When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I was skimming thru this thread and was going to ask your current thoughts.
I think i I'll try one instead of the Bosch replacement I was just getting ready to buy.
do you drive car every 3 - 4 days at least?
If not, do you use a tender?
My car is 99% track use so it generally sits for weeks at a time between track events but I have it hooked up on a fender. I have had it without a fender for over a week and it always started without any problems. The car cranks just as hard with the 21 as it did with a full size one which interestingly did not last very long. I think with any battery, if the car is not basically a daily, it helps to put it on a fender when sitting in the garage for days at a time.
I noticed a trend of incorrect weight values in this thread for the original 2004-2005 GT3 battery. The GT3 model of 996 series was fitted with a lighter weight battery and less powerful. 60 Ah 280A and usually a Moll brand battery. Battery wet weight is 35.3 lb. Part number was 999 611 060 20 but has new number now, 999 611 060 21. Also note that the original battery was about 9 3/8 inches long while the 70Ah battery is about 10.25 inches.
In many cases the original battery was replaced with a more common size battery that was heavier, longer, and had more power capacity.
Here is another good set of posts on replacement batteries.
I have used Odyssey and Braille in many different cars over the years. I stopped, life is too short, they are just such a PITA. I always have them on trickle chargers but they tend to wear out quickly anyway. I would say the lifetime of these batteries is 1 year before they just don't perform as well any more. I went with Bosch and/or INterstate and spend my new free time thinking about my corner speeds and braking. Sorry I don't have anything more in the terms of data, just my experiences. I am sure some will say I don't know how to trickle charge or whatever.
Originally Posted by kgorman
Backing off from my initial negative nancy position..
The interstate I had died after about two years. Always on a battery tender, but I forgot for a couple weeks while I was on vacation. Guess what? It's dead and won't come back.
The way I am figuring it is in my experience all batteries have a limited lifetime, somewhere around 1-3 years. The small Odyssey was just one season, the Interstate was 2 years. Based on this info, why not try these small Deka batteries and see?
Need a new battery. Replacing a heavy Interstate battery that came with my 6gt3 (which I bought six years ago and drove for 10k miles). Battery finally died the other day after problem-free six years (plus unknown original owner's time). The car is a back-roads driver driven 1-2x/week and always on battery tender when parked. Sometimes not driven for weeks. Not driven winters -- parked and on batt tender.
So what's the final verdict on these little Odyssey/Deka type batteries? They are only 20Ah capacity vs the 70-80Ah of the larger/heavier units so probably working much harder to keep up hence seem to die sooner. Seems like there's no free lunch re battery weight, or is there? Should I just go to Auto Zone, Advance Auto Parts, or Walmart and get whatever pedestrian heavy batteries they have there?
I have an Odyssey 925 with the Rennline mount and their optional cut off switch. Had the same setup on my prior 2003 C2 which I moved over to the GT3. The car sits for weeks between drives and I remember to put on the charger about 50% of the time. It starts every time no problem.
Just came back from Advance Auto Parts and got their AutoCraft Platinum AGM monster. Car starts much better. Poor old battery, must have been near dead for almost a year.
I just killed my 2nd Odyssey 925 and want to try something different. For the folks using the Die Hard Group 47 batteries - these look like conventional lead acid batteries. Have you had any issues with sloshing/spilling battery acid while on track? Is there an AGM that bolts into the stock hold down locations?
I just killed my 2nd Odyssey 925 and want to try something different. For the folks using the Die Hard Group 47 batteries - these look like conventional lead acid batteries. Have you had any issues with sloshing/spilling battery acid while on track? Is there an AGM that bolts into the stock hold down locations?
My AGM from above fits the stock hold-down location. Any parts store will have a computer that pops out batteries that fit your year, mark, and model car, including the gt3.
I bought a Champion H5 (same as Group 47) AGM from Pep Boys. It's a perfect fit in the 996 battery tray - the battery feet on 3 of 4 sides are captured by the tray. Because the H5 is less than 10 inches wide, the positive battery cable needs to be tugged a bit to get over the top of the terminal, but it has adequate slack once it slides down into position.
IMO, H5/Group 47 is the ideal size for the GT3 if you're not using a custom mount and want to use the built in retention features of the OEM tray. It's no bigger than it needs to be, but any narrower and the positive battery cable wouldn't be long enough. It weighs 38.5 lb as measured on my bathroom scale. Not as light as my Odyssey 925 (25 lb with Rennline mount), but probably about as good as you can do with a full size battery that is retained by the stock tray. 750 cranking amps should be plenty.
I called 4 different stores and all of them insisted that my car needs an H6 or H7 battery, which would fit but would be bigger and heavier than needed.
One question: The vent tube on my car is a female and so is the vent hole on the battery. Any advice on how to connect the two?
Update... the Deka battery has been solid, but I’ll be honest I haven’t done a ton of miles in the car since install. But they have been good since they have been on the new charger (see below) - cranks strong all the time. They are no worse than any other battery I’ve had including interstate, odyssey and optima. IMHO I would stick with some brand of AGM, or go lithium but anything else is for the dogs at this point (2018).
Here is an additional data point for what it’s worth. I’ve upgraded my chargers to Victron Energy units, and immediately they went on bulk, meaning the battery tender brand I was previously using weren’t charging these batteries well.
Now I am thinking what if I had a better charger before?
Been hawking this as I feel an impending battery replacement...checked out the Victron charger and it appears to be well engineered with bluetooth and the whole 9 yards (hoping that the waterproof feature is never needed tho!).
I've had my old BMW charger for so long that I wasn't in the market for another charger but crossed paths with
and it currently tends to the battery on the GT3. This little sucker is pretty slick- we'll see how long it lets the current Interstate battery reside in place while I toss around the options y'all have discussed.
Last edited by teamgomez; 09-05-2018 at 02:49 AM.
Reason: typo
I bought a Champion H5 (same as Group 47) AGM from Pep Boys. It's a perfect fit in the 996 battery tray - the battery feet on 3 of 4 sides are captured by the tray. Because the H5 is less than 10 inches wide, the positive battery cable needs to be tugged a bit to get over the top of the terminal, but it has adequate slack once it slides down into position.
IMO, H5/Group 47 is the ideal size for the GT3 if you're not using a custom mount and want to use the built in retention features of the OEM tray. It's no bigger than it needs to be, but any narrower and the positive battery cable wouldn't be long enough. It weighs 38.5 lb as measured on my bathroom scale. Not as light as my Odyssey 925 (25 lb with Rennline mount), but probably about as good as you can do with a full size battery that is retained by the stock tray. 750 cranking amps should be plenty.
I called 4 different stores and all of them insisted that my car needs an H6 or H7 battery, which would fit but would be bigger and heavier than needed.
One question: The vent tube on my car is a female and so is the vent hole on the battery. Any advice on how to connect the two?
I ordered this from Amazon and used the 2x male elbow to connect the car hose with the female vent outlet on the battery’s side. Remove the black extender that you hold on the pic:
I ordered this from Amazon and used the 2x male elbow to connect the car hose with the female vent outlet on the battery’s side. Remove the black extender that you hold on the pic:
09-06-2017, 04:47 PM
