Meares

i'm going to replace the Interstate battery(junk) with an optima agm one...do i have to hook up a booster or another car (like i'm jump starting it) to do this...sounds like a PITA

Meares

just googled the optima and they don't list porsche as a manufacturer they replace?! can i just find similar footprint and CCAs and install it?

Byprodriver

Optimas are smaller than oem battery. Optima works great but you have to do minor fabricating to mount it safely or maybe buy a mount. Not worth the hassle unless you really want to loose some weight up front.

Meares

ok...what brand? just don't like interstate

Macster

A few weeks ago I replaced the battery in my Turbo and did so so quickly the residual power/capacitance in the electrical system kept things "alive" the few moments the car was without power. I had no electrical systems on, all doors closed but of course the front trunk open.

I disconnected the dead battery as per the tech's instructions, lifted it out and set it down and then lifted the new battery up, positioned to and hooked up the leads as per the tech's instructions. Took about as long to do as to type in and I'm not a professional car repair/service tech, just an out of practice amateur.

When I took the car to the dealer to return the dead battery to qualify for the free replacement the tech double checked my work and fetched a proper vent hose/fitting for the new battery and fitted that for me.

While we were talking he mentioned that sometimes the loss of power can trigger a steering angle sensor error or some other error related to the loss of power but there were no warning lights on nor any error messages displayed on the dash.

I asked the tech about the ramifications of these possible errors and driving the car and the tech told me there were none and that just driving the car normally would have these dismissed anyhow and since none were in evidence I elected to just drive the car. The tech was right and everything was fine.

Now my car doesn't require any radio code but if yours does be sure you have this handy just in case.

Also, just to be safe I reset the window limits and went through the steps to calibrate the e-Gas.

Meares

sorry...mine's an '03 C2 coupe

fpb111

I also like AGM batteries better. They last longer with less hassle, no H2O to add, can't spill etc. The Braille battery either 48 (smaller) or 49 (uses last hole on 996 mount) will fit with no modifications.

From a Rennlist thread,

"Had to upgrade my battery after 2.5 years on Group 48 Replacement Battery - Rennlist Discussion Forums
I prefer AGM (Absorbed Glass Mat) Gel type batteries
I replaced an Interstate MTP-H7 With a Braille endurance series 7548 AGM battery - direct replacement.

Braille AGM B7548 battery group 48
BCI Group: [?]Group 48
Length:10.9" (277mm)
Width:6.8" (173mm)
Height (without posts):7.5" (191mm)

http://www.braillebattery.com/
http://www.braillebattery.com/index....durance_series

Battery sizes that fit 996 (group 49 will probably need a nut under the last, unthreaded, hole in the tray)

Group Interstate number Dimensions L x W x H Posts
48 MTP-H6 10-15/16 x 6-7/8 x 7-1/5 Top
94R MTP-H7 12-3/8 x 6-7/8 x 7-1/5 Top
49 MTP-H8 13-15/16 x 6-7/8 x 7-1/5 Top"

djantlive

go with a walmart everstart or sears diehard gold. both are good but walmart one is cheaper by about $50-60. sears warranty is longer.

interstate isn't good imo. i had two on my other cars and neither lasted too long.

Imo000

This got to be the longest battery swap I ever read.

Long Islander

If you want to install an Optima, you'll need an adapter. I have one that I'm no longer using. Send me a PM if you're interested.

Macster

I am working on a write up about replacing the struts in my Boxster's rear trunk. Better pull up a chair and a bag of popcorn.

Macster

My experience with Interstate batteries is not good either. The one installed May '11 failed just a few weeks ago and the one in the Boxster didn't last as long as the original battery that came in the Boxster.

fpb111

Not sure why you would have to hook up an aux power supply to change your battery?

I have had the battery disconnected/or out of my 03 C2 Cab five or six times for replacement or to work on the car. Most recently to replace the switch cluster when the turn signal switch broke.
The radio does not even lose presets. I think 01 (02?) and earlier radios are different and need radio code.

Meares

i thought i read somewhere that you're supposed to keep power to it...if you don't you have to reset the windows?? and set it back to "new delivery" mode or something like that

Kazual99

I've had my battery disconnected so many times I've lost count but well over 20 times. Absolutely no problems or CELs. Reset the auto up/down on the windows and all is good