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Does anybody's plow

Discussion in 'Commercial Snow Removal' started by MileHigh, Jan 3, 2008.

  1. MileHigh

    MileHigh PlowSite.com Addict
    Messages: 1,827

    Does anybody's plow slow down as you plow longer? I'm about to flush my pump, hoses and anglers, to get some new fluid in there, I thinking my system is leaking in water. What's the best way to keep that stinkin water out of my rig? What do you guys think this sounds like?
    (come on B&B..lets hear it)
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    It's not uncommon for them to get slower the longer you use them...

    Every time you move the plow it's pulling up wards of 150-200 amps from the battery/batteries, so unless you have one heck of a charging system it's gonna pull the battery/batteries down eventually, since the alternator can't replace the amperage as fast as your using it. Now a good system with a big alt will keep up longer, but you'll still be pulling it out faster than it can replace it. And, it takes time for the alt to ramp up the charging current every time you demand that 150-200 amps (the newer trucks are the worst for ramping up the current quick enough to recharge the battery from an instantaneous 150-200 hit). So about the time your letting off the controller, the alt is just getting up to capacity to supply the demand (late model Fords are especially bad with this) and as soon as you let off the button, the alt ramps back down since the demand dropped off.. You do this enough times, the alt "gets behind" and the battery gets pulled down. Plus, most times your running at a low RPM so the alt never puts out the full rated amps anyway. And to top it all off, the hotter the alt gets from the workout, the less amps it will make... so all this stacks up against you and your once fast lifting snow plow..

    Think about how many times you move the blade in an hours worth of plowing...a ton, so it's not too hard to see why they'll slow down after a while. Generally guys running mostly large areas don't see as much trouble with it since they're not running the plow as often as a guy that's doing tight/confined areas.

    An alt or a battery is not like a capaciter... but thats what a plow truck could really use... too bad it would have to be the size of the truck for it to be effective.

    The whole deal with adding an additional battery is to add to the reserve capacity of the system before they're drawn down by the plow. Your not adding actual power, your just making the "tank" bigger that your drawing from... no different than a gas tank. The bigger the tank, the longer you can go, but at some point your gonna have to refill it. The trick with adding batts is the same way, you want to add enough reserve capacity to get you through the job, but you still gotta refill them.

    I kept track of the plow movements one time a few years back with a 12v digital "cycle counter" on the under hood solenoid activation wire, and on my mostly residential route during a 3" storm I plowed for 4 hrs and then popped the hood to check the counter.. it read 408! So I had pulled 150-200 amps out of the battery over a 100 times an hour! And I plan my plow motions carefully just to keep any unnecessary load off the system in the first place. So it's no wonder why it's hard to keep the charging system ahead of the plow.
  3. MileHigh

    MileHigh PlowSite.com Addict
    Messages: 1,827

    Whoa. I had no idea that the battery was that abused while plowing. Looks like i need 2 big batteries.
  4. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Most guys don't..... if they did I think they'd understand why batteries and alternators don't live as long on a plow truck.
  5. 04superduty

    04superduty PlowSite.com Addict
    Messages: 1,354

    B&B that was a very good informative post on a vehicles charging system.
  6. snowman55

    snowman55 PlowSite.com Addict
    Messages: 1,071

    i will often switch to 4 low in order to get higher rpm thus increasing the alt output seems to help also all trucks have 2 gell cell batts
  7. DUMZ

    DUMZ Senior Member
    Messages: 153

    very good info B&B
  8. apik1

    apik1 Senior Member
    Messages: 253

  9. saabman

    saabman Member
    from Maine
    Messages: 70

    You have to be careful with an overdrive pulley if the truck spends anytime at normal/high engine RPM. It can cause the alternator to overspin. Better to get a HD Alternator that is meant to generate 80% of rated capacity at low RPMs and it will not get hurt at higher RPM.
  10. Mark Witcher

    Mark Witcher Senior Member
    Messages: 605

    Its also very possible that your pump motor is in need of a rebuild. I have had similar problem in past.
  11. MileHigh

    MileHigh PlowSite.com Addict
    Messages: 1,827

    I wouldn't doubt it.
  12. Petr51488

    Petr51488 Senior Member
    Messages: 265

    The newer chevy's have the dual alternators as an option. Pretty neat if you ask me.
  13. dieselss

    dieselss PlowSite Fanatic
    Messages: 11,392

    hey just readin the thread and i thought i would add my 2cents.
    the hd alts are a good idea. make sure you get them from a reputable store. heard some horror stories about pple getting low amp alts but got charged for a high amp one (happened to me from ebay)
    if you run dual batt's, its a good idea to get a splitter box.
    and B&B is right plan your plow movements ahead
    also check the front of the plow and make sure you don't have excess snow build up on it. that will deff. sllllloooooowwwwww it down!!
  14. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    If the motor is worn and pulling more amps than it should, it will definitely affect the load on the electrical system, and pull the battery down faster... so you want to keep a good, properly working motor on the plow to lessen the power draw that the system has to deal with in the first place.

    The overdrive pulley idea sounds good but it doesn't help as much as you think it would. Most Alta's are rated at 5000 rpm as the rpm when they put out max amps, and there usually already overdriven at least 4:1 on a factory system... so 5000 alt rpm, (which again is what rpm it would make the max amps at) would be approx 12-1500 engine rpm. So generally your not operating the truck at much below this rpm for very long, so overdriving it even more to get the last few amps of output out of it doesn't make much difference.

    The trick on the later trucks would be to "fool" the alt into responding to the amp demand quicker and keep it charging longer after the hight amp load is removed. But the field wire to ramp the alt up and down is totally controlled by the PCM so it's not as easy as it sounds. Technically speaking, you could control the alt output through the field wire manually with some type of adjustable rheostat that would allow you to control the voltage that the field wire would see but it'd just be another thing to baby sit while plowing.. and if you didn't keep an eye on the system, could damage the alt and over charge the battery fairly quickly, especially with a high output alt... neither would be good.
    Last edited: Jan 5, 2008