Battery size?

[JimLev]

I don't believe I've seen this mentioned before.
What Group size battery are you using in your '33?
I don't have my car yet but will need to get a battery. LS3 will have power windows, electric power steering, and AC/heat.
Some of the stores around here are having sales on them so I might as well get one now.

[progmgr1]

I was never able to find any good battery info on either forum for the Hot Rod. I bought the Odyssey PC1200LMJT, mainly because Enersys (my employer at the time) listed it as the recommended replacement battery for the 2015 Mustang with the Coyote engine. The assumption being that this would be a good match for my crate Coyote powered '33 with much of the same electrical system and accessories. IIRC, this battery may be the same size as the Optima Group 34/78 (not certain of that - just a comment I had saved in my "Build Tips" file).
HTH,
Keith

[NAZ]

The build manual recommends an Odyssey PC925 or similar size battery. I went with an Odyssey PC925T and it will easily start my 385 CI 11.7:1CR engine in the cold of winter and starting the engine is the biggest load most folks will put on a battery. All your other electrical equipment will be running off the alternator but starting the engine is powered solely from the battery.

[JimLev]

Thanks for the info guys.
NAZ, yours is a pretty light weight battery, did you buy it to keep the weight down for drag racing?

[RoadRacer]

I don't have my car yet but will need to get a battery.

I'll just throw in my 2c.. batteries don't last long, at least where I am, and I assume NM is similar, heat-wise. So I'm pulling my DD battery when I need it, but am waiting until complete(ish) to buy the real one. No point in losing a year of warranty/use.

[NAZ]

JimLev, yes I purchased the lightest weight lead battery that theoretically could start my car reliably and mounted it as far to the right rear as possible. And it seems to have plenty of cranking amps even when the mercury drops below freezing. So this will give you some idea of a small battery choice. Anything with more cranking amps will work that much better if it will fit the location you want to install it in.

[JimLev]

I'll also be mounting it in the back. I bought the IRS, guess I should hold off until the car is here and I see how much room I have to work with.
RoadRacer, that's a valid point. It is pretty hot here in the summer. The garage does have AC, however it's only on when I'm in there.
I do have a few battery tenders that will be connected when the car is in the garage.

[progmgr1]

FWIW, the Odyssey is an AGM construction, not lead plates. Supposedly AGM batteries have a longer life, hold a storage charge longer and are more resistant to temperature extremes and vibration.

I'm mounting mine in the traditional FFR location behind the waterfall and in front of the IRS. However, I will have top access to R/R the battery since I relocated the fuel tank. I don't know if the larger case size will fit through the standard waterfall opening.

[NAZ]

Yes, Odyssey batteries are AGM (Absorbed Glass Mat) and do not have lead plates like a conventional flooded led acid batteries. While lighter than conventional batteries they still contain lead which is one of the heavier elements and even the small Odyssey is rather hefty when trying to build a light car.

If you're looking for a true lightweight battery with lots of power the lightest automotive batteries currently available are the Lithium Ion batteries which are incredibly light and powerful for their size. They are also incredibly expensive costing several times that of a conventional battery. Once they catch on and through economy of scale, I expect prices to drop making these some very desirable batteries in the future.

[JimLev]

Now that you mentioned it I remembered I have an AGM that I bought about 4-5 years ago that I'm using in a kayak. I retrofitted an electric trolling motor with a homebuilt PWM speed controller to it.
The battery is still good, think I'll use the same battery as you NAZ.

[Brave Salmon]

I went with the pc1200 as well because I wanted it in the ffr location. Trunk space is important if you want to go anywhere besides the car show and Odessy has proven reliable in my other machines. The pc925 fits well but the 1200 fits perfectly in my case. It is removable from the front if you use the panel or from below if it's not. I am using sbf 351w, ac, pwr windows, and radio, and if seems to be fine. How would you know otherwise? Good luck. Remember the warranty on any battery you buy will probably be expired before you finish the car so you may want to consider a walmart special until you to the final trim out at completion. Then you will have new warranty all set.

[RBBJ 32 HOTROD]

Nobody puts the battery in the trunk? I got the group 51 like the build manual said but I think it's too small for my sbc with carburetors

[FF33rod]

Nobody puts the battery in the trunk? I got the group 51 like the build manual said but I think it's too small for my sbc with carburetors

Most seem to find the recommended battery works just fine. However, I went with a group 34 Optima Red top and am putting it in the trunk (top shelf, far right as I can without interfering with the trunk hinge.

Steve

[sethmark]

The Gen 2 car specifically calls out putting the battery in the trunk.

[Kamp]

I have used a Walmart 24F in my other rod and have very good service so that's what I am using in the FFR, trunk mounted. trunk tinII.jpg

[JimLev]

The Odyssey PC925 spins my 6.2 LS3 over like it was on steroids.
It's sort of mounted in the trunk. I couldn't see mounting it on the little platform the directions called for. It would be a PITA to replace it from under the car.

DSCN2543.JPG

DSCN2534.JPG

[progmgr1]

I used an Odyssey PC1200 mounted in a battery box in the stock (behind the seats) location. However, I have access from the top since I went with custom fuel tanks and the trunk area is open.
Keith

[kentsplain]

Depends on where you decide to mount. Tall narrow fits well under gas tank om frame mount. Optima from Summit

[Dduty]

Depends on where you decide to mount. Tall narrow fits well under gas tank om frame mount. Optima from Summit

Hey Kent,
Do you have a model number on the Optima?
Denny

[Arm7419]

I used the Braille Lithium ion battery in mine. Weight is 6 lbs.

[NAZ]

I used the Braille Lithium ion battery in mine. Weight is 6 lbs.

I'm interested in a 6lb battery but the tech was new and expensive when I was shopping for one. Model number you went with? What are you starting and CR? How long you been using it? Any comments on performance?

[Old Timer]

I use the red top Optima 34 or 35.

It turns over my 347 with no problems.
I ran on it for 50 miles home when my alternator went out.

It's tough enough to turn over the 460 with 12:1 compression in my old truck.
Also if you want deep cycle, use a SC34DM you can start plus deep cycle

[Arm7419]

NAZ
Braille G30. Expensive. Had it about 6 years now.

[NAZ]

NAZ
Braille G30. Expensive. Had it about 6 years now.

Thanks! Boy they are proud of them but they seem to have good reviews and the weight savings might be worth the $$. I like that discharge curve -- similar to what I see in other lithium batteries.