Welcome to the Corvette Forums at the Corvette Action Center!

Question: C5 battery types??

I've stuck with the Delco Professional OE battery and NOT had a single problem since day one...

Your 2004 has the benefit of top terminals. My 98 has side terminals which are prone to leaking. I have a receipt for about 3 grand in replacing everything that a leaky Delco destroyed.

I'm likely to go back to a delco though and I'll keep an eye on it or pony up for an Odyssey, Apex batteries has the one for C5's on sale for approx. 250 shipped.

Optima wants me to take the battery back for another test overnight. What a pain in the ass. I'd even be willing to take the car up there and swap another battery in for a test to see if that works but you would think their batteries are liquid gold because they won't let them out of the store.

Autozone was willing to swap it out after testing it until I showed them the receipt was for Advance.

Another option I have is to buy top to side post adapters and trying a battery from one of my other cars. I have not decided yet. What I have been doing is leaving a battery tender on it each night and carrying a jumper box in the trunk just in case.
 
Battery

:wI plan to take the vette on a long trip in the spring and I think my battery should be replaced. I looking at the different types, I noticed that the c5's use different types.:confused

MY1997-2000 =#78 (mine)
MY2001,02,03 = #75
MY2004 = #86

The one I need seems to be the most powerful and slightly larger.
I didnt think there was any mod to the car/battery box etc. over the years.
Why?? and is there an advantage to swapping to another group type??


I bought a new Duracell battery in the appropriate size and CCAs from Sam's Club this past spring -- $99 plus tax plus recycle charge and out the door for about $120. Maintenance free so no chance of drips down into the electrics below the tray. I keep in on a Battery Tender Jr. when not in use. It has plenty of juice for crisp start-ups and if it fails in 3-4 years I'll buy another.

It doesn't make sense to drop $160-$200+ to get maybe another year out of a battery. This way I'm always driving with a relatively new battery.

Just my 2 cents.

Enjoy your ride.

Bill :w
 
Adding to this.

HI there,
The actual fact is that ALL c5 to 2003 should have a 78 class battery rated at least for 550 CCA.

2004 is an 86 class as listed.

c5 must have at least 500 cold cranking amps for correct electrical function when starting the car.

Make sure those battery terminals are torqued to 11 ft lbs.

Allthebest, c45

From what the Video of the Column Lock Debunked Sticky from the GM Tech here says to run the AC / Delco with 78-6YR Battery. It is the Reserve Capacity or "RC" needing to be at 120 so that it will be able to have enough to keep the column lock problem from happening.
 
Everyone needs to know how important reserve capacity is. It is critical for the C5 which has so much electronic crap in it. Here is a video that discusses that and the GM specs for it. It will tell you all you need to know in the first few minutes of video 1. It later goes on to discuss why 99.9 % of all CL issues are battery related. While the 97-03 takes a 78 and the 04 takes a 86, they both require a 120 RC.

VetteTube - Corvette Video: World Class Technician, Paul Koerner, discusses C5 Column Lock-


VetteTube - Corvette Video: Paul debunks the Column lock issue



PS: I still put in an LMC5 to prevent battery issues from causing a problem and to prevent that .1% from affecting me.
 
Last edited:
I watched both videos in their entirety and have a few thoughts.


  • AGM batteries definitely are lead-acid batteries and definitely are not “gel cell” batteries, as was suggested in the first video. That is an important distinction, because many battery chargers have gel-specific charger settings that may not fully-charge non-gel batteries and could damage them over time.
  • In the second video, the speaker opens up by referring to Optima batteries generically as “deep-cycle gel cells.” This is false, as not all of our batteries are designed for deep-cycle use and none of them are gel cell batteries.
  • A 30-month replacement warranty is definitely not the “best in the industry” now and it wasn't when that video was filmed either.
  • I would agree that batteries should be load-tested annually as best practice, although that rarely happens.
  • Having an auto parts store test a battery is depicted as being unreliable and it is suggested you may end up being sold a battery you don't need. The same thing can happen at a dealership. Regardless of where a consumer goes to have their battery tested, if they make sure they have at least attempted to fully-charge it (at least 12.6 volts) before having it tested, there is a good chance they will get an accurate test.
  • The speaker indicates two options for battery testers- a $600 dealer unit or a $90 solar unit. Again, either unit may not provide accurate test results if the battery is deeply-discharged. After talking about those two options, he only shows the voltage measured by the two units. Anyone can do that with a $10 voltmeter. Later in the video, he talks about measuring CCAs with the $90 unit, but again, most auto parts stores can perform the same test and many will do it for free.
  • The suggestion that batteries with more reserve capacity are needed for newer Corvettes is basically indicating that there is a leak in the electrical fuel system of newer Corvettes, so a bigger electrical fuel tank (battery) is needed. That is one way to address the issue (regularly using a quality battery maintenance device being another) but it may not be a permanent solution. What is never mentioned in this presentation is that when a battery with more reserve capacity is deeply-discharged, the vehicle's alternator will have to work that much harder in an attempt to fully-recharge that battery (which most end up not doing). Relying on the alternator to do the work of a battery charger can result in a cycle of dead batteries and jump-starts, until either the battery or alternator fails.
  • Removing the negative battery cable on vehicles that will be sitting for extended periods of time is also mentioned as an option. However, no mention is made of making sure the battery is fully-charged before the cable is removed. Disconnecting the cable may prevent the battery from being discharged further by the vehicle (beyond the battery's normal self-discharge rate), but if the battery is already discharged to some degree when the cable is removed, the battery may still be sulfating while in storage.
  • The “normal voltage” of 12.28 volts shown after four weeks of storage is about 40% discharged for most batteries. Once that battery drops below 12.4 volts, sulfation is forming in the battery plates, which diminishes both capacity and lifespan.
  • For whatever reason, GM has been reluctant to follow the lead of many other high-performance automakers, who include battery maintainers with new vehicle purchases, instead opting to recommend a bigger battery as a solution. The same issues can arise with batteries with more reserve capacity, it will just take longer to happen.
  • Keep your battery fully-charged whenever possible and you will maximize battery performance and lifespan and minimize the chance of these voltage-related issues plaguing your car

Jim McIlvaine
eCare Manager, OPTIMA Batteries
OPTIMA® Batteries (optimabatteries) on Pinterest
 
I watched both videos in their entirety and have a few thoughts.


  • AGM batteries definitely are lead-acid batteries and definitely are not “gel cell” batteries, as was suggested in the first video. That is an important distinction, because many battery chargers have gel-specific charger settings that may not fully-charge non-gel batteries and could damage them over time.
  • In the second video, the speaker opens up by referring to Optima batteries generically as “deep-cycle gel cells.” This is false, as not all of our batteries are designed for deep-cycle use and none of them are gel cell batteries.
  • A 30-month replacement warranty is definitely not the “best in the industry” now and it wasn't when that video was filmed either.
  • I would agree that batteries should be load-tested annually as best practice, although that rarely happens.
  • Having an auto parts store test a battery is depicted as being unreliable and it is suggested you may end up being sold a battery you don't need. The same thing can happen at a dealership. Regardless of where a consumer goes to have their battery tested, if they make sure they have at least attempted to fully-charge it (at least 12.6 volts) before having it tested, there is a good chance they will get an accurate test.
  • The speaker indicates two options for battery testers- a $600 dealer unit or a $90 solar unit. Again, either unit may not provide accurate test results if the battery is deeply-discharged. After talking about those two options, he only shows the voltage measured by the two units. Anyone can do that with a $10 voltmeter. Later in the video, he talks about measuring CCAs with the $90 unit, but again, most auto parts stores can perform the same test and many will do it for free.
  • The suggestion that batteries with more reserve capacity are needed for newer Corvettes is basically indicating that there is a leak in the electrical fuel system of newer Corvettes, so a bigger electrical fuel tank (battery) is needed. That is one way to address the issue (regularly using a quality battery maintenance device being another) but it may not be a permanent solution. What is never mentioned in this presentation is that when a battery with more reserve capacity is deeply-discharged, the vehicle's alternator will have to work that much harder in an attempt to fully-recharge that battery (which most end up not doing). Relying on the alternator to do the work of a battery charger can result in a cycle of dead batteries and jump-starts, until either the battery or alternator fails.
  • Removing the negative battery cable on vehicles that will be sitting for extended periods of time is also mentioned as an option. However, no mention is made of making sure the battery is fully-charged before the cable is removed. Disconnecting the cable may prevent the battery from being discharged further by the vehicle (beyond the battery's normal self-discharge rate), but if the battery is already discharged to some degree when the cable is removed, the battery may still be sulfating while in storage.
  • The “normal voltage” of 12.28 volts shown after four weeks of storage is about 40% discharged for most batteries. Once that battery drops below 12.4 volts, sulfation is forming in the battery plates, which diminishes both capacity and lifespan.
  • For whatever reason, GM has been reluctant to follow the lead of many other high-performance automakers, who include battery maintainers with new vehicle purchases, instead opting to recommend a bigger battery as a solution. The same issues can arise with batteries with more reserve capacity, it will just take longer to happen.
  • Keep your battery fully-charged whenever possible and you will maximize battery performance and lifespan and minimize the chance of these voltage-related issues plaguing your car

Jim McIlvaine
eCare Manager, OPTIMA Batteries
OPTIMA® Batteries (optimabatteries) on Pinterest

GM offers a battery protection package (i.e. a battery charger) on the new Corvettes, and has for years, as an option. Not everyone stores their cars which is why it is an option.

Optima still recommends a battery for the C5 that doesn't meet manufacturer spec. That is likely my issue. Through startup the key is there is a big load and for a long time. The crappy battery I have is fried likely because of the extreme draw through startup. The car starts but the voltage is very low afterwards and it has to rebuild its way back to normal. This is coming directly off charge. Either way the car is haywire and C4C5 specialist is correct in that the battery should have been load tested. Take it to one place they say to change it out, another says not to. This is exactly what he is saying... the voltage testers vary from place to place.

In regards to the warranty comment above... One can buy a GM battery and actually get it replaced within 30 months or one can buy an Optima and get blown off within 36 months. Based on my experience the GM warranty is in fact best in the industry because it's an actual warranty VS. a line of Bull Crap.
 
Vettelt193, you previously indicated you took your battery to a retailer who did not originally sell it to you for warranty service. Warranty service is generally handled by the original retailer. I understand your frustration, but I did request and never did receive your contact information or that of your original retailer, which limits my ability to assist you.

Once a vehicle starts, how are you able to distinguish battery voltage from alternator output? What are the OE specifications for your battery and which one(s) does your Optima fail to meet?

If GM's logic is that an item should only be standard equipment if everyone uses it, then why did so many GM vehicles end up with OnStar hardware installed? I've read the comments from Corvette owners who are outraged with the thought of having to plug their cars in, especially considering the price they paid for them. Some have speculated that battery chargers are not standard equipment for some cars, because manufacturers don't want to send the message to consumers who just paid a bunch of money for a car, that they should also make a habit of plugging it in, especially when their kid's new econobox doesn't need similar care.


Jim McIlvaine
eCare Manager, OPTIMA Batteries
OPTIMA® Batteries (optimabatteries) on Pinterest
 
Last edited:
Clarification

Hi there,

In the interest of clarification, lets be clear on a few points.

#1, 78PS from ACDelco is the latest battery recommendation for 1997-2003 Corvette. This has the 120 RC that is so critical in these vehicles.

#2, 86PS is a top post directly applied to the 2004 Corvette. This reserve capacity is only 110. Now, it is important to know that changes in certain systems in 2004 made the slightly reduced reserve capacity ok for 2004 ONLY.

#3, all vehicles drain their batteries. No matter what, no matter what manufacturer. In order to retain memory of radio, clocks, engine control module and other systems, the battery is used while the vehicle is off. In the C5 body style, this draw of electricity is maxed out at 30 milliamps. C6 and C7, it is 20 milliamps maximum.

GM dictates that if ANY vehicle is left without usage for more than 21 days, it have its battery disconnected.

Allthebest, Paul
 
Hi there,

In the interest of clarification, lets be clear on a few points.

#1, 78PS from ACDelco is the latest battery recommendation for 1997-2003 Corvette. This has the 120 RC that is so critical in these vehicles.

#2, 86PS is a top post directly applied to the 2004 Corvette. This reserve capacity is only 110. Now, it is important to know that changes in certain systems in 2004 made the slightly reduced reserve capacity ok for 2004 ONLY.

#3, all vehicles drain their batteries. No matter what, no matter what manufacturer. In order to retain memory of radio, clocks, engine control module and other systems, the battery is used while the vehicle is off. In the C5 body style, this draw of electricity is maxed out at 30 milliamps. C6 and C7, it is 20 milliamps maximum.

GM dictates that if ANY vehicle is left without usage for more than 21 days, it have its battery disconnected.

Allthebest, Paul
I talked with a couple smart guys at GM a few years back and they said exactly what you posted .BUT sadly 47.6% won't buy it ,especially the last line :D

I appreciate ya Paul ,always good info.
 
I watched both videos in their entirety and have a few thoughts.


  • AGM batteries definitely are lead-acid batteries and definitely are not “gel cell” batteries, as was suggested in the first video. That is an important distinction, because many battery chargers have gel-specific charger settings that may not fully-charge non-gel batteries and could damage them over time.
  • Actually, the AGM battery in Corvette was a GEL CELL, due to the fact of the design, using fiberglass absorbed gel acid mat that separated the plates. What did you think I was discussing?



  • In the second video, the speaker opens up by referring to Optima batteries generically as “deep-cycle gel cells.” This is false, as not all of our batteries are designed for deep-cycle use and none of them are gel cell batteries.

Clarify your design then, as I was not blast on your product and if I was wrong, I will say I was wrong.

A 30-month replacement warranty is definitely not the “best in the industry” now and it wasn't when that video was filmed either.

What is your warranty without prorating?


  • I would agree that batteries should be load-tested annually as best practice, although that rarely happens.


  • Having an auto parts store test a battery is depicted as being unreliable and it is suggested you may end up being sold a battery you don't need. The same thing can happen at a dealership. Regardless of where a consumer goes to have their battery tested, if they make sure they have at least attempted to fully-charge it (at least 12.6 volts) before having it tested, there is a good chance they will get an accurate test.
  • The speaker indicates two options for battery testers- a $600 dealer unit or a $90 solar unit. Again, either unit may not provide accurate test results if the battery is deeply-discharged. After talking about those two options, he only shows the voltage measured by the two units. Anyone can do that with a $10 voltmeter. Later in the video, he talks about measuring CCAs with the $90 unit, but again, most auto parts stores can perform the same test and many will do it for free.

Once again, I am not speaking for the aftermarket, I am speaking from a GM dealership point of view to assist the owners. Actually, the GM tested can accurately test inductance and also soundness of the battery down to 10 volts.

The suggestion that batteries with more reserve capacity are needed for newer Corvettes is basically indicating that there is a leak in the electrical fuel system of newer Corvettes, so a bigger electrical fuel tank (battery) is needed. That is one way to address the issue (regularly using a quality battery maintenance device being another) but it may not be a permanent solution. What is never mentioned in this presentation is that when a battery with more reserve capacity is deeply-discharged, the vehicle's alternator will have to work that much harder in an attempt to fully-recharge that battery (which most end up not doing). Relying on the alternator to do the work of a battery charger can result in a cycle of dead batteries and jump-starts, until either the battery or alternator fails.

My suggestion for the correct battery for 1997-2003 is based on GM recommendations per the service manual. And i would NEVER EVER suggest to use an alternator to recover a deeply discharged battery, thats idiotic!


  • Removing the negative battery cable on vehicles that will be sitting for extended periods of time is also mentioned as an option. However, no mention is made of making sure the battery is fully-charged before the cable is removed. Disconnecting the cable may prevent the battery from being discharged further by the vehicle (beyond the battery's normal self-discharge rate), but if the battery is already discharged to some degree when the cable is removed, the battery may still be sulfating while in storage.

I did mention that the battery should be accurately tested PRIOR to being put away for storage!


  • The “normal voltage” of 12.28 volts shown after four weeks of storage is about 40% discharged for most batteries. Once that battery drops below 12.4 volts, sulfation is forming in the battery plates, which diminishes both capacity and lifespan.
  • For whatever reason, GM has been reluctant to follow the lead of many other high-performance automakers, who include battery maintainers with new vehicle purchases, instead opting to recommend a bigger battery as a solution. The same issues can arise with batteries with more reserve capacity, it will just take longer to happen.
  • Keep your battery fully-charged whenever possible and you will maximize battery performance and lifespan and minimize the chance of these voltage-related issues plaguing your car

Jim McIlvaine
eCare Manager, OPTIMA Batteries
OPTIMA® Batteries (optimabatteries) on Pinterest

Hi Jim,

Thank you for your dialog to assist the members here! Note my responsed in Red, as I was the one who put on the seminars in the video.

Paul
 
Hi Paul, I appreciate your input in this thread. While many folks like to use the term “gel cell” interchangably with "AGM," the fact is, those terms describe two different technologies that should not be confused with each other.The “G” in AGM stands for “glass,” not gel. While it is unlikely a consumer would ever find a gel cell battery to use in their automotive application, if they did, they'd have a battery with very narrow charging parameters that could be damaged by traditional lead-acid battery chargers. This also becomes problematic for owners of battery chargers with “gel” or even“gel/AGM” charger settings, as those settings may not fully-charge non-gel batteries and could damage them over time.

Our RedTop batteries are considered SLI(starting/lighting/ignition) batteries and are not designed or warrantied for deep-cycle use. Our YellowTop batteries are designed and warrantied for both starting and deep-cycle use and are generally considered “dual purpose” batteries in that regard, as most folks would not consider using a traditional deep-cycle battery in a starting application.

We haven't offered pro-ration on our warranties since 2009. Even at that time, the free-replacement period for the RedTop was (and still is) 36 months. The free-replacement period for YellowTops is also 36 months. If a consumer buys our Digital 1200 Charger from us at the same time as a 12-volt battery purchase, the free-replacement warranty is extended an additional 12 months. There are many other brands and manufacturers in the market who offer free replacement warranties in excess of 30 months as well.

While the GM unit may be able to test accurately down to 10 volts, what happens below that level? We routinely see warranty returns that are deeply-discharged down into the single digits, but work fine, when properly-recharged. A simple $10 voltmeter will assist owners in understanding the voltage level of their battery.

While I'm glad you and I both agree that alternators should not be used to charge batteries, I think “idiotic” is a strong term to use for people who do that, some of whom may have been in your audience. I routinely come across folks(Corvette owners and non-Corvette owners alike), who believe it is good practice to periodically start and idle their stored vehicle as a way of keeping their battery charged, when the opposite might actually be happening. I don't consider those folks to be idiots, just uninformed as to what is really going on with their battery and charging system.

This is sometimes perpetuated by people working in the industry, if they jump-start vehicles and tell the owners the battery should be fine after they drive their car for awhile. That happened to my neighbor last week, when his mother-in-law's SUV had a battery discharged down to 5.4 volts and roadside assistance came to his house to give him a jump-start. They told him to let it run in the driveway for 15 minutes and the battery would be fine- it wasn't.

Jumper cables and jump-boxes are the electrical equivalent of a one-gallon can of gas. They can get your vehicle going in an emergency situation, but they shouldn't be relied upon to correct the underlying issue. If people drop a gallon of gas into an empty tank, they'll probably be looking for a gas station as soon as they get their car started. The same should be true for people looking to fully-recharge their deeply-discharged batteries. If we could get consumers to understand just that aspect alone of batteries, you and I would both likely be dealing with far fewer battery-related issues.

My apologies on missing your mention that batteries should be accurately tested prior to being put away for storage.


Jim McIlvaine
eCare Manager, OPTIMA Batteries
OPTIMA® Batteries (optimabatteries) on Pinterest
 
Last edited:
Thanks to both OptimaJim and Paul in this ongoing thread. The information that you both have supplied is very informative and useful. I know that I have learned a lot from this discussion.
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Back
Top Bottom