Question about Odyssey batteries

[Bmachine]

I read that several people here are running Odyssey PC680 batteries. It's an appealing option but I am puzzled by the CCA numbers. It is rated at 170. I believe most batteries used by these cars are rated between 400 and 600.

I see that some (like Erik and Sven I believe) are running two PC680 in parallel to compensate for that but I think I also heard some running only one. Am I missing something here? Is 170 CCA enough to run a coupe without problems?

Thank you.

 

[teahead]

I would definitely run at least two.

 

[aearch]

I HAVE TWO YELLOWS

 

[Bmachine]

Based on a post he made a while ago, Decoupe is happily running with only one, seemingly without problems...

 

[Markos]

Based on a post he made a while ago, Decoupe is happily running with only one, seemingly without problems...

RIP Decoupe...

Sadly, I did some more research and found that Doug was killed after sustaining injuries in an avalanche while back country skiing near Golden, BC Feb 24, 2016.

 

[Bmachine]

RIP Decoupe...

Oh nooo! Terribly sorry about that. I did not know.
My apologies.

 

[Ohmess]

I used a single Odyssey PC680 before my voltage regulator went kaput and allowed 19.3 volts into my electrical system. This wiped out the battery, so my experiment was short lived, but during mild weather with a well tuned car it was not a problem. In cooler temperatures I would be very nervous about this setup, and had plans to go with a dual setup wired under the rear seats. I may yet go back to that idea.

 

[Bmachine]

Thanks Chris. I remember reading your adventures on that front. Very interesting.

The more I read about it, the more it seems that plenty of people use a single one (including on Corvettes!) without problems ... as long as you are not in an area with long cold winters. So it should not be a problem in CA. And even if it turns out to be an issue, it is fairly easy to add a second one if space was preserved for it.

 

[Markos]

I would be worried about that first start on a carved car after sitting for a month. Odyssey basically invented a new metric of Pulse Cranking Amps, which is essentially the draw on a healthy fuel injected car that starts within three seconds. After sitting for two months, my car takes about 15-30 seconds total cranking and pumping and what not before firing up. At the very least, install a check valve on your fuel line.

 

[Bmachine]

Good suggestion Markos. Although in my case I am converting to FI and my Webers will be in the For Sale section soon.

 

['69 2800cs]

I run a single PC680 in my 911. It was workable when I had an EFI motor and it was warm out but if it's been cold or the car has been sitting it needed a charge.

Now that I have a carbed motor it's a problem. Everything on the motor is in top shape but with no chokes you've got a few seconds of cranking before it dies.

This is on a track car with no AC, radio, nothing. Leave your parking lights on for 5 minutes at the supermarket? You'll need a jump.

 

[jmackro]

If your goal is to save weight, nothing will be lighter than a single Odyssey. But as others have said, don't take your coupe on a ski trip!

If your goal is to mount the battery under the rear seat(s), there is another alternative: two, 6V Optimas wired in series. These are rated at 800 CCA, so mechanical fuel pumps, cold weather, weeks between starts, etc. should be less of a problem. The only downside is that these things are fairly pricey.

 

[Bmachine]

I run a single PC680 in my 911. It was workable when I had an EFI motor and it was warm out but if it's been cold or the car has been sitting it needed a charge.

Now that I have a carbed motor it's a problem. Everything on the motor is in top shape but with no chokes you've got a few seconds of cranking before it dies.

This is on a track car with no AC, radio, nothing. Leave your parking lights on for 5 minutes at the supermarket? You'll need a jump.

Great info, Todd. Thank you.

 

[Bmachine]

If your goal is to save weight, nothing will be lighter than a single Odyssey. But as others have said, don't take your coupe on a ski trip!

If your goal is to mount the battery under the rear seat(s), there is another alternative: two, 6V Optimas wired in series. These are rated at 800 CCA, so mechanical fuel pumps, cold weather, weeks between starts, etc. should be less of a problem. The only downside is that these things are fairly pricey.

Good suggestion, thank you Jay. But yes, at $187 each that gets right up there!

 

[Ohmess]

My car has carbs, so I did not need to take into account the extra jolt that may be required for a fuel injected car.

As to Jay's comments, my goal was not only to save weight, but to move the weight from high up and outside the wheelbase to as low and as centered as possible. I realize the performance benefit from this would probably be minimal, but was planning to do it anyway.

 

[Bmachine]

To button up this thread, my experience has revealed the following:

Running a single Odyssey PC680 under the rear seat is simply not enough. Car would only start without help one out of every 4 times. And that is in average 60F temps. Carl nelson says it is because of the length of the wire going from the rear seat to the engine bay. Even with 2 gauge wire.
So I added a second battery in parallel and that now works great.

In conclusion, it would appear that a single PC680 could work if it is reasonably close to the starter motor. But distance really taxes the relatively meager 170 CCA.

 

[Jellobmw]

I have found an Odyssey is big enough for my motorcycles (Laverda 3CL and BMW R1200C) but in my e9 i run an Optima I got at Costco. The lady I bought the Odyssey from said it had power enough for her small block V8, but I remain skeptical........