DeeGee

I've read many posts on batteries over the years on the Forum and I thought it might be useful to post up my thoughts. I’ll accept that I am a little biased and I’m not a fan of AC Delco batteries but I’ll try to be objective not emotional.

I’ll admit, my experience has colored my views. My son’s 98 Camaro had a stock AC Delco battery. It gave good service (6 years) but it eventually leaked. Luckily I caught it before it damaged the car and all it did was leak acid on the garage floor. My own 02 Vette suffered a terminal failure after only 18 months and 8000 miles. It didn’t leak but it died without warning. Luckily I was stranded in the garage not the Mojave Desert. I replaced it with an Optima Red Top which was at that time was well respected. It gave me good service for over 2 years when the car was a daily driver. I then shipped my car to England and the battery sat hooked up for 2 months in transit. Although it fired up with a jump start, the battery would never hold a charge after that so I replaced it with a Yellow Top. In that case I was happy that I knew that I’d killed the Red Top by discharging it. I’d agree that the reputation of the Red Top has since suffered and there do seem to be a lot of failures where I often wonder whether it’s the car not the battery that’s at fault. JMHO. I now have an Optima Yellow Top which is doing well but stays hooked up to a Battery Tender when not in use.

There are a number major types of batteries on the market and the type of battery which suits you depends on your useage. Here’s a good tutorial on the types of batteries on the Optima page:
http://www.optimabattery.co.uk/engli...a/tutorial.htm

The key facts that I take from that tutorial are that:

“a starting battery is designed to deliver quick bursts of energy (such as starting engines) and has a greater plate count. The plates will also be thinner and have different material compositions. A deep cycle battery has less instant energy but greater long-term energy delivery. Deep cycle batteries have thicker plates and can survive a number of discharge cycles. Starting batteries should not be used for deep cycle applications as they will be quickly destroyed. The so-called Dual Purpose Battery is a compromise between the 2 types of batteries. A Gel or Gelled Acid battery is just a “non spill” version of the normal Sulphuric Acid battery. Silica Gel crystals are added or dissolved into the Acid to form a paste or Gel to stop the Acid being a liquid. There are Starter, and Deep cycle Gelled Acid batteries. These are gradually being superseded by AGM batteries. AGM batteries still use Acid, but in this case it can’t spill because it is Absorbed (A) into Glass (G) Mat (M). These offer more cycles, greater performance whether Deep cycle or Starter types. So this is a superior technology to Gelled Acid.”

To check your battery voltage, do not read the DIC when the car is off. The voltmeter is designed to measure alternator output when the car is running. It will always measure an inaccurately low voltage on the battery when the car is off. Anything from 11.0-11.9 is not abnormal in this mode. With the engine on the voltmeter should show between 13V and 14.5V. A better reading can be measured at the battery terminals. Use a digital multi meter if you can. A fully charged battery measures approximately 12.66 V and a fully discharged battery measures about 11.86 V.

When you look for a replacement the shop manual quotes the GM spec for the Vette which requires a Cold Cranking Ampage of 500A and a reserve capacity of 80 minutes. The stock battery part number is 19002277 model # 75P-7YR. There are plenty of choices that meet that spec.

Changing the battery is straight forward.

Disconnect the negative cable first
Disconnect the positive cable
Remove the battery hold down retainer bolt (13mm IIRC)
Lift out the battery
Clean the terminals before reconnecting
Reattach the positive cable and torque to 15 N-m (11 lb ft)
Reattach the negative cable and torque to 16 N-m (12 lb ft)
Reinsert the battery hold down retainer bolt and torque to 18 N-m (13 lb ft)
Don’t forget that if you have a stock radio, turn the security feature off before you start or the radio will lock up.

Battery performance is a difficult one to pin down. I ran a battery poll which started back in August 06 and as of 17 Feb 08 it had about 733 posts (as of today 756 posts) so its getting there as a sample. Here’s a snapshot on that date:

My AC Delco is still performing well 259 35.33%
My AC Delco died but caused no damage 154 21.01%
My AC Delco died and damaged my car or resulted in problems 34 4.64%
I now have an Optima Red Top and it has performed well 204 27.83%
I now have an Optima Red Top but it has given problems 45 6.14%
I now have an Exide and it has performed well 26 3.55%
I now have an Exide but it has given problems 6 0.62%
I now have another type of battery and it has performed well 106 14.46%
I now have another type of battery but it has given problems 13 1.77%

Here’s the link:
http://forums.corvetteforum.com/show....php?t=1469503

Now I’m no statistician but I work with those guys. This can never be scientific because the questions are not perfect. What it does do is give a good subjective view on the major trends.

To get a true figure for the AC Delco (which admittedly is the main battery in use), you need to look at the first 3 lines.

For the AC Delco of 447 total (259 + 154 + 34), there were 188 failures of which 34 caused damage. That’s a failure rate of 42%

For the Red Top of 249 total (204 + 45), there were 45 failures which is a failure rate of 18%. As its an AGM battery its unlikely to damage the car which is why there are only 2 categories.

The samples for Exide and others are too small to be relevant but I’d say the Exide does well.

The poll has probably run its course now because even the best OEM battery is due for replacement by now. What it showed me is that there was too high a failure rate on the original batteries and even though the latest battery is redesigned and probably much better, there are probably many C5 Vette owners out there with an original battery that has a high chance of either failing or leaking and causing serious damage.

The OEM AC Delco battery had a problem and was prone to leaks. When it leaks, acid drips down first onto the battery tray and then works its way down into the wheel well into the area which holds the PCM. On its way it affects the wiring and the vacuum lines and can cause strange electrical and associated problems.

Toxdoc posted up his experiences after his battery leaked and its worth a read to decide whether you want to take this risk

http://forums.corvetteforum.com/show....php?t=1539128

Heres another members experiences:

http://forums.corvetteforum.com/show....php?t=1678032

Heres the problem:



Here’s a pic of the type of damage that ensues:



So, others may disagree with my analysis but of course that’s what a discussion Forum is for.

There’s a lot of discussion on the versions of the AC Delco batteries which are out there. Corvette Forum Member timd38 pointed out that “The AC Delco battery in the picture was made by Delphi, thus the leak issue. Since that time Delphi abandoned the battery business and they are now made to GM specification by Johnson Controls. You can tell the new one ones because they have a different cover on the battery that has service caps that are not to be opened.” Member Dave68 advised that GM started fitting AC Delco AGM batteries in 2001 but that while these won’t leak, they suffer the same weakness as a Red Top, namely that they don’t take well to being discharged. The new top post AC Delco batteries were fitted from 2003 onwards.

In sum it appears that there are 3 types of GM fitted batteries out there:

The original Delphi made batteries fitted from 97 to 01 which are prone to leaks.
Redesigned AGM batteries fitted from 01 to 03 that may die early if discharged.
Further redesigned top post batteries which should be OK. These latest AC Delco batteries have supposedly been redesigned to strengthen the case and should fix the leak problems. In the interest of fairness this is a link to the latest spec:
http://www.acdelco.com/parts/battery...al-battery.jsp

Its an indisputable fact but the C5 has a small drain on the electrics even when idle. If you leave the battery hooked up for months on end, there’s a good chance it will be dead when you come back to it. If you think you may have an excessive battery drain, Bill Curlee posted an excellent guide on how to check for current draw and you can find it here:

http://forums.corvetteforum.com/show...rent+draw+test

If all that fails and you end up with a dead battery, the signs are:
weak or no lights on the instrument panel when you turn the key
clicking from the relays in the passenger footwell (the dreaded chattering relays) when you try to start,
instrument panel lights that dim when you try to start.
There may be others.

I’d say best advice is that if you plan to leave the car idle for longer periods, invest a few $$ on a Battery Tender. This will give the battery a gentle trickle charge and keep it topped off. If your car sits outside, you can buy a solar powered equivalent which may do enough to keep the battery happy. All I'd say is don't neglect the battery for months on end and then complain when it's dead.

So what do I think is the advice I’d offer to a new C5 owner?

Firstly when you're buying, check that the battery has not leaked. A new battery doesn't mean the old one hasnt done some damage. Take a good look around the battery tray for evidence of acid damage.

If you have an older side post AC Delco check for leaks, particularly if its pre 2002. If it has been discharged, it has probably been taken out of the car and the leads may have been over torqued on reinstallation. Over torquing stresses the case around the side posts. Better still, change it as a precaution because the older AC Delco’s are prone to leaks and particularly vulnerable around those side post connections.

If the thought of a leak worries you, buy an AGM battery. If not, there are cheaper batteries on the market. Ultimately its your $$ and your risk.

If your car is a daily driver, don’t worry about drains. It will almost certainly fire up like a Champ every day. If you regularly leave your car for a week or longer, buy a Battery Tender. If you have an AGM battery, make sure the tender is designed for that type of battery.

Bottom line for me is that I have no axe to grind either way but I have my views, colored by experience. I’m not an AC Delco fan but I’ll happily accept that the 03 onwards batteries are better quality. It’s your choice but hopefully this thread will allow you to maker an informed decision rather than rely on instant judgements from a single thread.

Sorry for the long post but hope this helps

jdmvette

that's a very informative, great post.

rcs128

Wow, fantastic post. Thanks for compiling all that.

I have two comments: Like you said, it's impossible to scientifically rate the OEM battery by assigning it a "failure" value, since it is in effect a wear item -- designed to last, or "fail" (via lack of charge capability), after 5-6 years. To say that all these AC Delco batteries are failing is like saying that for many owners the stock Runflat tires are failing... they're not, they're just aging to a point where the serviceable life has ended and owners replace them with a new set. The only true verifiable "failure" of a battery is when it leaks. Individual use and care (and the condition of a vehicle's electrical system) have far more effect on battery life than does manufacturing.

Secondly, do you have any idea if the circa 97-2000 AC Delco batteries were prone to leak in other GM cars? It would be interesting to see if the common denominator is the battery or the car.

Overall, I'd say that proper care and attention is the key to reliable battery life. Like you said, put it on a tender (or disconnect it) if the car is going to sit for an extended time. If you pay attention, a battery usually gives you signs that it's getting near the end of it's life... a little slower to crank, a little slower to get the volts back up after a start. And if you're aware of how old the battery is, you should know in the back of your mind that a replacement will be due sooner or later. It's up to the individual to decide if they want to replace a reliably-performing battery before or after it ultimately goes.



Rich

Sportsdude

Thanks for the nice write up

DeeGee

Very good points Rich. I agree completely although the poll was running for a few years.

cedge

you are correct. but there will always be those who will knee jerk react to a thread, and not wait to see the full picture.

Z06-JIM

Great write up and info Dave... ..thanks for sharing...

timd38

FYI, the Delco battery you have in the picture was made by Delphi, thus the leak issue. Since that time Delphi abandon the battery business and they are now made to GM specification by Johnson Controls. You can tell the new one ones because they have a different cover on the battery that has service caps that are not to be opened.

Also, if an Optima battery becomes very deeply discharged, the purity of lead used in an Optima is so high that the internal resistance becomes to low to turn most home battery chargers on, so you want to connect it to another battery to create the resistance required to turn the charger on.

The company I work for makes over 110 MILLION AUTOMOTIVE batteries a year, so say what I say for what it is worth.

DeeGee

Good to know and thanks for the info. It would be good to be able to let owners know how to identify a Delphi made battery.

VRROOOM2

VERY informative post Dave, Thanks!!

rcs128

That's great info.

C5R USA

Very detailed well written statement,you've done your homework

istsme98

Great info

DeeGee

Too long reading battery threads on the Corvette Forum

Wheelboyo

A great writeup DG. My '04 C5 came with a top post battery and not a side terminal. So I'll assume us guys are safe from the dreaded LBS.

jmc12

Don’t forget that if you have a stock radio, turn the security feature off before you start or the radio will lock up.

How do you do that ???? By the way that's a great read......

DeeGee

Here you go:

Theft-Deterrent Feature
THEFTLOCK is designed to discourage theft of your radio. It works by using a secret code to disable all radio functions whenever battery power is removed. The THEFTLOCK feature for the radio may be used or ignored. If ignored, the system plays normally and the radio is not protected by the feature. If THEFTLOCK is activated, your radio will not operate if stolen. When THEFTLOCK is activated, the radio will display LOC to indicate a locked condition anytime battery power has been interrupted. If your battery loses power for any reason, you must unlock the radio with the secret code before it will operate.

Activating the Theft-Deterrent Feature
The instructions which follow explain how to enter your secret code to activate the THEFTLOCK system. It is recommended that you read through all nine steps before starting the procedure.
If you allow more than 15 seconds to elapse between any steps, the radio automatically reverts to time and you must start the procedure over at Step 4.

1. Write down any three or four-digit number from 000 to 1999 and keep it in a safe place separate
from the vehicle.
2. Turn the ignition to ACC or ON.
3. Turn the radio off.
4. Press the 1 and 4 pushbuttons at the same time. Hold them down until --- shows on the display.
Next you will use the secret code number which you have written down.
5. Press MN and 000 will appear on the display.
6. Press MN again to make the last two digits agree with your code.
7. Press HR to make the first one or two digits agree with your code.
8. Press AM FM after you have confirmed that the code matches the secret code you have written down. The display will show REP to let you know that you need to repeat Steps 5 through 7 to confirm your secret code.
9. Press AM FM and this time the display will show SEC to let you know that your radio is secure.
Unlocking the Theft-Deterrent Feature
After a Power Loss Enter your secret code as follows; pause no more than 15 seconds between steps:
1. Turn the ignition on. LOC will appear on the display.
2. Press MN and 000 will appear on the display.
3. Press MN again to make the last two digits agree with your code.
4. Press HR to make the first one or two digits agree with your code.
5. Press AM FM after you have confirmed that the code matches the secret code you have written down. The display will show SEC, indicating the radio is now operable and secure.
If you enter the wrong code eight times, INOP will appear on the display. You will have to wait an hour with the ignition on before you can try again. When you try again, you will only have three chances to enter the correct code before INOP appears. If you lose or forget your code, contact your dealer.

Disabling the Theft-Deterrent Feature

Enter your secret code as follows; pause no more than 15 seconds between steps:
1. Turn the ignition to ACC or ON.
2. Turn the radio off.
3. Press the 1 and 4 pushbuttons at the same time. Hold them down until SEC shows on the display.
4. Press MN and 000 will appear on the display.
5. Press MN again to make the last two digits agree with your code.
6. Press HR to make the first one or two digits agree with your code.
7. Press AM FM after you have confirmed that the code matches the secret code you have written down. The display will show ---, indicating that the radio is no longer secured. If the code entered is incorrect, SEC will appear on the display. The radio will remain secured until the correct code is entered. When battery power is removed and later applied to a secured radio, the radio won’t turn on and LOC will appear on the display. To unlock a secured radio, see “Unlocking the Theft-Deterrent Feature

If you do manage to lock it up and dont have the code, here's the How To Unlock it:

https://www.corvetteforum.com/techti...=164&TopicID=1

jmc12

Thank's DeeGee, I did not know about the radio lock up... Also after reading your thread I am off to get a new battery, mine is original 03..
Thanks again for all your research and you service to the USA..

travelingypsye

Once again, a very well written post. Thank you for the info.

AC54ME

Dave,

Great write up on a common issue.

Have you asked for this to be posted in the Tech Tip stickey?