Normally, if a battery experiences a total discharge just once, it is permanently damaged, and may have lost up to 20% or it's ability to hold a charge in the future. That's why true car guys will tell you that if your battery ever goes dead even once, you should get rid of it and buy a new one. Well, I've never done that, and I've gotten away with TOTAL discharge of car and motorcycle batteries many many times, have left those batteries in place and recharged them, and I've done quite well for the past 25 years of driving that way. But an expert wouldn't recommend keeping a battery that has been drained even once.
Now enter the Optima Yellow Top. Legend has it that an Optima Yellow Top is especially made to withstand a total discharge, without damage. Since you are GUARANTEED to eventually have a total discharge on your Vette, this would seem to be the logical battery for you to have. It is HUGELY more expensive than any other brand of battery out there - in the $150 - $200 range. So you decide if this is worth it to you.
Remember, a new battery alone will NOT prevent DBS, since this is a mere fact of faulty engineering on the part of the Corvette itself. The car simply does not go to sleep the way it's supposed to, and it is apparent that at random times, after you think you've shut the car down, some electronic components stay powered on, continually draining the battery while you are gone. When you come back from your 3 day weekend, that battery will be dead whether it is an Optima or not.
So the best protection is to have an Optima Yellow Top battery AND a Priority Start Module installed. Be sure to read the section on Priority Start.
When sellers tell you that a certain battery has the positive terminal on the left, they usually mean "Left as you are facing the car", in other words "the passenger's side". When they say the positive terminal is on the RIGHT, they mean "the driver's side".
For 2005, the Corvette needs a battery with the positive terminal on the "LEFT" --> the D34/78
For 2006 and 2007, Corvettes need the opposite - the positive terminal on the "RIGHT" --> the D35.
Be sure you get this straight in your mind before buying. The table below should help. Also see below for the D34/78 top view.
The real reason to put this page here is to eliminate the confusion over WHICH Optima battery to buy. This is something no one can quite figure out, not even the Optima people themselves. After 3 months of trying, I've finally gotten Optima to send me the correct battery, so let me show you what I've learned. Everything I have learned is in the table below, but I would STRONGLY recommend that you call whatever dealer you're using and discuss this over the phone. I had TWO incorrect batteries sent to me over a 3 month period in spite of long conversations where I told them exactly what I was looking for. You can't be too careful.
For your C6, you either want the D34/78(2005) or the D35 (2006).
The Optima people point out in this video that many factors affect battery life.
Note also that my battery had probably experienced 8 or 9 total discharge cycles in its life - that was in 2007 when I was still figuring out what was causing my DBS and how to deal with it.
You're kind of on your own here. There is no store within 50 miles of me that sells Optima batteries, so I had to look on the web. I eventually got my battery, but it was after an unbelieveable number of delays, mistakes, and a total time period of THREE MONTHS ! I will not list the vendor's name here, and I certainly can't recommend him to you. So I have to leave you on your own. Tim, from Optima, tells me that you can buy Optima batteries at
|The D34/78 Yellow Top, perfect fit for the 2005 Vette|
This is NOT something you should pay someone else $100 to do for you. Removing your battery and installing your new one requires only a wrench and about 5 minutes.
|Pop the hood open, and in the upper left of the engine bay you'll find the battery.|
|Use a 1/2" wrench to detach the battery cables. It's usually a good idea to detach the ground (negative) cable first. Then you'll see that only a single fastener holds the battery securely in place.|
|Closeup of the battery fastener|
|You'll need a 1/2 inch socket wrench with a very long extension to reach down. Once the bolt is loosened, lift the entire unit out - the bolt is attached to the plastic fastener by a clip so you can take it all out at once.|
|The optima comes with a new plastic fastener, but does not come with a new bolt. So save your old stock bolt, attach it to this new grey fastener, and bolt it securely down. |
You'll see that the D34-78 fits perfectly in the tiny battery compartment of the C6.
|Reach down and seat the plastic fastener as shown, turn the screw a few times to get it seated in the hole.|
|You'll need a 1/2 inch socket with a long extension handle to reach in deep enough to get that bolt tightened down...|
|Now tighten down your battery cables. In this case I am re-attaching my "Priority Start" module, which is highly recommended. |
Be extremely careful when doing this. You can really be injured if that wrench cross-connects the battery positive and negative, as I'm very close to doing in this picture.
In fact I learned this the hard way...
|I did touch the wrench across both terminals, and here's what happened - a piece of my hardened wrench was blown off ! |
A battery with 800 cold cranking amps is nothing to play with - be careful!. It's a good idea to stand on a thick carpet, or a rubber mat, and also to wear thick rubber soled shoes when doing electrical work. My racedeck (plastic) flooring may have saved my life.
|Everything in it's final state, with the Priority Start attached. You can see the orientation and the nice fit of the D34-78 battery. Note that this battery also comes with front terminals, which you will not use.|
Now you're invincible! Just make sure you follow the list of things I mentioned above, because a good battery won't do you any good at all if you still have a constant drain on it while it's parked.
Thanks to my buddy Richard, from El Paso, TX for this one. Here's the low-down: He was brave enough to try to install a battery reversed, and it worked out just fine for him!
Well, I didn't think it could be done. But he managed to pull it off. So if you want a small upgrade over the D35, this is proof that you can use the backwards battery trick to make it happen.
Notice the sticker on the battery is upside-down, showing that the battery is reversed in order to allow the cables to reach the proper terminals.
Thanks again to Richard for sharing his experience and his pictures! By the way, he found his Optima at Sears, where they were willing to exchange the battery if it didn't work out for him.