chardonet

I am thinking of replacing the OEM soon with the Odyssey 925. Any negatives about this in a 997 GT3? The car does not sit any longer than 2 weeks without a start-up. Also have the Porsche/Ctek charger.

Should I consider the Rennline battery mount, or will the unit fit right in there?

Thank you in advance!

Carrera GT

It needs a bracket. Note that you don't need the "metal jacket" version. Search for examples of installs of that (and lighter) batteries.

chardonet

Thanks for the advice!

The Baron

I have Odyssey batteries in several Porsches and other toys.
(3)'65
(1) '70s
(2) '76 Turbo Carrera
(1) GT3rs
(2) Mil-spec Humvee
(2) BMW GS1150 Adventures


Awesome batteries

Once a year (pick a date that you remember ie: July 4, New Years day, etc.) and turn your headlights on and run the Battery down ....... I mean DEAD.

Then, put it on the Odyssey recommended charger and charge it back up.

I've had a few of my Odysseys since January 2001 and they're still perfect

This is the recommended procedure from Odyssey.

Hope this helps,

Chuck

Carrera GT

Check with the Odyssey folks before you ascribe to the practice of running a lead-acid battery dead flat.

Having seen PC925 Odysseys destroyed for no apparent reason of mechanical damage or old age, I think it comes down to the rather short charging cycles these batteries expect.

http://www.odysseybatteries.com/charging.htm

Note that a typical charging cycle is only about two hours at a paltry 10 amps. The batteries I've seen killed were likely left on 6 amps for 12 hours (overnight or longer.)

Now imagine a smaller battery in a motorcycle or a lightweight jet ski battery (which I use in my GT3.) I let it burn down to an 80% SOC for tasks like running an tire inflator and then charge it using 6A for 1 hr (no longer than it takes to make lunch) then put it on the Deltran Battery Tender indefinitely. This simple regime has been how I fight the apparent design fault in the 996 and 997 GT3 -- both of which destroy batteries by depleting them to almost zero vaults. Conversely the PC 925 in my 993 has lasted since circa 2003 and invariably answers the key even when left standing for months (with winterizing spray in each cylinder) just with the Deltran plugged in. The same is true for two motorcycles, two jet skis, a snowmobile, three generators and a wood chipper. All of which run (relatively) cheap AGM (aka "glass mat") batteries. Even the Ducati now has a generic AGM and it turns over cold so fast I wonder if it's almost too fast for the oil to reach the bearings!

The Baron

Just telling what has worked for us for over eight (8) years.

The advice was personally told to me by our motorsports liaison at Odyssey.......

But I guess he's an idiot...... I'll let him know that you said so.

Carrera GT

Your reading compression is exceptional.