JerryU

According to the 2014 Service Manual and most other battery charts 12.45 volts is only 65% charged at 75F. To be fully charged it must be a minimum of 12.75 volts. AGM's are usually even higher.

Since I have had this problem since new I asked forum folks to post their voltage. Most reported 12.8 to 12.9 volts. I check the wife's new SUV and it is 12.9 volts. I believe mine had a weak cell(s.) I'll be checking to be sure.

FWIW, brought my best digital Craftsman multimeter to the Battery Store and checked several batteries on their shelf against their calibrated Fluke meter. It was within 0.01 volts.

JerryU

No, to get a September 2013 built C7 I ordered from the only dealer who would take an early order even before there was any pricing, Hendrick in Cary NC! Had a contract based on MSRP that nether knew what it would be! In fact I was #9 on their list. Would check with the salesman from time to time to be sure I was still #9! One time he said, "You'll be #9 unless Jeff Gordon decides he wants one, then you'll be number 10!"

I got mine only a few weeks after Rick Hendrick got the first C7 coupe built. He paid $1,100,000! It was at a Barrett Jackson Charity Auction. Great folks to buy from! Picked up my car the day after it came off the truck.

Twisted Swifter

Bookmarked this bad-boy.

Nice work JerryU! Thank you for sharing.

7LitreC5

Thanks for posting this info and for putting together the pdf.

50th year

Wow
What an ordeal just to change a battery. Thanks for the write up.

Patches

Thanks for the PDF, Jerry - it was helpful to me in preparing and actually doing my battery swap this week. I had bought a replacement battery several weeks ago for my '14 C7, anticipating the demise of the original battery still in it. I noticed slight hesitation in some recent starts so figured I should have a new battery ready to go. I bought the same battery you did and had it on the bench charging for when I was ready. I ordered a battery carrier at Autozone Sunday and, when I stopped to pick it up Tuesday, the starter hesitated when I went to leave the store to go home so figured I wouldn't wait any longer.

Battery - handles are very helpful in transport and installation.


The carrier I picked up - made removal easier.


The swap was pretty easy, although, I agree access and removal are a bit clumsy but I had no problem doing the swap. I removed most of the rear panels to ensure I didn't crack the main deck cover - I'd done it before so it came out quickly.

What I found was a positive terminal that was starting to corrode. My C7 is my dd so I've never had to charge the battery and haven't needed to remove it. The corrosion did not show until I removed the positive cable card and terminal.


New battery works perfectly and only one or two settings changed as I used a 9V battery device in the lighter socket to retain memory settings while the battery was out, although I do need to re-index the windows.

JerryU

Thanks.

That battery carrier is much better that the simple post strap I bought. With the terminals on the end, the strap did not pull it straight up. On the first try it also slipped when I had it about 3 inches up! Finally lifted out of the "hole" and set it on the hatch floor. Lifted with two hands over the spoiler. Would not trust the strap to hold lifting it over the spoiler!

Anyone who thinks they will lift out with their hands, think again! No room for hands or fingers.

traronf

Does the plastic cover just pull off the positive terminal, or is their a tab that needs to be depressed to remove it?

JerryU

To get the Power Board off the positive terminal, first discounted the negative terminal, then unbolt the power buss bar from the bar going to the car, then to remove the power board (with fuses) there are two clips to release.

traronf

Thanks Jerry, the plastic cover does it just pop off or are there clips holding it that need to be released?

Nordic_Samurai

It's insane what it requires to change a car battery nowadays...

jtranger

Do you have a brand name and part number for the battery carrier? Thanks

Foosh

Amazon has many, and several very similar to the one above. They're very cheap. The one above is branded "OEM Tools" and is on page 2 of the link below.

rmorin1249

Does anyone sell an AGM battery that has a longer replacement time than the 36 months provided with the DieHard AGM? Our local Sears store closed and the battery is not shippable. Thanks.

Added: I am going to try KMart.

Foosh

Not that I've found. The AC/Delco AGM version has about the same specs, price and warranty.

There are conventional wet batteries w/ longer warranties, but my understanding is that AGMs do last longer. I don't know why their warranties don't reflect that.

Skid Row Joe

THX, Foosh!

I'm definitely going to need one then too. I could actually use it for my 2002 7.3 liter PSD engine compartment battery.

TEXHAWK0

I have a friend with three Corvettes, all with AGM batteries, and he recently just had to replace all of them in a short period of time. According to him, the manufacturer has them designed where they all last about 3 years.

I went with the ACDelco Professional gold series battery with 42 month free replacement. I have taken one to the parts house that was over 3 years old and just told them it was not holding a full charge and they replaced it free, no questions asked.
When I changed my battery I found it was easier to lift it over the rear fender instead of trying to lift it over the spoiler, and was able to do it without a carrier. I also remove the whole side panel to get it out of the way, and completely removed the box on top of the battery.


Say something about this photo

JerryU

It just pops off.

JerryU

I'm reminded of a comment made by the Plant Manager at Johnson Controls battery plant in town when we had a tour. They assembled batteries and have long wide tubs of water where ~100+ batters sit almost up to the top as they are cooled while being charged. Then they go down an assembly line where there were over 20 brand labels being applied by workers!

They operate on a "just in time" basis with their customers. If AutoZone, Advanced Auto sells a particular model or Sears who was selling a Diehard, they put that label on and deliver a replacement! Some brands had different color case that started assembly in that colored case. The internals were the same.

Someone in our group asked what was different and he said "Often just the warranty! Some companies give a longer warranty and charge more!

Of interest, Johnson Controls bought Optima some years ago. They are not made at this plant but were in the packaging area and are assembled with the batteries they make for delivery to their customers. Battery plants are located around the US as shipping is a significant cost. Just who is selling a particular model is regional dependent. I saw the Diehard AGM I bought for the C7 with a different label at AutoZone.

NSC5

Jerry,

Thanks for documenting your experience.

A quick general question on AGM batteries: any concerns about using one where they weren't originally specified? I have never used one but I am getting ready to order a new GMC Sierra diesel pickup and while looking through the supplemental manual for the diesel engine, which also covers the little diesel used in GM's midsize trucks, I saw that the midsize (Canyon, Colorado) with the small diesel come with an AGM battery and the manual warns not to use a regular battery charger with them since it should be limited to a maximum of 14.8 volts during the charge cycle. Any concerns about the standard vehicle electrical system allowing excessive charging voltage?