointing out the sides and front. I very seldom backup any distance. Most guys angle the same side, push snow, raise then back all the way up. I spin around and angle the other way. This way I'm not traveling without pushing white stuff. It's just hard on the electrical system. When I am really low, I do keep it angled the same way and backup the entire way rather than turn around and/or I just keep it in first gear and spin the crap out of the motor for a few minutes. (a popular swap on my rig is going to a high amp, one wire GM alternator. on my list of things to do.)

Most alternators don't produce their rated amps until about 5000 rpms. It's like how a gas engine doesn't produce the max HP at idle, but at a specific RPM. It's at highway speeds that your battery gets most of it's recharge from the alternator.
Another way of thinking of it. All your electrical goodies spend ($) more than your alternator makes (income) and you are pulling out (spending) of the batteries (savings or using credit cards) than you have. (fed gov) 
Getting a second battery is a loan. You need to spend less (use less electric) or increase your income (bigger alternator).
payup


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## dieselss (Jan 3, 2008)

Rear end, stick, auto, t-case. How does that play into alt size and charging? 
A one wire alt, how are those h.o.?


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## peteo1 (Jul 4, 2011)

dieselss;1672661 said:


> Really. Ok. You need to watch other pple plow. That's how a lot of plow jockies do it


That's all well and fine if you're running a large diesel. When I drop my plow in 4-6" of snow my truck at idle doesn't move very efficiently. I've been at this for damn near 20 years, I've got a pretty good handle on how to go the job efficiently and without destroying equipment.


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## gasjr4wd (Feb 14, 2010)

They all control how fast the engine spins. Say you have two trucks that plow at the same MPH speed.
If you have smaller tires and have something like 5.38 gears you are going to spin the motor faster than if you have oversize rubber and say, 3.55 gears. The second truck with oversize rubber and 3.55's will spin the motor slower, making less electrical power. Not saying it's going to be a huge amount but you may be surprised. The first truck will seem like it has much more engine power (Mechanical advantage) and will have less issues running extra electrical goodies.
The faster the motor spins the faster the alternator spins and the more it puts out, recharging batteries and running lights, plows, winches, amped up radios, etc.
Truck/car manufactures design and size charging systems for what they are building, not for all the extras we add. (unless you option/order the larger alternator or duel alternators. some of the 'plow packages' include the larger alternators and such)

If you roll down the road (truck 1) going 65mph but your engine is spinning at 3000rpm's, the charging system is putting out more than (truck 2) also going 65mph but that engine is only spinning at 1200rpm's. (about where my diesel is IIRC) This is why you may have the same alternator on two trucks but each has a different size pulley. I4 engine vs V6 engine vs V8 engine or what ever...

check out something like the graphs on pages 4 and 6 on:
http://www.venselenterprises.com/techtipsfromdick_files/alternators.pdf
or "ALTERNATORS MUST TURN THE PROPER RPM IN ORDER TO FUNCTION" line in:
http://www.thebackshed.com/forum/forum_posts.asp?TID=2973


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## dieselss (Jan 3, 2008)

peteo1;1672798 said:


> That's all well and fine if you're running a large diesel. When I drop my plow in 4-6" of snow my truck at idle doesn't move very efficiently. I've been at this for damn near 20 years, I've got a pretty good handle on how to go the job efficiently and without destroying equipment.


What does dropping your plow in 4-6 at idle have to do with.the tea in China? You drop Your plow, you push. Hit pile. Reverse and raise plow. I don't see complications?


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## yardguy28 (Jan 23, 2012)

i must be missing something. why are so many guys concerned about there lights dimming while plowing? i've been plowing for 3 years now, 2 with an 8' super duty straight blade and last season ended with a 7'6" v blade. lights have ALWAYS dimmed. i could care less, they come right back up. doesn't hurt a thing.


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## gasjr4wd (Feb 14, 2010)

peteo1;1672798 said:


> That's all well and fine if you're running a large diesel. When I drop my plow in 4-6" of snow my truck at idle doesn't move very efficiently. I've been at this for damn near 20 years, I've got a pretty good handle on how to go the job efficiently and without destroying equipment.


Do you drop the plow while stopped, then go or are you already moving then drop the plow? Do you have a stick or auto?
A few times I plowed with the transfer case in low but didn't lock the hubs. Pushed great, just slow and I ended up shifting a lot.
Next time you are pushing 6" of the wet heavy stuff shift the trans case into low range and leave it.
I am putting a plow on my Diesel now but my history is mainly using a little Suzuki Samurai for plowing. I guarantee you have more engine then me.


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## gasjr4wd (Feb 14, 2010)

dieselss;1672809 said:


> What does dropping your plow in 4-6 at idle have to do with.the tea in China? You drop Your plow, you push. Hit pile. Reverse and raise plow. I don't see complications?


...says the guy probably running a diesel...
:waving:


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## dieselss (Jan 3, 2008)

gasjr4wd;1672870 said:


> ...says the guy probably running a diesel...
> :waving:


and your point is?? gas, diesel, again if you have the proper equip, know how to plow whats the deal? I have plowed for years with different gas engines and am now plowing with my diesel. wesport


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## gasjr4wd (Feb 14, 2010)

There is a difference in running a 4cyl gas and a I6 or V8 Diesel... You prob don't even notice anything in front of the truck do you?
Your 7.3 is a beast. Best Diesel Ford had...


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## gasjr4wd (Feb 14, 2010)

yardguy28;1672844 said:


> i must be missing something. why are so many guys concerned about there lights dimming while plowing? i've been plowing for 3 years now, 2 with an 8' super duty straight blade and last season ended with a 7'6" v blade. lights have ALWAYS dimmed. i could care less, they come right back up. doesn't hurt a thing.


Because some of us can run our batteries totally dead while plowing... lights go dim, engine dies, no start. Dead.

Like Bones said, He's dead Jim!


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## dieselss (Jan 3, 2008)

gasjr4wd;1672885 said:


> Because some of us can run our batteries totally dead while plowing... lights go dim, engine dies, no start. Dead.
> 
> if your running your batts totally dead while plowing, your doing something wrong then. I don't care what tk it is, IF you know how to conserve your electricity then your never gunna kill your tk. as long as your tk is even remotely able to handle a load like a plow


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## maxwellp (Feb 16, 2013)

I think a mountain has been made out of a mole hill here. Put on a High Output Alternator and a High capacity battery and be done with it. I run three Dodge trucks one is a Diesel others are Gas all have 200 amp Alternators. They will put out 186 amp at Idle. I have no power problems and do not give it a second thought. The two gasers only have one battery. I don't have to plow in low, spin the crap out of the motor or any of the other things that have been covered here.


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## REAPER (Nov 23, 2004)

Turn your lights off while plowing. 
Problem solved. Thumbs Up


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## jasonv (Nov 2, 2012)

dieselss;1672888 said:


> gasjr4wd;1672885 said:
> 
> 
> > Because some of us can run our batteries totally dead while plowing... lights go dim, engine dies, no start. Dead.
> ...


Yes and no. Generally, you want a battery of sufficient size that it doesn't drain so far in a job that you can't start the truck again. Do a job, battery runs down *a bit*, then while travelling to the next job, it charges back up. This is where people with severely undersized batteries have problems -- because you can't run the plow pump nearly as much before it drains the battery.

Another problem, which usually doesn't affect plow contractors, is having an old truck that remains on site for plowing. In these circumstances, there is no driving between jobs. Truck is started, plow, plow, plow, park and turn off. No matter how big the battery is, you'll run it down if you don't charge it occasionally. Not ideal, but does happen, and it isn't because you're doing something wrong.


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