Optima Battery - Cable replacement ?

To change over to the Optima Battery do you have to change the battery cables in a 1999 996 coupe ? I did a search and nobody answered this question.

I did not need extension cables when installing an Optima in my 99. You will need to find a way to hold it down though. The stock brackets will not work. Jim

I just replaced mine last week in my '99 also. No need to replace the cable(s) but they barely reach. Placement of the Optima battery (left to right) is critical for this reason. I just drilled some holes in the OEM tray for the new battery. I ran a drill through the flange holes in the battery also because they're small and not round (I think they were rectangular). On a side note, the Optima battery didn't feel that much lighter than stock. I think I heard about 15 pounds lighter. I didn't weigh them but it didn't feel that much lighter.

I understand that you don't need a longer cable if you use the "reverse post" group 34 red top (p/n (SC34R- used to be the orange top), which brings the positive terminal closer to the windshield. The reverse post one is harder to find, but any Interstate dealer should be able to get you one. Go to www.interstatebattery.com to do a zip code search. Let us know how you plan to install it.

I installed my Optima the same way Jakemate did and have no problems. No need for a cable extenstion either. Bobby

Bob, did you use the reverse post Optima or regular? Also, how did you mount the Optima?

I used the red top optima with the side and top posts. The wires were connected to the top posts with no problem. I removed the metal battery tray. Then I drilled a small hole into it. The optima has 2 holes in its base where you can insert a screw. I attached the battery to the tray with two screws and then reinstalled the tray with the original screws. Bobby

Thanks, Bob. I'm thinking of going with the method described by Dieters Motorsports, which involves making a flat plate onto which the Optima battery is bolted. The plate then mounts on the standard battery tray just like the original battery. I'm thinking of substituting ABS plastic for aluminum for the plate to make it easier to work with. If anyone knows where I can buy 1/4" ABS plastic, please post the info. For the instructions, go to the following: http://www.dietersmotorsports.com/tech/2002/02-2003.htm

Great info! Thanks Oggie

Just spoke with a plastics mf'er. They recommended high density polyethylene over ABS plastic. Supposed to be high strength and resistant to chemicals, etc. Also fairly inexpensive and easy to cut, sand and drill.

Yeah, i saw similar instructions elsewhere when installing my battery. Didn't have teh time or patience to make a mount but that is definately a more secure way to install the battery. I wouldn't worry about oils or spills from yoru battery because Optimas are sealed gel batteries. Bobby

Just installed the yellow top Optima without any mounting kit since: a> terminal cables seem to hold yellow beast firmly in place. b> plastic cover above battery seems to offer requisite (?) insulation from external elements. ANy safety issues here? Sri -------------------------------------- Alpine Silver/Black 2001 996 ex: Sky Blue/Black 1974 targa ex: Black/Black 1977 911T ex: Black/Black 1984 911 Cab

Not having the battery bolted down sounds like a bad idea. A minor collision or off road excursion could get the battery upside down on the battery tray.

I saw a mount specifically made for optima batteries in the performance products catalog. Its 75 bucks which i think is a little steep but may be a good solution if you don't want to drill. Bobby

Danny put a yellow top in his Boxster. Since he has amps and a lot of stereo stuff. Used the original cables and did not bolt it down. The cables provide so much tension I could not move it.

Same here, the cables provided much of the strength to hold the yellow Optima down. But... I did find out the cause of the battery drain. As it turns out I used windshield shades to protect the interiors as the car stood in the sun whilst the garage was being re-org'd. The factory alarm got confused and worked overtime draining the batteries. So, I had to trickle charge the OEM batteries and am returning the Optima. Sri -------------------------------------- Alpine Silver/Black 2001 996 ex: Sky Blue/Black 1974 targa ex: Black/Black 1977 911T ex: Black/Black 1984 911 Cab

What do you mean by "windshield shades?" Do you mean the sun visors? Could that really confuse the alarm?

yup, the sun visor covering the entire windshield. Having experimented with combinations of alarm on/off and observing the battery charge level am convinced of the cause. Sri -------------------------------------- Alpine Silver/Black 2001 996 ex: Sky Blue/Black 1974 targa ex: Black/Black 1977 911T ex: Black/Black 1984 911 Cab