Recommendation: Odyssey PC680 or PC925 for my build?

My first post on this forum, so let's see how it goes!
I believe I have decided to us an Odyssey battery for my A pickup.
I could mount a PC680 behind the seat or under the dash but I wonder
if it has enough power to depend on for my 383 SBC?
I could move my gas tank back a little and mount a PC925 in the bed
between the front panel and tank, I would think the 925 would have plenty of power.
Let me know what you think and let me hear your recommendations!
Maybe this isn't the right battery. I found out from Odyssey that I cannot
use my battery tender jr. on their batteries, you need a float charge of at least 13.6 volts and the jr. is 13.4 and they say that won't do the job.
The truck I'm building is my avatar.
Thanks!
Joe

I ran the 680 in my 23 for 3 years and it never let me down. That car ran a 9.5 cr 350 Chevy. I was leary about if it would have enough juice to crank my motor because it is only 7 x 7 x 3 inches, but when I spoke to one of the principles at Odyssey he told me he uses the same battery to crank a blown BBC engine in his car.

Sometimes the car would sit for a month or more and never cranked slow or failed to start.

Don

Don,
What do you use for a charger to maintain the battery if it sits for an extended time?

I'm leaning toward the PC680 for It's size and I want it in the cab.

Thanks!
Joe

Joe, welcome to CHR. Our good friend Roger, aka rspears, mounted the battery under the dash on his '33. I think he posted some pics in his build thread, Followed Me Home, '33 Build. He also had a thread regarding what he learned about charging these AGM batteries, AGM Battery Carger Question. Hopefully these 2 links will help you.

Mike

Quote:

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Originally Posted by curmudgeon

Don,
What do you use for a charger to maintain the battery if it sits for an extended time?

I'm leaning toward the PC680 for It's size and I want it in the cab.

Thanks!
Joe

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We have two chargers. I just have a regular old 12 volt 15 amp/2 amp/25 amp starting model, but my Son Don has one of those smart chargers that is set up to do various types of batteries. The very few times (probably twice) that I thought my 23 was cranking slow after sitting for an extended time and had to put a charger on it, I just used my old fashioned one on 2 amps. Maybe not the correct way to do it but it never seemed to affect the battery in any way. I think as long as you don't exceed 13.8 volts it doesn't hurt anything, but that is not a scientific theory. :)

The alternator in my 23 was a 100 amper and it would regularly go over 14 volts, so I kept my headlights on to keep it in the 13.5 range. That never seemed to hurt the battery either.

Don

Quote:

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Originally Posted by Mike52

Joe, welcome to CHR. Our good friend Roger, aka rspears, mounted the battery under the dash on his '33. I think he posted some pics in his build thread, Followed Me Home, '33 Build. He also had a thread regarding what he learned about charging these AGM batteries, AGM Battery Carger Question. Hopefully these 2 links will help you.

Mike

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Mike, you beat me to the punch, again!! Welcome to CHR Joe! Like Mike says, I ended up using an XS Power D680 which is the same case size as the Odyssey PC680 AGM « XS Power At the time I bought, the XS Power units had some pretty good specials going, including free shipping and a free metal mounting case when you bought one of their "packages". Nathan at XS helped me a bunch, and he's posted here a few times, but not lately. You can reach him via e-mail, nathan@xspowerbatteries.com, or call their tech line from the website and ask for Nathan. Like Mike says, I mounted mine centered under the dash to minimize cable length, and put bulkhead fittings tucked into the kickout on the passenger side, hidden from side view, and only about a foot from the starter. Mine is cranking a 347 stroker running 10.3 CR, and knock on wood it's never failed me yet. Don gives a good testimonial for AGM's, too. Not sure about Odyssey, but I use a Battery Tender Plus on mine and it works great (after finding/fixing a bad fuse connector from the factory...) The critical thing with AGM's is that you not allow them to be pushed above 13.8 to 14V or you'll cook the acid from the mats and it cannot be replaced. Nathan will tell you all about chargers, too, including the high capacity units that they use to crank up batteries between runs on racers. My alternator is a 100A unit too, and I have not taken any steps to lower the voltage and have not seen any negatives to date. Look at the links, and if you have questions post them. Lots of guys have been using the AGM's here.