2006 Denali Battery type

Jkb242

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May 19, 2019
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I have replaced the battery on this vehicle a few times but wanted to be certain before doing so again that I get the correct battery. When this vehicle was made I’m pretty sure it was not equipped with an AGM battery, as they were not in production at that time. I believe AGM batteries also require a different charging control system. It seems Costco batteries are all AGM and believe I have been given one of these in recent years which seem to fail in less than a year. Again I do not believe AGM batteries are compatible with a 2006 model.

Anyone know of a source that sells the non AGM batteries that are OEM or equivalent correct battery?

Thanks!
 

Mooseman

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Dec 4, 2011
25,257
Ottawa, ON
These trucks did come with regular lead acid batteries. AGM are supposed to be better and do not require anything special to use them. I personally don't think they're worth the extra expense. Just about anyplace that sells batteries have regular batteries. Although Costco does sell AGM, they should also sell regular ones (they do here in Canada).
 
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Reprise

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There's one scenario where an AGM comes in handy for these trucks, IMO, and that's if you seldom drive the vehicle. That's because AGM batteries discharge more slowly than the conventional flooded lead-acid (FLA) type.

They also feature less resistance when cranking (found this out just today, as it turns out), and they also can be regularly discharged to about 30% without harm (vs. 50% for an FLA). Finally, since they're a true 'sealed' battery, they can be mounted in any orientation (even upside down!), which is nice if you want to do a trunk relocation in a car, or install in an RV, etc. And if you order from someone online, that's a benefit when it comes to having it shipped, as well.

Where compatibility issues rise with our trucks is in the charging algorithms... AGMs are 'supposed' to be charged at a slightly lower voltage / rate than an FLA (think BBQ... 'low and slow').

I said 'supposed', because our trucks can't really discern between the two, so they charge the battery as if it were an FLA (as high as 15.x volts, depending on how discharged it is.) Our charging systems do have *some* intelligence built-in, but not to handle AGM batteries 'properly'.

Is that bad? Jury's out, as far as I know -- I bought one a year or two ago, and haven't had issues with it, but I'll be the first to say -- that's not a long time. The reason I bought it is because my Envoy does sit for fairly long periods (two weeks or more; especially this past year). I've not noticed any audible difference in cranking, after it sits (but it doesn't really crank any differently than the 'old school' FLAs did, either).

So... if you're driving the vehicle even semi-regularly, a FLA would be just fine. Your pick of what brand. I used to get the WalMart batteries because if I were out camping, and one went south, there's a WM just about everywhere, when I'm away from home, and they carry batteries in just about every WM (even the ones without auto centers).

Unfortunately, I had two of their 'Maxx' batteries go bad (one in the Envoy, one in a Sierra), so I swore them off going forward. I have one left (as a warranty replacement), and I keep a Bluetooth device attached to it that tells me its state of charge (SoC) at least once per day - when it gets close to 11.9 V (the 50% mark), I break out the charger. But when it goes, I'll give serious consideration to another AGM (especially if I can find one on sale, like the current one in the 'Voy.) What I've learned (?) over time, and using that monitoring device, is that the WM batteries I'd been buying have a faster discharge rate than some other brands. They're made by Johnson Controls, who makes batteries for many other labels, so I don't know exactly why the WM batteries don't hold charge as well (except maybe there's some sort of testing of lead plates, and the WM contract allows them to use the 'marginal' ones.)

Anywho...as far as what type to get... since you have the V8, like I do, something in the 800 CCA range is good (the OEM was about 650 CCA or so, as I recall). It's a Group 78 -- but if you don't like side-terminal batteries, you can get a Group 34, which is the exact same battery, except that it's a top post. You can get a set of terminal adapters that convert the wires in your Denali to top post, and use a Grp 34 just fine, if you prefer.

There are some batteries that even have *both* terminal types (they'll be listed as a '78/34') -- if you get one of these, I'd keep the terminal protectors on the set you don't use, to protect against accidentally shorting the battery out, if it comes into contact with something it shouldn't. Other than that, they're just fine to use.

When you get your new battery, try to get one as 'fresh' as possible -- there's usually a sticker or tag that tells the manufacturing date. Less than six months old from 'today' is good (and about the most time from 'new' to accept one, unless the store can assure you that they charge their stock at least once a month (the 'Batteries and Bulbs' chain does do this; I've seen it in their stores. WM... well, they don't, as you'd expect)).
Less than 3mos from mfg date to installation is even better. And I do top off any battery I buy with a charger, before installing it in a vehicle. That way, I know it started out as optimally as I could get it, and my alternator doesn't kill itself trying to revive one that might be almost dead.

There are a couple of other battery types - Gel cell, and Lithium. The Gel cells *do* require specialized charging, and the Lithium are really expensive, especially for this application. So I'd stick with the FLA or AGM; spend the difference on a decent charger (e.g.; one that has an AGM setting, if you do decide on that format).
 

Chemman

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Jul 13, 2013
35
Maryland
I purchased a SLA Group 78 battery at Costco for my 1999 Silverado about 2 weeks ago, and it had a 12/20 sticker on it. I did not see any AGMs at the Costco where I purchased it.
 

northcreek

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Jan 15, 2012
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Go to Auto Zone and get what they recommend for your vehicle with the best warrantee. If it fails they are great on honoring the War. and they have stores on Mars. Their batteries are no better or worse than what anybody else sells...:twocents:
 
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HARDTRAILZ

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Nov 18, 2011
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I love my AGM over 5 years of extra stereo, winch, lighting, and general abuse.

They require no changes at all and are better built batteries. If budget is not a concern...get one!

Regular batteries work fine for us, but they are better if you really research them and have an extra needs from a battery.
 

DocBrown

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Dec 8, 2011
501
Funny this conversation comes up now. I just bought a very low mileage 2016 Silverado LTZ a few weeks ago. We had sub zero weather over the weekend and the truck turned over slow. I'm putting a new AGM battery in this afternoon. After lots of reading yesterday this seems like a good option, it has lots of power drawing toys and I tow a travel trailer. From everything I read they should be fine with most modern vehicles. And they are supposed to have excellent cold weather performance.

But 2006? Might be a little old. But I also found postings on other forums where people with older trucks are using them without any issues.

The biggest issue I could find is that when one drops below it's functional voltage most battery changers won't charge it and flag the battery as dead. And then the owner thinks it's a bad battery. AGM batteries can be recharged when they are very drained and they will still be fine. As Reprise said they need to be charged with a charger that is compatible with AGM.

One thing to note. Pretty much every battery I've looked at is only a 3 year warranty. Some with 2 years. None with a 5 year. With the power demands of modern vehicles, I don't think the manufacturers want to stick out their necks anymore.
 

Reprise

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One thing to note. Pretty much every battery I've looked at is only a 3 year warranty. Some with 2 years. None with a 5 year.

Check out Batteries & Bulbs (formerly Batteries Plus). That's where I got my Duracell AGM, and it had a 5yr warranty. I don't know if they've changed since I bought it, but I know my warranty is 5yr on that battery.

As an aside... I went to start the Sierra again today (the one with the WM lead-acid that drains quickly), and decided to also start the Envoy (which has the AGM). Temps here have been very low (daily highs from -2F to +2F; nightly lows about -10F, on average). Most of you are probably feeling the same, thanks to the 'Siberian Express' sitting lower than usual, right now. At least it's not a 'Polar Vortex'; then we'd be at about -30F, here.

Anyway... Just in the few days between my other post on the Sierra... 3 days ago, I charged it from about 11.89v up to 12.37v in about 30min or so, with the truck's alternator.
Today, it was back down to 11.80v, per the BT monitor, so I trudged out again to give it another charge. Noticed it cranked slower; the monitor showed its cranking voltage to be 7.93v (10.0v or better is considered 'good').

The above isn't to promote the AGM over the FLA, but to illustrate how 'marginal' I consider that WM battery, and that it's worth a few extra $$ to get something better.
BTW, I started up the Envoy as well, since I was out there (and I wanted to move it) -- no cranking issues with it, at all (I don't have a monitor on it, like with the WM battery).

With the power demands of modern vehicles, I don't think the manufacturers want to stick out their necks anymore.

I've read that it won't be long until you start seeing 48v electrical systems in autos; with everything that goes into the newer vehicles, the 12v systems are just about at their limits, now.
BMW has been using AGMs in their vehicles for a little while now, and when it's time for a new one, the AGM is a 'required' replacement, IIRC (they have intelligent systems that recognize & optimize charge). I think the replacement battery has to be installed with a high-end scan tool, too (again, BMW, so... )

I think I saw a year or two ago that someone has already done a 48v system in a current production vehicle (forget who, but I'm pretty sure it was a luxury marque, which makes sense).

Sadly, I don't (care to) know about what Tesla, et al, use for their systems (it's a function of my age, not my politics). Although now I'm a *little* curious... :biggrin:
 
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Mooseman

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Anyway... Just in the few days between my other post on the Sierra... 3 days ago, I charged it from about 11.89v up to 12.37v in about 30min or so, with the truck's alternator.
Today, it was back down to 11.80v, per the BT monitor, so I trudged out again to give it another charge. Noticed it cranked slower; the monitor showed its cranking voltage to be 7.93v (10.0v or better is considered 'good').
I've got the same thing going on in my Avy. It's an Interstate battery that came with it. And while running, the alternator is pushing out over 15v most of the time. IIRC, it's just 2 or 3 years old. When I stop, voltage just drops to 12v and then goes under just as my Scangauge shuts off.

Something I just saw today was this new video on a de-sulfator. Seems to work in some cases, like in ours:

If it is pooched, I have a new Kirkland FLA that I pulled from the Saab. Been keeping it on a trickle charger. Only problem is that it's a side post and the Avy uses top post in the whacky right rear corner of the engine bay. I'll see if I can relocate it to the left front and use adapters.
 
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Reprise

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the Avy uses top post in the whacky right rear corner of the engine bay.

Amazing. AFAIK, GM has been 100% side post since, what - 1975? And they've stayed with it, even though literally everyone else stuck with conventional top posts.

I was going to say that even the 800s and 900s with dual batteries used side post for the aux battery setup, but I'll look before I put my foot in my mouth and say that definitively.

Oh - and on desulfation - yes, that is recommended, every so often. In fact, a lot of the companies that make replacement battery chargers for RVs & trailers (the stationary / permanent kind) promote a desulfation mode (the mfgr who supplies the OEM stuff doesn't have a desulfation mode, which is another good reason to upgrade; there are others). If you want more info on that, prolly best to PM me -- I don't want to take this thread too far off-topic.

I keep my 2 x 6v GC-2s on float. They've been sitting that way for a long time, now :frown:
 
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DocBrown

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Dec 8, 2011
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I've read that it won't be long until you start seeing 48v electrical systems in autos; with everything that goes into the newer vehicles, the 12v systems are just about at their limits, now.
BMW has been using AGMs in their vehicles for a little while now, and when it's time for a new one, the AGM is a 'required' replacement, IIRC (they have intelligent systems that recognize & optimize charge). I think the replacement battery has to be installed with a high-end scan tool, too (again, BMW, so... )

I'm actually surprised 48 volt systems are not already common. I read a number of years ago that manufacturers were going to start using them.

Amazing. AFAIK, GM has been 100% side post since, what - 1975? And they've stayed with it, even though literally everyone else stuck with conventional top posts.

Both my old 2008 Sierra 1500 and the 2016 Silverado 1500 have top posts. They are an odd design though. The posts are sunk in on the corners so that the cable ends have a long neck a bit like a drop shank for a trailer hitch.
 

Mooseman

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Dec 4, 2011
25,257
Ottawa, ON
Both my old 2008 Sierra 1500 and the 2016 Silverado 1500 have top posts. They are an odd design though. The posts are sunk in on the corners so that the cable ends have a long neck a bit like a drop shank for a trailer hitch.
Ya, same setup on my Avy. Makes it difficult to hook up booster cables. That's why I want to move it to the other front corner. Maybe they put it there to protect it from front end crashes?
 
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HARDTRAILZ

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Nov 18, 2011
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I used a dual post duracell AGM on my 2006 TB since 2013. Best battery I have owned. Been drained more than once from lights left on and done some tough long winch pulls.

Well worth the $130

EDIT: I have a charger from the 1950's/60's that set on start 12 v and plugged in for 2 minutes or typically less will start the AGM if drained. Nothing fancy at all. Never had a charger on it for more than that. Have jump started my truck and used my truck many times with cables on others without issue as well.
Also....Duracell AGM is made by East Penn batteries.
 
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TollKeeper

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Amazing. AFAIK, GM has been 100% side post since, what - 1975? And they've stayed with it, even though literally everyone else stuck with conventional top posts.
I think its kinda hit or miss.. My Buick Rendezvous was standard top post. My sister truck to that, the Aztek, is a regular side post.

Cadillac CTS I rented was top post (in trunk).
Pontiac G8 was top or side, depending on the engine.
 

Jkb242

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May 19, 2019
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In all my posts here, I’ve never received this much feedback. Thanks so much everyone.
it turns out what prompted my original post was after sitting for about an hour or so with the ignition switch not completely at the off position, and watching videos o my phone, I attempted a start no joy dead as a door nail. Got a jump drove home and all seem to be fine, yea, like a dead cell. Fearing that is what I had, I posted the battery question because I was convinced I would need a replacement. After several follow on trips no start issues charging idiot gauge looks normal. So think I just stupidly ran the battery down since the vehicle was not actually off during the hour + video watching.
i knew the OEM battery was not AGM, but COSTCO and others were stocking mostly AGM’s and pretty certain that is what I have since I purchased it at COSTCO. I did not think the charging system on the 06 would play nicely with the AGM charge after discovering the battery type so I have been Leary ever since. I have not been driving the vehicle very much, like everyone else, so it would sit for a week often between starts. I did purchase an inexpensive Autozone charger with a selectable AGM battery setting to prevent the over charge and initial rate control but I suspect the “switch” could just be “eye wash” but have made a current flow duel ring charging to determine.
Unfortunately, when removing the side terminals to wire brush them thinking that could be why it did not start, I think I over tightened the negative 1/2 turn so I could be in trouble sooner than later. The battery seems OK but was thinking I could add some copper stranded wire (14ga) inside the side terminal threads to help tighten the contact. It’s tight but the integrity is compromised. Any suggestions on this. Maybe leave well enough alone not that it’s that well, then pursue a fix?

Thanks to all again!!

negative to w
 
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Mike534x

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Apr 9, 2012
894
I don't think you have much to worry about running an AGM battery, I bought one for my 05 Denali towards the end of October. Its not much time to say for certain, but its been proving itself to be more consistent when it comes to cold starts. Now that our temps (Chicago area) have been hitting the negatives and hovering to a high of 15* F, its so nice to get in and turn the key and hearing it crank over normally and not "slow" like it did with the standard one in there prior. Bought a Duracell one identical to what @HARDTRAILZ has but without the top posts. So far I feel the $110 I spent on it was well worth the investment.


If you're concerned about the integrity of the post for the battery, and it was purchased from Costco. Why not just exchange the battery at Costco for a replacement and put a newer one there?
 

Jkb242

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May 19, 2019
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It was only the charging I was concerned about since the AGM charge rate is slower and intended for vehicles that are equipped to monitor it. This is the second COSTCO battery under warranty. About a year or so after the first one was replaced it failed. I did not want to go through that again.
I have a 2013 “Eqiknocks”, (the Ecotec, engine is not impressive) which was equipped with an AGM battery and contained a sensor on the negative battery cable that monitored charging. At least I’m pretty sure that is it’s purpose. I had to replace under warranty that battery too in almost a year to date. Either the Interstate batteries are junk or I was given the wrong type but two failing a year apart, seems unlikely. I remember being told they did not have the fitment code for mine but had the one for the 6 cyc.model. So I thought that would be fine but something wasn’t right.

I will mention that the factory negative connection really sucks! What a time I had when replacing the batteries on the 2013. The sliding stair case compression fitting once sulfated becomes so bonded, it’s a nightmare to clean and free up. Forget tightening it, once it’s removed. It’s not replaceable separate from the factory negative cable and there isn’t enough room to replace with the old reliable post clamp that works perfectly. Thanks!!
 

Reprise

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You could call that 2013 an "Eeek-it-knocks" (couldn't resist)

If Interstate has Johnson Controls making their batteries, that might explain the early failure. Deka and East Penn seem to put out a better product (but Johnson has the lion's share of FLA manufacturing contracts, by far. They even make AGMs, too (like the Optimas, which 'ain't what they used to be', according to a lot of people who've bought them in the last few years)


AFAIK, all GMT360s use the Grp 34/78 twins -? But you got the one for the 4.2L, and it's apparently not the same battery, so... ?

Yes, your charging system will supply 'higher than optimal' voltage to an AGM.
No, I don't think it's going to cause significant harm (if it did, (a lot of) someone would have documented a need for an 'AGM-specific in-vehicle charging capability', by now). And you can get that via a multi-mode battery charger, if desired.

FYI - Found out while participating in this thread that AGMs supposedly discharge (at least in a latent stage) at 1/10th (!) the rate of FLA batteries. I knew it was slower... but not 90% slower. If true... that's pretty impressive, IMHO.
 

Mike534x

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Apr 9, 2012
894
Interstate is complete garbage in my opinion, especially the loops I spent a year going through just to get mine warrantied. They outright refused because they kept going off what the computer was saying, rather then the fact the battery would lose its charging capacity after sitting overnight if temps outside were 50 deg or under. I had to keep a portable jump pack on me at all times.

I think Hardtrailz mentioned in a thread he got his AGM around 2012/2013 (while searching the forum before getting mine) and only recently replaced it, which I think is a pretty good lifespan for a battery that is not exactly supported correctly by our charging systems on this platform.
 

Mooseman

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Dec 4, 2011
25,257
Ottawa, ON
I have a 2013 “Eqiknocks”, (the Ecotec, engine is not impressive) which was equipped with an AGM battery and contained a sensor on the negative battery cable that monitored charging. At least I’m pretty sure that is it’s purpose.
That is likely the same as on 360's which is the SARVC sensor. It's not designed specifically for the AGM however it monitors battery output and adjusts the charging rate appropriately. My TB has it and will regularly drop the voltage to 12.5V while running when power draw is low.
 

Jkb242

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May 19, 2019
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Thanks everyone, the replies were very helpful. It seems likely that interstate/Johnson Controls has issues not only with quality but but with fitment guides as well. Sad indeed.Costco is a convenient supplier but a middleman in a sea of confusion.
 

TollKeeper

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Dec 3, 2011
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Brighton, CO
And Costco has their batteries supplied by Johnson Controls.
Same with the Wal-Mart/Sams batteries
 

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