Odyssey battery for a 3.2

[911/914gary]

My battery is dead in my ’85 Targa. Since I don’t drive my car often the battery doesn’t get re-charged adequately. I am looking at other battery options (other than a plugged in battery tender) like a battery with a deep cycle quality. There have been several discussions regarding the use of Odyssey PC925AGM type battery with a Carrera 3.2 engine. The recommended standard battery is this monstrous group 49 wet cell battery with a CCA rating of 805 amps. The PC925 is rated only at 330 amps which seems underrated for this application. Am I misunderstanding something about this rating?

[KTL]

Lots of guys have used the Odyssey 925 with a dedicated mount tray like Rennline's. No issues with the CCA rating of the battery.

For comparison, i've used an Odyssey 680 powersports tiny battery in my former '87, current '86 for a number of years with no issue. But I don't drive them year'round. So in the cold season I think they smaller batteries would be a big risk. Warm season, the small Odysseys work fine.

[Brando]

Derp... Disregard.

[911/914gary]

So the PC925 is a red top. What is the equivalent yellow top?

[Barrpete]

Originally Posted by 911/914gary

So the PC925 is a red top. What is the equivalent yellow top?

I think the red top / yellow top is Optima not Odyssey.

[Brando]

Originally Posted by Barrpete

I think the red top / yellow top is Optima not Odyssey.

Yup. I misspoke.

[JohnJL]

I had a few Odysseys die on me, and of course Optimas are not what they used to be.

I am on the Braille channel now. Great experience with their small one turning over a high-compression, supercharged motor (ie lots of load) in an admittedly mild Canadian winter. I will get another of those.

[Driven97]

Pretty sure they're all made by Deka.

[JohnJL]

My optimas look nothing like the odysseys which look nothing like the brilles, which I have heard are dekas but i cant confirm. They all use different hardware, casing, had different performance for me, and weighed different.

[Crude Rudy]

I had 2 Optimas die on me in 3 yrs, switched to a sealed Lead Acid 4 yrs ago - no more problems.

[Techno Duck]

Ive had good luck with the Odyssey batteries. A PC680 that is still going strong, i forgot how old it is but easily 7+ years. PC925 in both my track car and 3.2L. I travel often for work and used to keep the 3.2L on a battery tender. Recently i have just started disconnecting the battery with one of these, takes a few seconds.

http://www.amazon.com/Post-Battery-Master-Disconnect-Switch/dp/B001N729FS/ref=sr_1_1?ie=UTF8&qid=1454991798&sr=8-1&keywords=battery+cutoff

If you go long enough not driving your car that its draining a stock size battery, the Odyssey wont do any better. You want to look at a battery with more Amp-Hours; the PC925 is 28aH. Most of the Optima's are nearly twice that around 50aH. A group 49 sized AGM or lead acid is probably 90ah+.

How long are you going between starts? My 3.2L went 3 weeks with a fairly new standard size battery in AGM, no tender and didnt disconnect, it barely had enough juice to start. This was in SoCal so it wasnt even that cold out. You may not have a choice and may need to just disconn the battery or leave it on a battery tender.

[911/914gary]

My last wet cell Diehard lasted ~4 years. For the cost the AGM batteries seem to be the better option.

[Arne2]

Th PO installed a PC925 in my '84 over 5 years ago? Still working perfectly. I do put a tender on it if I'm going to go more than 10-14 days without driving it. But for normal use ( a couple of days per week) it keeps up just fine.

[flyenby]

I have had good luck with interstate.....costco now sells them

[911/914gary]

Hey Flyenby. What type Interstate did you get?

[Quicksilver]

I got over ten years out of my first PC925. (12?) That included some abuse like running it totally flat a couple times. Towards the end of its life I found out from a distributor that they recommend a different charging method for an Odyssey that is totally flat. They said that it is best to do the beginning of the charge at a rather high rate.
This method worked the last time I totally flattened the battery. A normal 10 amp charge wasn't bringing it back to life so I hit it with the "Start" setting on the charger. I gave it about ten 5 minute cycles on the Start setting and then switched to a normal charge and I got more then another year of normal service out of it.

Now I'm on the 2nd Odyssey PC925 and very happy with it. That said I'm really impressed with the specs of the Braille batteries plus the price. I'd like to hear some long term reports on them but if I get a 2nd sports car I'll probably try one.

[dad911]

Originally Posted by JohnJL

I had a few Odysseys die on me, and of course Optimas are not what they used to be.......

Originally Posted by Crude Rudy

I had 2 Optimas die on me in 3 yrs, switched to a sealed Lead Acid 4 yrs ago - no more problems.

Same here, but three Optimas in less than 2 years. Used to use like them, never again.

[911kevin]

The Interstate, MT5 AGM 48/H6 was a direct fit in my 89 (using the inner bolt hole). Classic look and easy to install since fairly compact compared to the larger groups size. Has worked just fine for about four years.

[Tremelune]

More info here:

http://forums.pelicanparts.com/porsche-911-technical-forum/900071-once-again-batterys-im-new-gimme-break.html

Summery: Battery life comes from behavior, not brand; stock batteries are way over-specced for cars that aren't driven daily in extreme weather; Deka and Braille batteries are identical—both made by East Penn; a PC680 will start the car fine.

[KTL]

My Odysssey 680 is almost 8 years old and gets infrequent use. I've used it in three different cars- the '87 street/track fun car, the racecar and now in the '86 street car this past fall. I simply put it in the '86 because I acquired the car with a wiped out standard "wet" battery and I needed something to be able to drive it.

Over the years i've put it on an appropriate trickle charger to keep it from going flat. I definitely got my money's worth out of that battery. But it's to the point now where i'm expecting it to soon be dead and it's on my list of things to replace.