Replacing AC Delco battery
Thread Starter
Racer
Joined: Dec 2004
Posts: 336
Likes: 3
Replacing AC Delco battery
My 2003 coupe battery just died yesterday on a cruise with the club I belong to. I have always used a battery tender and the car has always started fine. When the battery was pulled it was swollen. Had to buy a group 75 battery at Sears. This new one is not an AGM style. Where is the best place to find matting to place under the new one to absorb any leaking acid that could occur.
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Don't worry too much
The original AC Delcos that leaked are all gone now. The latest batteries are redesigned and shouldn't cause a problem.
If youre really worried you can get them online
The original AC Delcos that leaked are all gone now. The latest batteries are redesigned and shouldn't cause a problem.
If youre really worried you can get them online
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
The reason we're all paranoid about leaks here is the original AC Delcos had a design fault. If you over torque'd the battery leads the case could crack and leak on the PCM. It caused many problems with the computers and the HVAC.
The latest crop of batteries don't have that issue so the chances of a leak are reduced.
The latest crop of batteries don't have that issue so the chances of a leak are reduced.
Melting Slicks
Joined: May 2003
Posts: 3,312
Likes: 648
From: Utah's Dixie UT
St. Jude Donor '11 thru '26
The battery just died in my '03, it had been replaced twice, under warranty, within a few months of my buying the car. When I pulled it out I saw that it was a 78 series not the 75 that is listed as OE. I got a Delco 7 yr for replacement but stayed with the 78.
Win
Win
Melting Slicks
Joined: Jul 2006
Posts: 2,332
Likes: 31
From: Silver Spring MD
My 98 uses a 78 think they are a little heftier than a 75
Had the acid leak and had to redo the vacuum hoses and check valve.
Good idea to remove the battery tray and flush with a boric acid bath mixed up in at least a gallon of water. Let dry then paint any surfaces the acid got to.
BIGHANK
Thread Starter
Racer
Joined: Dec 2004
Posts: 336
Likes: 3
Did not find any evidence of leaking acid or any damage under the old battery. I was just concerned that I was not using an AGM style battery that came with the car. I am aware that others have had issues with non-agm batteries and was just trying to get info on ways to protect my car from future issues with the Sears replacement.
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Melting Slicks
Joined: Oct 2007
Posts: 2,798
Likes: 8
From: It's true money can't buy happiness, but it is more comfortable crying in a Corvette than on a bicyc
St. Jude Donor '13
Mine was a Group 78. I went with a Red Top Optima even with all the hard luck stories out there. I had minor acid damage from the Platinum battery that Advance sells. Half a box of baking soda neutralized the acid then rinsed it out with the garden hose.
Race Director
Joined: Dec 2000
Posts: 19,304
Likes: 85
From: San Diego CA
Did not find any evidence of leaking acid or any damage under the old battery. I was just concerned that I was not using an AGM style battery that came with the car. I am aware that others have had issues with non-agm batteries and was just trying to get info on ways to protect my car from future issues with the Sears replacement.
You can buy a mat from Ecklers but in all likelyhood, you will never need it.
Melting Slicks
Joined: Mar 2003
Posts: 2,512
Likes: 49
From: Franklin IN
Me too!
I am currently cleaning up a battery acid spill from the P.O.. I removed the battery battery, base plate, PCM, Tach module. All had dry acid on them. I was told by a GM world class tech if left it will eat it way through the case of the PCM, cables, and vacuumm lines (for the AC). He suggested I use the spray foam battery cleaner. Clean it all and repaint the frame where the acid ate the paint off. I have a Wheelhorse Lawn Tractor. The battery sits down in a case that has a plastic tube that drains off any potential acid spills why in the hell GM didn't think of that is beyond me.
Instructor
Joined: May 2010
Posts: 117
Likes: 2
From: Providence RI
I replaced mine with ACDelco Part Number: 78-6YR. This is a 6 year battery with 700 cca and costs lest than Part Number: ACD78-60 which is a 5 year battery with only 670 cca. Sometimes, just can't figure GM's pricing out? 
Melting Slicks
Joined: May 2003
Posts: 3,312
Likes: 648
From: Utah's Dixie UT
St. Jude Donor '11 thru '26
I had no sign of acid leak when I pulled the battery, I had checked when the OE was replaced and the failure was not due to leaking. Got lucky, I think.
Win
Win
4th Gear
Joined: Mar 2007
Posts: 4
Likes: 0
From: Gassville AR
Another good battery p/n is 78-7yr which is 800cca and costs very little more.
