Time for a new Battery
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Product ID: MT7-78
Cranking Amps: 1000
Cold Cranking Amps: 800
ReserveCapacity-25: 125.00
It also appears that most Interstate batteries (including the AGM) are made by Johnson Controls at this time, but not all are.
Good luck... GUSTO
Last edited by GUSTO14; Jun 24, 2016 at 11:28 AM.
Melting Slicks
Joined: Jun 2013
Posts: 3,473
Likes: 691
From: West Virginia
Been running a Sears Platinum (78) for many years now. On occasion where the car has been sitting for a long time (snow on ground, etc.), it starts right up, no issues. Never needed a tender. Can't remember when I bought it, but probably 2008, so I definitely have no complaints.
Last edited by jackthelad; Jun 24, 2016 at 02:07 PM.
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Team Owner
Joined: Mar 1999
Posts: 22,025
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From: At the beach in little Rhody
Went to pick up the new battery. Bottom was a bit wider than the Exide but it still fit. On the Advance Auto web site, they show the AGM as being grey in color, same as the GM battery shown above in Gusto's post. However, the battery was black and looks a tad different in shape as well. I asked about this and was told that all the newer batteries have been black and the older ones are grey. The date of manufacture for mine is February 2016, most other stores had them much older. Had to drive a bit farther to get it but we had a nice lunch in the area so all is well. It is now on the CTEK being charged and should be good to go after that.
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Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
Didn't see any battery with an RC value that high, and the original size group of 75 is even lower. Not sure where that requirement comes from since the one GM sells specific for the car doesn't even come close.
Le Mans Master
Joined: Sep 2001
Posts: 5,022
Likes: 1
From: TEXAS
Been running a Sears Platinum (78) for many years now. On occasion where the car has been sitting for a long time (snow on ground, etc.), it starts right up, no issues. Never needed a tender. Can't remember when I bought it, but probably 2008, so I definitely have no complaints.
http://www.odysseybattery.com/extrem...ery_specs.aspx
Le Mans Master
Joined: Sep 2001
Posts: 5,022
Likes: 1
From: TEXAS
It's my understanding that the lower RC (lower than 120) can cause problems due the C5's parasitic drain and the lower RC messes with the column lock mechanism.
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Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
I disengaged my power lock with a bypass kit in 2001, first modification to the car. Never been an issue since. Not too worried on the parasitic drain since if I don't drive the car for a week or so I plug in the CTEK.
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Melting Slicks
Joined: Jun 2013
Posts: 3,473
Likes: 691
From: West Virginia
That's the Sears Platinum 34/78DT which I have and was mentioned in post #2. But, Sears does not show it on their website. Someone posted that they thought it was made by Oddessy batteries. That's possible because the Sears battery's specs of 850 CCA, 130 RC is the same as the Oddessy battery #34/78 PC1500 as seen below.
http://www.odysseybattery.com/extrem...ery_specs.aspx
http://www.odysseybattery.com/extrem...ery_specs.aspx
It seems that it is an unwritten rule of marketing that when you really like a product and want to buy another one, it has either been modified, replaced with a cheaper version, discontinued or the firm has been bought out, gone bust, etc.
And on top of that my local Sears Auto Center, where I bought the thing has been shutdown - and they used to be very busy, with a lot of tire sales for starters.
They really are out to get us all you know........
Last edited by jackthelad; Jun 24, 2016 at 04:43 PM.
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Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
Melting Slicks
Joined: Jul 2014
Posts: 2,782
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From: The Lowcountry South Carolina
Well, my car almost didn't start a few times today and has been slower turning over lately. Battery is 10 years old so I can't complain.
What has anyone found as a good battery noting I am running higher compression than stock?
Will a 78 size fit in the C5? Right now I have the stock battery size, although it has served me well.
What has anyone found as a good battery noting I am running higher compression than stock?
Will a 78 size fit in the C5? Right now I have the stock battery size, although it has served me well.
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
Regardless of the different brands, there are only just a few makers of all brands of batteries, with most being made by Johnson Controls. I myself am running an Optima Red Top, size 78. It fits in perfectly. My previous battery was also the same, it lasted 15 years with no problems.
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Team Owner
Joined: Mar 1999
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From: At the beach in little Rhody
Well, its installed, charged and the car starts unbelievably. I think the old battery, although it still started the car, just wasn't putting out the amps. Now it turns over great when you hit the key, hot or cold. Can't complain though, ten years was a long life for a car battery
I suppose tires are next, since those are going by date and not by tread wear.
I suppose tires are next, since those are going by date and not by tread wear.
Drifting
Joined: Jul 2015
Posts: 1,844
Likes: 375
From: San Jose, CA
I ordered what looks like the new ACdelco version - ACDelco 78AGM Professional AGM Automotive BCI Group 78 Battery - $155 plus tax. Will let you guys know how it goes.
Imagine my surprise when I was scrolling through the gauges with the engine off, and it told me that the battery was at 11.8 volts. Never fails to start, but... I should really check with my multimeter; regardless, a new battery is clearly in order.
Imagine my surprise when I was scrolling through the gauges with the engine off, and it told me that the battery was at 11.8 volts. Never fails to start, but... I should really check with my multimeter; regardless, a new battery is clearly in order.
Thread Starter
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Mine was sluggish first turning over, but the car starts so well it still was pretty good. But last week on a hot day I thought I was going to get stuck in a parking lot when I came out to start the car, so out with the old in with the new. Wasn't until I did this that I realized just how bad the old one had gotten.
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Mine was sluggish first turning over, but the car starts so well it still was pretty good. But last week on a hot day I thought I was going to get stuck in a parking lot when I came out to start the car, so out with the old in with the new. Wasn't until I did this that I realized just how bad the old one had gotten.
Bottom line is that the C5 is particularly sensitive to low voltage irregularities.
Good luck... GUSTO