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It's battery time

11K views 21 replies 14 participants last post by  frenchsquared 
#1 ·
OK guys, it's time for a new battery. Mine was in the car when I bought it two years ago. It looked like new but I guess it wasn't. It is an AC-Delco group 75 and the "branded" date code can't be read because of a poor stamp job.

The old Delco will only hold 12.3 volts. Charged up it is 12.8 but drops to 12.5 within a day, then settles at 12.3 even with it removed from the car. I thought my starter was getting tired but it's the battery instead.

My question is type of battery. I wanted a AGM but nobody makes one in a group75 size. I also checked on an Oddsey battery but at $289 I don't think I can afford that.An Optma is a little cheaper but the battery shop that sells them advised aganist buying one stating that lately they have had lots of trouble with them.

Will a group 78 fit? I have measured and it seems it might fit but it will be tight. Should I just stick with a Delco Professional Gold? I can get one of those for $130, but a AGM in a 78 size is only $150.

Wadda say guys? Anybody had the same problems?
 
#2 ·
Just my humble opinion, but batteries are relatively cheap. I see no reason to spend a ton of money on one. You should be able to get a decent brand name battery for $100 or less and it wont make your car any slower than the $289 battery. It might not last as long, but at less than half the price, you can replace it every two years and still come out ahead. I have had more than my share of battery troubles, and it seems the "quality" (price) of the battery doesn't make any difference. They all tend to be reliable for 2-3 years.
 
#3 ·
...I most often put ACDelco's in my vehicles but actually
any good grade battery will do, brands really mean nothing
anymore they all claim the same thing, my only requirement
is that I have a quality alternator installed, I think that is
more important than battery hype.....my $.02
 
#4 ·
I happen to sell Interstate at my shop and I can say that in the 11 years I've been here, I have seen one battery go bad before the warranty date. It had a bad cell and was replaced free of charge after two years. The MT-75 interstate is a great battery for the vette. I had one in mine before i traded it in. It was in there the nine years I owned it. Tended every year from november to april with no problems. That can be bought for around $100.00.

I have nothing against delcos either. No problems with them in the past. I do recommend you stay away from a walmart battery or advance auto parts silver brand. they are junk. Even Die Hards don't seem to last like they used to. I also don't see a need for an Optima unless you are running amps and speakers. Then that would help a bit.
 
#8 ·
I happen to sell Interstate at my shop and I can say that in the 11 years I've been here, I have seen one battery go bad before the warranty date. It had a bad cell and was replaced free of charge after two years. The MT-75 interstate is a great battery for the vette. I had one in mine before i traded it in. It was in there the nine years I owned it. Tended every year from november to april with no problems. That can be bought for around $100.00.

I have nothing against delcos either. No problems with them in the past. I do recommend you stay away from a walmart battery or advance auto parts silver brand. they are junk. Even Die Hards don't seem to last like they used to. I also don't see a need for an Optima unless you are running amps and speakers. Then that would help a bit.
Then it must be about time for my WalMart EverStart MAXX 78S battery to die. Purchased 3/16/2010...
 
#5 ·
After purchasing my car in 2005, the original AC battery lasted 1 year. Installed an Optima Red Top. It lasted 1 year.
Tired of spending money on batteries, I made a trip tp Pep Boys and bought a Bosche battery. It's been in the car for 5+ years now, and still performs like new. I have since bought these batteries for my other vehicles and so far have a zero failure rate.
 
#6 · (Edited)
The C5 has a inherit parasitic battery draw and requires a specific 120 minimum reserve capacity and voltage as discussed in Paul Koerners seminar videos on the C5 column lock issues.

The last time I asked Optima technical service, they still do not manufacture a battery specific for the C5 needs.

Choose the battery of your choice, but atleast educate yourself on the C5's electrical needs .....so that you save yourself additional troubles. :cheers:
Part 1
http://vettetube.com/view_video.php?viewkey=65c9da25f49408d959ca

Part 2
http://vettetube.com/view_video.php?viewkey=572f183c1a84ce5276e9
 
#7 ·
I have had two Delcos that died.

Then installed a Red Top and it did not fail, but was suspect in intermittent electrical issues (never failed to start the car).

Replaced with another Red Top after 2 years... it too was suspect at not delivering full power at all times - also never failed to "start" the car.

I replaced it with a Die Hard Platinum P4 34/78DT CCA 880 RC 135 which EXCEEDS the newer C5 requirements. Installed it last September and have had steady voltage for the longest period so far.

With batteries anymore I think it is luck-of-the-draw. The Die Hard was the most expensive battery I have ever purchased, but so far no complaints. Not sure I really trust any battery over 2-3 years - even though I never had a Red Top fail to start the car.
 
#9 ·
A group 78 will fit perfectly. I just installed an Optima Red group 78 which has increased CA and CCA over the 75 AND sufficiant RC; and to me, most importantly, it's sealed.

The C5's unfortunately have a major wiring harness and electronics directly under the battery tray and I heard too many stories of leaking battery acid causing major and costly damage.

My CTEK battery maintainer works perfectly with it too. ;)
 
#10 ·
#13 ·
When it was time to replace mine(cracked terminal) I wanted an American made product. There is a fellow near my home that operates a shop that sells only batteries and related items. He sold me a Deka battery and I have had no problems for several years now. If you are interested in originality ,a battery is an easy change.
 
#14 · (Edited)
My 99 C5 had some goofy electrical issues when I bought it. The headlights would come on...by themselves...during the day. There was some other weird crap with the HUD blurring as well.

When I got the A/C fixed my electrical guy said the battery was the wrong type, and didn't have the right specs for the C5. He put an AC Delco in (even though he's an Interstate dealer) it, no issues ever since.

I found it interesting he went with the Delco over the Interstate. He had the car for 10 days, so he had plenty of time to get an Interstate if he thought it was the right battery.

Go figure.
 
#16 ·
My 99 C5 had some goofy electrical issues when I bought it. The headlights would come on...by themselves...during the day. There was some other weird crap with the HUD blurring as well.

When I got the A/C fixed my electrical guy said the battery was the wrong type, and didn't have the right specs for the C5. He put an AC Delco in (even though he's an Interstate dealer) it, no issues ever since.

I found it interested he went with the Delco over the Interstate. He had the car for 10 days, so he had plenty of time to get an Interstate if he thought it was the right battery.

Go figure.
Sounds like you found a guy you can trust, who did his research and who was more interested in correcting the problem than just selling you a battery.
Bravo......:thumbsup:......those guys are few and far between.
 
#18 ·
As I'm still the original owner of my 03Z (currently 21K miles) which left the dealer new with 0.4 miles and a AC Delco Professional 120 RC battery, always maintained with a "Battery Tender", I have gone through two Column Lock bypasses untill finally disabled and currently working on only my second battery...........and second battery tender.

Figures, :thud: it would be just my luck it only occurs to Torch Red Z's :laughing:
 
#20 ·
I am very happy with my optima... It is 5 years old.
It goes dead every winter, since I don't seem to put it on a tender. Works fine every spring.
Oldest one is 7 about years old.

Fit just fine in my 2000.
No weird issues...

I will only buy Optima and currently have about 3 of them. Sold one recently.

Before I get yelled at, I will put the vette on a tender. Battery was in a 78 Camaro.
I only used the car to race and did not care. It was in storage in a place without electricity.
 
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