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Discussion in 'Chevy Trucks' started by markq, Sep 29, 2005.

  1. markq

    markq Member
    Messages: 47

    I kno that there are a TON of posts in here about hooking up dual batteries, but I have a little different question.

    Instead of wiring a second battery into the entire trucks electrical system, can I add a second battery just to power the plow?

    Obviouslt I would have to hook it up the alt to keep the bat charged, but I dont know if this will work or not.

    I'm going to try and attach a pic so you can see kinda how I envisioned doing this. Let me knwo if this wont work for any reason.

  2. markq

    markq Member
    Messages: 47


    Dont everyone respond at once!

    Please help! I need to get this done in the next week or so!!!

    Anyone with any input would be GREATLY appreciated!


  3. Seamus

    Seamus Member
    Messages: 43

    I'm by no means a genius when it comes to electrical systems, but I can't see any logical reason why what you have in mind won't work as long as your charging system is up to task for two batteries. However, I also can't see any logical reason to not hook the batteries up in series as one would normally do. Anyway, as I always say," It's your story and you can tell it however you want." Good luck!
    Seamus :drinkup:
  4. calhoun

    calhoun Senior Member
    Messages: 165

    It is called an isolated battery and there are threads about it here. I don't know why you would want it hooked this way for plowing. An isolated set up is more for powering stuff that is used with the truck not running. Duals hooked together is a better system for plows.

    TRUE TURF LAWN Senior Member
    Messages: 290

    you don't even need two batteries. yes it nice to have two but ones fine i wont do it. :waving:
  6. GetMore

    GetMore Senior Member
    Messages: 179

    Your drawing still has the batteries connected. They connect at the alternator.
    If you really wanted to keep them separate you would need to install an isolator (as mentioned above). An isolator has diodes (electrical one-way valves) so that power can go from the alternator to the battery, but not from the battery back to the alternator, and then to the other battery.

    The disadvantage to using an isolator is that if you use the plow heavily and have other drains (like an electric sander, lots of lights, etc.) connected to the plow battery you will run low on power quicker. If instead you have both batteries connected (even if just at the alt.) then you will have much more reserve power and the alternator will not have to work as hard.
    The problem with having two batteries connected together like this is that both must be equal, or they will "fight" each other and drain when sitting. By equal I mean both have to be as equal as possible: same capacity, same brand, same build date. Ideally you should take two side by side from the production line.
  7. Robhollar

    Robhollar Senior Member
    Messages: 766

    An isolater isnt going to help this at all.. If you want to use 2 batteries 1 for just the plow your going to use a second relay and a high cap diode.You would hook up the battieries together using the high cap diode. This would be for charging the 2nd battery. The diode will allow the 2nd battery to charge but not allow the truck to pull power from it. Now taking a second lead from the 2nd battery go to a relay then to the plow motor. Thus you would be isolating the truck from the 2nd battery untill you hit the switch for the plow. Hope this helps.......Rob
  8. GetMore

    GetMore Senior Member
    Messages: 179

    Robhollar, that is an interesting idea, a combination of the isolator and solenoid systems.
    Hooking the diode in line is the same thing as hooking up an isolator. That's really all they are.
    Using a relay (for some reason they are called solenoids when they get to that size, I don't know why) to tie the two batteries together when using the plow seems like a good idea.
    This setup should eliminate the possibility of the dueling battery syndrome while allowing the use of mis-matched batteries.

    The bad part is that the diode will drop the voltage going to that second battery, so it will not be fully charged. When the two batteries are connected this will be an issue. I don't think it will be a big issue, but it has the potential to be a problem.
  9. Robhollar

    Robhollar Senior Member
    Messages: 766


    Well to start off I give you about the voltage drop across the diode but Im not sure on how much drop your going to have across it, but if its a prob then yes you could use an isolator. At which case then you could use the second " solenoid " to introduce the additional current to the circuit.....Rob
  10. sonjaab

    sonjaab PlowSite.com Addict
    Messages: 1,425

  11. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Or you could go with a big High Output alternator and a big battery.
    You can get off the shelf alternator's that put out 150->200 amps.
    ( an alternator only puts out near 1/3 of rated output at idle )
    You have to upgrade your wireing to the battery / batteries.
    An automotive electrical shop can upgrade your alternator for about $1.25 an amp. A 900 cold cranking amp battery adds a lot of reserve too.
    You need to have an isolator setup or you get battling battery syndrome, one battery discharges into the weaker one,then it reverse's,till both are low.
    The big chain auto parts store have the isolator setup's in stock.
  12. maintenanceman

    maintenanceman Member
    Messages: 32

    I think what markq is looking for is a completely isolated system for the plow. I installed a sytem on my 85 gmc that is completely isolated from the trucks circuit. The reason for this was because the alternator used on this year truck comes with a single v-belt pulley which doesn't have the friction forces to turn the pulley when the alternator is at full load. Basically when I used the plow the belt would slip and I burned a lot of belts off. We solved this by installing a second alternator and battery. The system works extremely well. I even added a selenoid between the two batterys so that if one alternator or battery went down, I can switch to the other. If you are interested i can upload a picture of my setup.
  13. markq

    markq Member
    Messages: 47


    This is exactly what I want......I want to keep the plow setup COMPLETELY isolated from the trucks electrical system. This way I don't have to worry about lights dimming, or screwing anything up with the truck electrical system. I know that if installed properly that it shouldn't mess anything up, but I don't trust myself doing it, and I don't trust anyone else to do it either.

    As for just getting a HO alternator, and larger batt, I would rather not go that way because then you have to change the batt cables, and I would be worried that the electrical system in the truck wouldn't be able to handle the much larger current without a ton of upgrades.....I definitely don't want to fry my wiring, or the CPU.

    Anyways, maintenanceman....if you have a picture of your setup that would be great.....and anyone that knows where I can get another alternator bracket that will bolt up to my truck, let me know.

  14. maintenanceman

    maintenanceman Member
    Messages: 32

    I thought I had a picture on my computer but I don't. I'll take another one and post it Tuesday. It is very simple to wire in using a gm internally regulated alternator, the hard part is mounting it. Chances are that you will have to build or modify a bracket to mount the alternator. On my truck I removed the air conditioning and mounted it there. This seperate system has worked quite well as the lights on the truck don't dim and both alternators are only 85 amps.
  15. murphyslaw

    murphyslaw Senior Member
    Messages: 443

    the reason why ppl like me and most of you use two batteries is to increase the amperage cappacity of the electrical system. by using an "isolated" battery you have not improved the performance of the plow because you are still subjecting it to a "single" battery. and this will still put a significant load on your electrical system cause the alternator will be working full load on that battery and leaving the rest of the truck "to fend for itself" this will not improve the power condition of your truck and i dont think you will find any difference in the was your electronics work. sry abit of babbaling on but thats just "MHO"
  16. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Like I said Big Alternator and a Big Battery---> Done, Bang problem solved!
    If you don't have enough amps coming in you will always being playing catch-up.
    (It only put's out near 1/3 it's rated amps at idle, full near 2K )
    Whenever you run lights,Heat and an Electric over Hydraulic Pump you drain reserve from the battery / batteries. If it's not being put back fast enough eventually the battery / batteries give up.
    Last edited: Oct 8, 2005
  17. OneBadDodge06

    OneBadDodge06 Senior Member
    from Iowa
    Messages: 771

    I think I'll invest in a diesel generator in the back of my truck. I have as many lights as the Ecto 1 on ghostbusters along with my portable fridge and microwave. :cool:
  18. Two Batteries

    It's actually better to hook both together! Because a plow (or in my case and front AND back blade) can really draw a battery down, and if you draw it low a lot, then you kill the battery fast. So really you have two options..... Two batteries or one deep cycle battery. (an optima yellow top $130). I NEED two. WIth just one hooked up, my plows will cause my volts to drop low enough to shut my radio off.
  19. OneBadDodge06

    OneBadDodge06 Senior Member
    from Iowa
    Messages: 771

    does anybody really notice the difference running a giant alternator and having 2 batteries? My lights dim no matter what.
  20. I do

    With only one battery My radio shuts off, with two my lights just dim a bit!!!!. But i am running a backblade too, so i am probably drawing about double the power you are!