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Dual Battery Question

revrnd

By revrnd
in 2020-2026 Silverado HD & Sierra HD

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bruceb58 Enthusiast

bruceb58

Posted
Posted
9 hours ago, revrnd said:

 

That's similar to how I wired my 2nd battery for powering the winch. Not sure if it's still used, but I used a battery isolator like this:

Screenshot_20241121_095336_Chrome.thumb.jpg.579a32ed7a9bb85bc9ec54d48df917af.jpg

I could draw down the winch battery, but not affect the starting battery.

 

Do you think that the wiring/electronics would allow power to flow from the aux' battery during cold temp' starts? 

 

The truck includes the True North Pkg, but the 220 A alternator & aux' battery are not part of it.

 

 

 

Surprised that actually works due to the diode voltage drop and how the smart alternator is controlled.

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rjgvt
rjgvt

The aux battery on my truck supplies 12v to the trailer connectors at the bumper and inside the bed. My truck has the plow prep package and fifth wheel options. I used the bed connector to provide pow

lineman1234
lineman1234

As i really wanted to custom order my WT but no dealer had any clue on when the regular cab line would run, i found one 186 miles away. Very close to what i wanted, or close enough. ( I LOVE my WT ) s

rjgvt
rjgvt

Those are the upfitter switches. That option was not available for the 2024 AT4 and Denali.

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revrnd Senior Enthusiast

revrnd

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24 minutes ago, bruceb58 said:

Surprised that actually works due to the diode voltage drop and how the smart alternator is controlled.

This was back in the early 80s w/ a '82 K15. Alternator was the ubiquitous Delcotron. I'm not sure how 'smart' those units were compared to present day alternators.

lineman1234 Enthusiast

lineman1234

Posted
Posted
1 hour ago, bruceb58 said:

Surprised that actually works due to the diode voltage drop and how the smart alternator is controlled.

From looking up the 2024 L8T 6.6 gasser, it is said to NOT, have a smart alternator. 

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revrnd Senior Enthusiast

revrnd

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Posted
18 minutes ago, lineman1234 said:

From looking up the 2024 L8T 6.6 gasser, it is said to NOT, have a smart alternator. 

So how does that affect the aux' battery in a gasser vs a Dmax?

lineman1234 Enthusiast

lineman1234

Posted
Posted

The very cool thing about NOT having a smart alternator, is its cheap and easy to rebuild. 

 

My past diesel, the alt went, having never rebuilt an alternator before, i did it on the pick=nick table of a campground, its easy. Why. The sommmbiaatches wanted to give a lousy $55 core charge on a $365 alternator, so i just rebuilt it for a spare, for myself or friends that had a ram, then i gave it away when i sold the said diesel last year. 

 

The rear small barring went, so a rebuild kit is front and rear barrings, and a rectifier thingy, thats it. 

 

 

lineman1234 Enthusiast

lineman1234

Posted
Posted
1 minute ago, revrnd said:

So how does that affect the aux' battery in a gasser vs a Dmax?

A gasser and a diesel cant be compared as a battery goes. Nor how they are wired to work. The diesel doesnt have an auxiliary battery, it/they have 2 deep cycles for the load needed for starting the high compression motor and the high amps on the glow plugs/grid heater. 

    A gasser isnt deep cycle batt/s. Its normal car style.  

 

From my limited knowledge. The dual batts in the gasser is for the snow plow usage only. 

    I looked into what installing the kit i have in the 2 bags of stuff that came with the pickup and looked online for instructions on how to install it and its quite involved as what it does when high demand is needed in plowing. Its not controlled by the alternator, but by the/one of or multiple pickup computers. 

 

As far as the truck camper part of the plow/camper kit goes. A truck camper is no different than any other camper as far as charging or keeping the camper batts topped off. Its the front end more lbs available part that is the truck camper part. The bigger alternator isnt going to let more amps flow to the 7 way plug/s to charge a truck camper or a camper that its rated to do/for.

lineman1234 Enthusiast

lineman1234

Posted
Posted

Growing up in the top of MN, years ago it was called a winter package. Consisting of a bigger batt, frost plug heater, and more coolant so it didnt freeze. -40f isnt uncommon, not including the wind chill, so a winter package was wanted for colder areas. 

   A second batt couldnt hurt, but,,,,, if tied together like i have mine now, if one crapped out, it would drag the other down as well. 

 

Thinner and better oil now a days as with fuel injection vehicles start much better than the older days. 

bruceb58 Enthusiast

bruceb58

Posted
Posted (edited)
5 hours ago, lineman1234 said:

From looking up the 2024 L8T 6.6 gasser, it is said to NOT, have a smart alternator. 

The fact that the ECM controls the charging/output of the alternator makes it a smart alternator system. That is the definition of a smart alternator!

 

This is all according to the factory service manual. It's all explained in the "Starting, charging and Low Voltage Energy Storage" of the factory service manual if you want to look it up!

Edited by bruceb58
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lineman1234 Enthusiast

lineman1234

Posted
Posted
7 hours ago, bruceb58 said:

The fact that the ECM controls the charging/output of the alternator makes it a smart alternator system. That is the definition of a smart alternator!

 

This is all according to the factory service manual. It's all explained in the "Starting, charging and Low Voltage Energy Storage" of the factory service manual if you want to look it up!

MY GAWWWWD you dont give up on your silly being wrong. 

 

A search between what is the difference between a smart alternator and non smart is explained. As well as the reason the tree huggers got there way and a smart alternator is used, on some vehicles . But ( not ) on the gas guzzling polluting cheby HD. 

 

Have your alternate username/personality chime in and back your wrong comments up. 

Pryme Senior Enthusiast

Pryme

Posted
Posted (edited)

This video says if your vehicle has this module connected to the negative terminal on your battery then you have a smart alternator. I have no idea but take it for what it’s worth. I’ll have to check my 22. I don’t believe there is a small module on the neg post though. 
 

also I read that if you’re vehicle has a smart alternator, a gauge(like the sg3) will show big swings in voltage. Mine is pretty much solid in the mid 14’s 

 

Might be different on a 24 since they changed a ton on those models. 

Edited by Pryme
bruceb58 Enthusiast

bruceb58

Posted
Posted (edited)
58 minutes ago, lineman1234 said:

MY GAWWWWD you dont give up on your silly being wrong. 

LOL...I was an EE for GM at one point in my career, We had smart alternators for over 20 years!

 

All you have to do is monitor the voltage of your truck and you can see the variable voltage occurring at various times! Seriously...it's very easy to see...even a caveman/lineman can see it.

 

From the Service manual

 

image.thumb.png.974f61ff382c676440999f76d0ccfb70.png

Edited by bruceb58
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revrnd Senior Enthusiast

revrnd

Posted
  • Author
Posted
12 hours ago, lineman1234 said:

A gasser and a diesel cant be compared as a battery goes. Nor how they are wired to work. The diesel doesnt have an auxiliary battery, it/they have 2 deep cycles for the load needed for starting the high compression motor and the high amps on the glow plugs/grid heater. 

    A gasser isnt deep cycle batt/s. Its normal car style.  

 

From my limited knowledge. The dual batts in the gasser is for the snow plow usage only. 

    I looked into what installing the kit i have in the 2 bags of stuff that came with the pickup and looked online for instructions on how to install it and its quite involved as what it does when high demand is needed in plowing. Its not controlled by the alternator, but by the/one of or multiple pickup computers. 

 

As far as the truck camper part of the plow/camper kit goes. A truck camper is no different than any other camper as far as charging or keeping the camper batts topped off. Its the front end more lbs available part that is the truck camper part. The bigger alternator isnt going to let more amps flow to the 7 way plug/s to charge a truck camper or a camper that its rated to do/for.

On the bold true, it's been like that since the days of the Olds 350 diesels in pick ups.

 

I can see a gasser being equipped w/ a 2nd battery if it has either the plow prep and/or trailering pkg. If the aux battery is just wired to supply 'ancilliary' loads, isn't that a bit of overkill?

 

12 hours ago, lineman1234 said:

Growing up in the top of MN, years ago it was called a winter package. Consisting of a bigger batt, frost plug heater, and more coolant so it didnt freeze. -40f isnt uncommon, not including the wind chill, so a winter package was wanted for colder areas. 

   A second batt couldnt hurt, but,,,,, if tied together like i have mine now, if one crapped out, it would drag the other down as well. 

 

Thinner and better oil now a days as with fuel injection vehicles start much better than the older days. 

 

RPO Z49 Mandatory Canadian Base Equipment Modification has been around in the 70s. In the past (as explained to me by my father) it included those items, plus I think a heater (I recall reading an article about a truck w/o a heater & radio in some place in AZ or NM as neither was needed). I'm sure the metric instrumentation and bilingual labelling was/is part of it. I looked in my in plant model/option guide from 1980. No breakdown (like some options) for what Z49 included.

 

That all being said, both my 2017 (with VYU) & my 2024 (w/o VYU) show the block heater as an option. You would think that trucks being built for the Canadian market and/or equipped w/ the 'True North' pkg, would include 1 as std equipment. 

 

 

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jake111 Enthusiast

jake111

Posted
Posted

Well, officially "smart" or not, when I hooked up my slide-in camper to the trailer 7-way, I immediately noticed a BIG difference in the way it charged the house battery.  Or maybe I should say, how it didn't...  I was sitting in park and the alternator was putting out well under 13 volts, too low to trip the camper separator, so no charging.  Yes, I revved it up.  No, it didn't help.  I saw the voltage varying quite a bit.  I know of no "unsmart" alternator that behaves like this.  Certainly, none of my older cars and trucks did this.

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revrnd Senior Enthusiast

revrnd

Posted
  • Author
Posted
18 minutes ago, jake111 said:

Well, officially "smart" or not, when I hooked up my slide-in camper to the trailer 7-way, I immediately noticed a BIG difference in the way it charged the house battery.  Or maybe I should say, how it didn't...  I was sitting in park and the alternator was putting out well under 13 volts, too low to trip the camper separator, so no charging.  Yes, I revved it up.  No, it didn't help.  I saw the voltage varying quite a bit.  I know of no "unsmart" alternator that behaves like this.  Certainly, none of my older cars and trucks did this.

 

Is that thru the plug on the LH side boxside or the 1 on the bumper?

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