MIATA or similar battery and attachments - bottom line?

[Craig 930 RS]

I ran a search for these items and came up with bits and pieces of information.

Where is a good place - with good prices - to purchase a small battery with the proper hold down for a 79SC?

TIA,

[speeder]

Craig, I went through this same little research project and wound up just finding a cheap, light battery that works great at Pep Boys or Auto Zone. It is shorter than stock, so you will have to improvise a little w/ the mounting, I used a novel (and cheap SOB), approach that I will post pictures of when I get to my car later.

I will also get the model # of the battery for you then. When I checked at my FLAPS, the one listed for Miata was way too heavy for me. You should have seen the looks I got w/ my bathroom scale, weighing myself+ various batteries as they brought them out.

[MichiganMat]

Im running a WestCo miata battery to turn over my 3.0L and it works great. Fits in the smugglers box pretty well too. I made my own tie-downs from aluminum stock some small nuts/bolts from the hardware store. Battery cost was $110 from the local battery shop.

[masraum]

You can get the red top optima. It's small and light.

when going to an auto parts store to get a battery you need to know 3 things, how many Cold Cranking Amps your car requires, which side of the battery the posts are on, and which side the negative post is on.

The cold cranking amps are important. I've seen people say, "well it says my car requires 650, but i don't have power windows or locks or AC, so I'll be fine with 550 or 500 or whatever" In my experience this ends up bad, you've got to get the right battery or the car may not run right, or you may be replacing batteries regularly.

The posts are obviously important because of the cables. If you have tons of slack it may not be important, but I've never found anyone who had that much slack. Many cars don't even do when when the battery has those universal style top center terminals.

Just head down to your local autoparts store with a little info and you'll be fine.

[MichiganMat]

Optimas are heavy.

[Wil Ferch]

Optimas are heavy??

I guess its all relative....I replaced that HUGE ( MB Diesel size) original 88 Amp-hour size 49 battery in my 85 Carrera with a Red Top Optima...and the Optima is closer to the 66 Amp-hour size 48....must'a saved at least 10-15 lbs !! Simply used one of the other three hold down holes in the body of the car ( using, of course, a flat bottom plate that you need for the Optima).


---Wil

[speeder]

OK, here are the promised pictures. Ever heard the famous Vince Lombardi speech, "Gentlemen, this is a football".... ?

Well, this is a football. A small, kid's ball to be exact. It happened to be in my car when I installed the battery and needed to secure it, and it's been there ever since. Probably wouldn't pass tech at a PCA DE event, but between you and me and the tree over there, it works great in some high G-force situations, let's just say.

Also, the battery is an Auto Zone 47-D, about ~30 lbs. and $40.00. 590 CCA, more than enought here in SoCal. I originally had the biggest Delco made in there, approx. 50 lbs.

[Schrup]

I bought a Odessey PC680 off ebay for about $80 & fabricated my own bracket to secure it in my smugglers box.

[copper]

I ran into the same problem.

OEMs at my local Porsche dealer were $187 a piece. (Canadian)

I searched high and low, and studied the group numbers. These are important when trying to find one for the size for your box.

Measure your box, and compare the measurements to the specs of the group numbers.

For a listing of battery group number measurements, check here.
http://www.rtpnet.org/~teaa/bcigroup.html

Just one of many sites.

I found many suppliers listed specific replacements, (Most were group size 51R) but these were all an inch or more too big in all directions.

At any rate, I resorted to measuring the box and finding the closest fit.

The original Porsche batteries were 300 CCA batteries (X2).

I researched the Kirkland Signature (Costco) batteries and found them to be reliable and well reviewed.

Costco had a large selection and I was able to get a battery which was a very close match, but just a little too wide. To compensate, I simply turned the batteries sideways and slid them in with the negative (earthed) side in the box. The braided ground line still reached and they fit nicely.

Now I am running two new batteries with 620 CCA each, more than I'll ever need. I was able to use the existing clamp downs by securing them with flex ties.

I thought about the single battery conversion, but this is more work, and modifies the original weight balancing over the front fenders.

Best of all, the batteries were $50 each. (Canadian)

I can post pictures if you wish.

Jim

[Tony911Z]

Rennline had a slick installation kit (on display at GAF) to mount a smaller battery in the smugglers box.

[911nut]

I replaced the 60 lb. Optima with a 25 lb. Westco Miata battery and used a Pep Boys hold down. No issues so far.

[MichiganMat]

Originally posted by 911nut
I replaced the 60 lb. Optima with a 25 lb. Westco Miata battery and used a Pep Boys hold down. No issues so far.

See!!! I knew those Optimas were heavy. Long live my Westco!