Joe2000C4Cab

[I believe this is my 100'th post? Woo hoo!]

As part of my car's last visit to my indy mechanic, in additon to the brakes/rotors, they noticed my battery is weak. I've noticed it for a while now too. They wanted something close to $250 to replace it. Okay, I'm not that incompetent so I told them I'd do that one on my own. I know Eli@P will charge me $100 to watch him replace it but I'm up for the DIY on this one.

My rennlist search turned up the Optima battery as the best replacement in terms of cost and corrosion, however, there are some "home-made" parts necessary to complete the job (longer positive battery cable & mounting plate).

I passed on the machinist certification in lieu of an EE/CS degree so does anyone have spares (for sale) or know where I can get them?

Thanks!

SteveFromMN

I'm a EE and made my own battery hold down out of some tough plastic I had laying around.
The stock cables reached the Optima without modifaction on my 99 cab.

JayM

I replaced the Moll with a YellowTop Optima a couple of weeks ago. Rather than constructing a mounting plate from Lucite (or an aluminum billet like one guy did), I elected to make a template of the battery mounted in the desired position in the battery tray, then remove the tray, drill 4 holes through the tray, and bolt the battery to the tray. Since the Optima is smaller than the Moll, you can re-install the tray with the battery attached. My existing battery cables reached the terminals on the new battery, but it would not be a big job to put a longer one on if needed. The only parts needed were 4 #10 machine screws, some lock washers, and matching lock screws (the ones with the nylon inserts). I am sure there are those who will be shocked that I have violated the purity of the car by drilling into the battery tray, but in comparison to what I had done to the doors to fit the 3-way focals, this was nothing!
I am also in the Bay Area, so feel free to PM me if you want to follow up.

Tool Pants

http://www.renntech.org/forums/index...1834&hl=optima

I have been looking for someone in the San Jose area who wants to do this with the 34R red top battery. With the 34R you do not need to change either of the cables.

I would borrow your battery tray and have Tap Plastics make a mounting plate, then use the plate as a pattern for future installs. I would do it with my Boxster battery tray, but it is my only car, and I do not need a battery.

This is the yellow top one of the local owners has. No plate as the cables are so tight that they keep the battery from moving.

Joe2000C4Cab

Steve, Jay & ToolPants, thanks so much for the info (gotta love rennlist...)

ToolPants, I live near San Jose (I actually work near the SJ airport) and am interested in any help you might be willing to provide! I think in another thread you/someone? mentioned AutoZone in Santa Clara carries the Optima red top batteries? If so, I could buy one this weekend and we could set something up later? I'm more than willing to make it worth your time if you could help me... Name your brand of libation!

Thanks!

Tool Pants

There are different red tops. I suggest the 34R which originally had an orange top. The R means that the positive and negative terminals are reversed so they work with our cars with the oem battery cables. That is why Optima originally made it with an orange top, because it was to distinguish it from the other red top batteries.

Costco does not have a 34R. I have never seen a 34R at AutoZone, but they might be able to order it for you. If you do a google search you will find plenty internet companies that sell it. Also search on ebay for Optima 34R and you will find them.

I set up work on cars days in San Jose on renntech.org in the section for that.

Chrisp3

" would borrow your battery tray and have Tap Plastics make a mounting plate, then use the plate as a pattern for future installs. I would do it with my Boxster battery tray, but it is my only car, and I do not need a battery."

ToolPants--"If you do not need a battery"....how do you start your car and keep all the electrics running? Are you using BATCAPS or something?

Joe2000C4Cab

Hi ToolPants,

Well, I called AutoZone in SantaClara about the 34R and they said they have it in stock. But when I went there this afternoon, they did not. So, if anyone calls them, don't believe them.

I just ordered a 34R online from AJUSA (rennlist sponsor). When I receive it, I'll hook up with one of the renntech.org work days.

One question, should I go to TapPlastics ahead of time?

Thanks!

Tool Pants

For Chrisp, I meant that I do not need a replacement battery.

For Joe, 2 years ago when I did need a battery I pulled the tray out to measure it for an adapter plate. It would be 3/8" thick. 6 7/8" wide.

There are 4 holes in the tray but only 3 are for the clamp as the 4th hole is for drainage. When I measured I assumed using the 2nd hole which meant the length of the plate would be 10 7/8".

For some crazy reason I would like to use the 3rd hole instead and would have to remeasure to get the exact length,, but from looking at my pictures it would be about 12 1/4". The length of the 34R is 10" and I was thinking of centering it in the tray whereas the oem battery is off to one side. If I have time I could pull my battery and get the exact length.

I was thinking of black ABS plastic. Tap Plastics on The Alameda has a scrap bin you might want to check but scrap is usually not big enough.

JimB

Here's another alternative that works for me. Just pull out the base plate, add the rods and run a alum strap across the top. Not as pretty as Tool's version but it holds the battery very securely and it's easy to get it in and out.
Jim

Mr. C4

Gotta love those Swedish high quality Optimas!

Ciao,

Johannes E.

SteveFromMN

Here is a pic of what I did. The battery is the red top 34R. I slid it all the way to the drivers side of the tray. Stock cables work. The other wires you see are Ham Radio and Porsche HP Audio connections. I made the hold down out of some tough plastic I had. I don't know what it is but it is machinable and tough. I fastened my old hold down on the tray also so I would not lose it if I wanted to go back to the stock battery. It serves no purpose for now except I know I won't lose it. Putting an Optima battery in a 996 is easy. I got mine at Batteries Plus. They also carried the stock battery for my wife's Mercedes at a fraction of dealer price.

Tool Pants

I like that idea of making a battery clamp out of a piece of plastic. I have a table saw and a router. It looks like the 34R has a lip at the bottom that sticks out past the case so the plastic clamp can hold it down, just like the metal clamp does with the oem battery. I also assume you got the correct metric bolt and bolted the plastic clamp to the tray into one of the existing threaded holes. Does the 34R have a lip on the drivers side so that it is help down by the edge of the battery tray.

But your set up is like the oem battery - the battery weight is not centered in the middle of the car and you need to do a corner balance.

But I guess the handling will be ok because you have the dead weight of the unused metal clamp on the other side of the battery.

SteveFromMN

The weight thing is not a problem because I have a big lead dummy I put in the passenger seat.
It also helps to go in the high occupancy lanes.
Yes the 34R or R34 I'm not sure which has the lips you describe. There are a number of tapped holes in the battery tray. So yes I just got a new metric bolt and I think I just ground an angle on the plastic piece with a bench sander to match the battery. The OEM clamp down was not quite the right length to work.

Joe2000C4Cab

Whew, lots of good info here...

First off JimB, aluminum is a conductor. Is there any concern that your strap will cause a short between the terminals, if not under normal operating circumstances but maybe how you (obviously) use the car?

Steve, trick setup. When my battery arrives, I'm sure I'll have more questions.

ToolPants, do you think it's possible to change Steve's setup such that the battery is dead center in the car? Or, because it's like the OEM install, it's really no different? I have had my car precisely aligned - they even asked me my weight.... so I wouldn't want the new battery to screw things up for me.

Again, thanks for all the great info everyone!