Light weight battery suggestions

IMR-Merlin · 12-25-2014, 06:31 PM

As the title says, I am looking for a lighter and smaller battery for my 930 project car that I am building. Any input would be greatly appreciated.

Here's a pic of the project to date.

Thanks in advance for any input.

Brendon

Cajundaddy · Cajundaddy's Garage

This thread is really pretty thorough.
Poor Man's Lightweight Battery

I have run the 16lb Odyssey 680, the 19lb Deka ETX20L, and the 5lb Shorai LFX36 over the last 5 years of TT competition. Because my car doesn't get used daily and has inherent current loss due to active electronics I must keep it on a maintainer or the battery will go flat. If they are fully charged and in top condition they will all start the car. After damage from a few flat battery events they will sometimes not get it done. I recently put a full size AGM back in the car for peace of mind.

IMR-Merlin · 12-26-2014, 05:36 AM

I can't use a full size battery. Does anyone know what the cold cranking amps of the factory battery are? I may just look for a gel cell that fits.

moneymanager · 12-26-2014, 06:32 AM

Get a Braille. Comes in several sizes/CCA ratings. Mine's a 3121 in a 2.7. I keep it on a maintainer most of the time. 21 lbs, agm.

IMR-Merlin · 12-26-2014, 06:48 AM

Quote:

Originally Posted by moneymanager

Get a Braille. Comes in several sizes/CCA ratings. Mine's a 3121 in a 2.7. I keep it on a maintainer most of the time. 21 lbs, agm.

I was looking into them, but I have read that they are just re-labeled DEKA batteries. This car will be road used, so I may need to keep it off a maintainer for a week at a time.

Thanks for the input.

Brendon

moneymanager · 12-26-2014, 07:04 AM

Lots of people use the heavy and bulky Optima.
Actually the Deka etx 30L and my Braille 3121 looked like the same battery when I bought them, but the Braille had 550cca vice the Deka's 365...very different batteries though external appearance is the same. But many people including me think an AGM battery lasts longer/works better if kept on a maintainer most of the time.

SiberianDVM · SiberianDVM's Garage

I went with an Interstate Megatron II in size 24F. It's a lead acid about the same height and width as the huge thing that was in there, but about 4-5 inches shorter in length and about 20 lbs lighter, at around 35 lbs. Since it does not have lower edge lips like the original battery, I did have to fab up a custom bracket.

IMR-Merlin · 12-26-2014, 07:30 AM

Quote:

Originally Posted by SiberianDVM

I went with an Interstate Megatron II in size 24F. It's a lead acid about the same height and width as the huge thing that was in there, but about 4-5 inches shorter in length and about 20 lbs lighter, at around 35 lbs. Since it does not have lower edge lips like the original battery, I did have to fab up a custom bracket.

This is what I might do.

How is it for hot starts?

I still have the height, but my bracing gets in the way of the length. This is a "street" car so I'm willing to sacrifice a little bit for reliability.

Thanks again for all the input.

michael lang · michael lang's Garage

I put a Braille battery in my car as well. Also installed the battery cage to keep it from sliding about on the tray. I liked it because it is a dry cell so I will not have to worry about leaking acid. Yes, I do have to keep it on a Battery Tender but that doesn't bother me much because I don't drive everyday unless it's a track weekend and my car is street driven as well, I have to get to the track somehow. I've had it for about three years.

SiberianDVM · SiberianDVM's Garage

Quote:

Originally Posted by IMR-Merlin

This is what I might do.

How is it for hot starts?

I still have the height, but my bracing gets in the way of the length. This is a "street" car so I'm willing to sacrifice a little bit for reliability.

Thanks again for all the input.

Never had a problem with it. I just bought the same battery again to use in my ChumpCar racer, a 1989 Supra. At $106, it was the best bang for the buck.

campbellcj · 12-26-2014, 08:43 AM

I have been using the Odyssey PC680 for many years with great results. I keep the battery disconnected while the car is parked, sometimes for weeks if not months, and it holds a charge that way just fine. I don't deal with super cold temp starts so can't talk to that.

IMR-Merlin · 10:58 AM

Quote:

Originally Posted by SiberianDVM

Never had a problem with it. I just bought the same battery again to use in my ChumpCar racer, a 1989 Supra. At $106, it was the best bang for the buck.

I just picked up the MT-121. It has the same CCA and CA as the MT-24 but is about 2" shorter (8lb lighter also) in length and barely fits.

Only thing I don't like is the pole positions.

Thanks for all the input gentlemen!

http://www.atbatt.com/interstate-mega-tron-ii-mt-121r-automotive-battery-600-cca.asp

SiberianDVM · SiberianDVM's Garage

That is a tight fit you have there.

With some good terminal insulators, it should be fine.

Spend some time fabbing a good hold down system, especially for a car that will see the track. I spent about 2 days on mine, cutting and welding, grinding and painting, drilling and bolting. The tech inspectors at the DE were impressed.

Then the idiot that ran into the left front corner of my car destroyed the whole thing.

IMR-Merlin · 12-26-2014, 02:00 PM

thanks, time and fab skills are some things I have an abundance of this winter.

here's a pic of how the car started.

Everything has been done in my 2 bay garage at my house.

SiberianDVM · SiberianDVM's Garage

Kudos for rescuing her from the graveyard. And I'm jealous of the garage. I have to work in a carport.

DHE11 · DHE11's Garage

+1 on the Odyssey.
I fitted a PC680 two years ago and no issues as either a daily driver, or track use with 2-4 weeks between drives. As above, I've I fitted a cut off switch and found it will last for months and start no problems.
I don't use the maintainer aside from giving it a top up every 3-6months.
Easy installation and very light compared to standard.

175K911 · 01-01-2015, 04:55 AM

+2 on the Odyssey PC680, though I use the PC680 MJT in both my cars- the 911 and my SpecMiata race car. The MJT is Metal Jacket- basically an aluminum box around the battery.

I will say that in both cars I have a Schneider battery maintainer permanently mounted in the cars right next to the batteries and connected to the battery terminals. This way I just pop open the front trunk (rear trunk on the SM) and plug in whenever the cars aren't in use. The Schneider is smart enough to cycle on and off to keep the batteries properly charged without overcharging.

Matt Romanowski · 01-01-2015, 05:56 PM

Use some heat shrink on the the brace to help insulate it.

IMR-Merlin · 01-04-2015, 06:55 AM

Quote:

Originally Posted by Matt Romanowski

Use some heat shrink on the the brace to help insulate it.

I was thinking of using some padding like on a BMX bike if I don't like the tolerances. I still have to cut out the old battery mount which will give me an additional 1/2" clearance from the brace.

Plavan · Plavan's Garage

Odyssey PC680

Keep in mind fellow Odyssey owners- To get the most out of the battery you need a special charger and do not use battery tender devices. The Float is alot higher than a typical charger. Otherwise you are damaging them.

Approved chargers:
http://www.odysseybattery.com/documents/ODYSSEYapproved12VchargersApr2014.pdf