04 chev, dead dual batteries, install cutoff?

[stargazer]

When this chev '04 cab chassis dually was new I found both batteries dead once. This has happened only a few times, no explanation except maybe too many computers. There is an auxillary roof light so it's not that circuit.

Well, it just happened again. Dead as a doornail. :headwall My plow is not even attached. I was just about to buy new batteries for this winter but I don't want to have them killed as soon as I get them - or any other time. Too many electronics to expect to solve something that happens so rarely.

My question, is there a good way to cut off the batteries that won't add too much resistance to the start up and plow? Does a battery cutoff solenoid add a lot of resistance? Is there a good manual switch that would be better? Can I cut off the ground (hate to cut a ground wire) since the positive post has so many connections (two plow setups, will have an electric sander at some point)? Should I cut off both batteries - they are connected in parallel with a 2ga. battery wire - or should I isolate one of them and cut off the other?

Or any other plan that you might have come up with and that I might not think of? Thank you for your ideas, any and all considered and appreciated,

[Pickering Snow]

Well you dont state gaser or diesel but ill assume its a Diesel, so using a Isolator wouldnt help much because the truck still wouldnt have enough cranking power to start a diesel on one battery.

The correct way and i know its intermitt is to perform a draw test to find the culprit. The allowable draw for that truck is just under a 1/4 amp . One thing i have to do this time of year with the wreckers and it works the best for my problem is some wreckers set for a couple of days without moving this causes issues when starting so i have Battery tenders installed on those trucks , a battery tender is a small charger that you hook to the battery run the cord threw the grill and it keeps the batterys at the correct charge rate its only on if the battery volts fall below a prescribed amount. These units are about 40bucks and there a life saver.

[Fastjohnny]

Fred, which bat tender do you use, I've felt like some in the past tend to trickle charge all the time and burn out the bat?

[Pickering Snow]

John

Same thing here when i was using Schumakers but since i switched to Vectors no problem. When its cold i know my 12ton IH the unit is on more than its off however again it still has the stock batterys in it.

For me using these is a life saver since average time to get enough juice to a DT466 to start can seem like forever, My Eta's have to be reasonable so if they dont start iam screwed. Still working on getting a gang pole set up at the new place kinda looks like a scene from Chevy Chase Christmas Vac right now with all the trucks plugged in.:D

I have never burned out a set of batterys using them but i sure have lost enough from them running dead and feezing. With the 6and7 trucks using 200 dollar a piece batterys cost i have to keep them charged.

[sonjaab]

Fast............there was a TSB and a warning on the VYU plow
prep. equipped trucks with a caution to make sure the roof
beacon switch was not left on thus draining the batteries.

[Firstclasslawn]

Take a digital volt meter and measure amp draw while the truck is off to EVERYTHING running off your battery. You WILL come across at least 1 cable with some draw on it. Figure out what the cable runs to and fix the problem!!! I just dealt with this on one of my trucks. My cable with draw on it was the "factory" power cable that starts the truck, runs the interior lights, ect. All my plow/salter wires read 0 amps. I was only drawing 1.01 amps on the truck cable with the interior lights on. With those off I was drawing .1 amps. I then started pulling fuses out of the fuse box. Pull one, check amp meter, replace. I eventually found my problem. That truck has a boss blade with a old boss control box. It has no on/off switch! So the plow system was "powered" all the time. I changed that wire to a circuit that is switched on/off with the key and we are golden now!

[stargazer]

Well you dont state gaser or diesel but ill assume its a Diesel, so using a Isolator wouldnt help much because the truck still wouldnt have enough cranking power to start a diesel on one battery

I was in a hurry yesrerday morning. As soon as I started driving I thought -****! - I didn't even put the model or the engine. Sorry about that. I was out of cell phone coverage, never mind internet.

The truck is a gasser, the 2nd battery not factory. It was installed @ my request before purchase by either the dealer's commercial truck center or the company that installed the aluminum dump body and plow.

The model is an '04 chevy cab chassis 4x4 3500 with 8.1 liter gas and an allison transmission.

The "battery dies" problem may occur once in 6 months or more, totally random. It was a warm night when it just happened. I'm not talking weak, I'm talking dead. I have a similar '02 with two batteries, factory, they are not directly connected in parallel. No problem, even when it sits forever. Origional batteries in it.

Due to the extremely intermittant nature of the problem I imagine somthing is occasionally sticking on. I can't test daily for months on end. It is not the roof light relay, first thing I did was wire it up to lights. I'd love to solve the problem but realistically at this point I want to protect the new batteries I'd like to get from total discharge. No one out there has a battery cut off installed?

Fred, the battery maintainer sounds like a good idea if it has the power to keep up with whatever the drain is. Last year I installed a post with power between my trucks' parking spots. So that would be easy. I'll at least do that while looking for a solution.

I just checked, 12.68 volts on the primary battery @ 20 degrees F very heavy frost. Been sitting all day and all night. No switches touched since it went totally dead overnight in the warm. :headwall

Firstclasslawn, thanks for your description of how to check, I'll probably try it when I install new batteries. But I have little hope for catching the totally random drain.

[Pickering Snow]

Since its a gasser you can install and fashion a Isolater similar to a Rv you will have to set it up so your system can be switched on when plowing, the Iso protects the start battery acts has a one way valve to stop the start from getting run down when the engine is running both start and coach will recharge. Or run a Batt Tender. If you want correct way to preform a Parasetic Draw let me know ill post it but honeslty like i said and you know with it being that intermitt for now it would be imposs to find.

[stargazer]

In the interest of science and the quest for knowledge - plus wanting to fix the PITA, I checked the voltage again early this am.

Two days ago I started the truck just to make sure that the voltage reading wasn't superficial, that there was bottom end (cranking power). Started fine.

Let it sit that day and all night with howling winds at 20 degrees. Next day it never got out of the 20's, and last night it was 10 degrees most of the night and breezy. Voltage reading this am was 12.65 volts. Checked a few other batteries and they were all around 12.6, the new big tractor battery was 12.86 volts.

Fred, that battery tender idea is looking more attractive all the time. Definitely not a slow steady loss. Maybe I don't even need a new set of batteries, just a tender.

I had one thought, the electric dump body is not ignition switched, it is powered all the time. Not much to it so I don't know what could stick on, but whatever it is totally kills two batteries so it must be a fairly big draw when it happens. Charger needs to run awhile before it even begins to charge at all, then slowly builds up to maximum rate.

[stargazer]

Moderators, this is no longer urgent, feel free to move this thread to the best location, thank you.