Long Islander

Note: Part numbers sometimes change without notice. Always double check with your supplier that you have the latest part numbers. These instructions show how to install an Optima Group 34R battery in your Porsche Boxster or 996 using a plastic adapter plate. The cost of the materials (other than the Optima battery) should be under $20, and an hour or two of your time. You don't need to make any modifications to your car or to the Optima battery. All you need to do is to make an installation plate out of plastic, and then bolt the Optima battery to the plastic plate, and the plastic plate onto the original Porsche battery tray just like the original battery. Once the Optima battery is installed, you can easily remove it and re-install the original Porsche battery within a few minutes. Optima makes a great battery, but only in a limited number of sizes, none of which is an exact fit for a Porsche Boxster or 996. The Optima Group 34 battery is shorter (by about 2") and slightly taller than the standard group 91 battery found in most Boxsters and 996s. To install an Optima battery, you need to make adapter plate out of plastic. Dieters Motorsports (www.dietersmotorsports.com) has detailed instructions on how to install an Optima battery using a 1/4" thick aluminum plate and a longer positive battery cable. I thought Dieters Motorsports had a great idea, but it requires an aluminum plate to be custom-made by a machine shop and a longer positive battery cable. I asked a couple of machine shops about the cost of a piece of aluminum, and they quoted me between $130 and $190. I found that high-density polyethylene would be a great substitute and is very easy to cut and drill into, so you need to only buy a flat sheet of the polyethylene and do the drilling and cutting yourself. It is black with a wrinkled finish, so it looks like a lot of other plastic pieces that came with the car. I also found that 3/8" thickness works better because it fits more tightly under the tabs on the rear and driver's side of the Porsche battery tray. High-density polyethylene is both very rigid and very light, yet also resistant to battery acid (in case your old battery already spilled acid onto the battery tray). My installation enabled me to install an Optima Group 34R without replacing any battery cables. "R" stands for reversed positive and negative posts, which puts the positive post closer to the end of the positive cable. With the Group 34R, both cables just barely made it on my car (2001 911 C2). Had I used the regular Group 34 battery rather than the reversed-post group 34 battery, I'm not sure whether the cables would have been long to reach the battery posts. Other 996 owners have reported using a regular group 34 without having to replace any battery cables. In any event, the price of the Group 34 and 34R is the same - it's just that the 34R is a bit harder to find. I bought mine for $119 from an Interstate Battery distributor, who had several in stock. All Interstate Battery dealers carry Optima batteries, and practically every gas station in my area is an Interstate dealer, so you should be able to buy the 34R very easily no matter where you live. Interstate's web site (www.interstatebattery.com) allows you to do a zip code search for the nearest dealers. Materials Required: 3/8" high-density polyethylene: You will need a piece of 3/8" thick high density polyethylene, cut to 14 X 6-7/8". I used 14" X 6-3/4" because it was readily available, but the footprint of the Porsche battery is exactly 6-7/8" wide, so you would be better off with that size (I'm not sure 7" will fit, so you should check your battery tray width to see if it can accommodate a 7" wide plate). The 3/8" thickness was just right. A half inch thick piece would not have fit under the edges of the battery tray,and 1/4" would not be tight enough under the edges to prevent the battery and adapter plate from bouncing up and down. Also, 3/8" was thick enough to make the adapter plate very rigid. Locating a plastics manufacturer to sell you a small piece of polyethylene may prove to be a challenge. I was lucky as PlasTEAK (www.plasteak.com) happened to have just such a piece laying around, which they sold to me for $10. I also found that K-Mac Plastics (www.pbt-plastic-resin.com) will cut to size, but they may have a minimum order size. Otherwise,you can check your local yellow pages under "Plastics" and arts and crafts stores. Stainless steel hardware: I bought all the necessary nuts, bolts and washers for around $5 from West Marine. A good hardware store may have these as well. West Marine did not have 1-1/4" long screws of the type needed, so I bought 1-1/2" ones and cut them down with a hack saw. - four #10, phillips, flat head, 1-1/4" long screws - four flat washers 5/8" diameter (needs to fit over the #10 screws) - four #10 locking washers - four #10 cap nuts. Initial Preparation of Adapter Plate: 1. Using 1-1/2" (or wider) masking tape, tape all four edges of the adapter plate. This is so that you can easily see the drilling and cutting marks on the plate, which otherwise would be hard to mark and see on the black plastic. 2. Mark a 1/2" by 1/2" square at two of the short sides of the adapter plate, and cut away these squares. The diagram to the left shows in black the squares to be cut away. Adapter plate next to the Porsche battery tray after the holes have been drilled. 3. Take the adapter plate to the car. 4. Bring a skinny pen with you (I used a ball-point refill from a Cross pen so that my marks would be as precise as possible). Removing battery from car: 1. If you have a battery maintainer or trickle charger that plugs into the cigarette lighter, plug that in, as it will eliminate the need to re-program all your radio settings. 2. Open the front hood, and remove the battery compartment cover by turning the two thumb-screws and lifting out. You will now see the battery. Since you will need to stand in the front trunk, you may want to put down a towel or drop cloth to keep the trunk floor clean. 3. Standing in the trunk, remove the negative terminal cable. Next remove the positive terminal cable from the battery and wrap it in a towel. Finally, disconnect the vent tube and curl it up and place it out of the way (you won't be using this anymore). Move the positive and negative cables out of the way. Handle the positive cable especially carefully (i.e., don't let it touch any metal) if you have your car hooked up to a trickle charger. 4. Unbolt the battery hold-down clamp and set aside the bolt and the clamp. 5. Remove the battery by moving it forward and slightly to the passenger side. 6. Loosen bolt at the other end of the negative cable (the side farthest from the side that attaches to the battery) a bit so that the cable swivels easily. Follow the positive battery cable back to where it enters the car. You will notice a round black plastic cap that covers the other end. Pull this toward you with your hand, and underneath you will notice a nut. Loosen this with a socket wrench. If your car is connected to a battery charger at this time, be careful not to touch any metal while loosening the nut. Loosen the nut so that there is some freedom of movement at the end of the cable. 7. Don't unbolt the battery tray just yet. Marking Optima Battery Location in Car: 1. Place the plastic battery adapter plate inside the battery tray and position it all the way to the back and to the driver's side. Make sure it is pushed all the way in. 2. Take the Optima battery and place it on the adapter plate, with the positive terminal to the passenger side. Make sure the adapter plate did not move around when you put the battery in place. If so, push the adapter plate toward the back and driver's side again. Push the Optima battery all the way to the back. 3. Move the battery toward the passenger side of the car just enough so that the positive cable fits over the positive terminal of the battery. Move the battery to the driver's side while removing the slack from the positive cable. Don't tighten the positive cable to the post. Swivel the negative cable and stretch it so that it reaches the negative battery post and fit it over the negative terminal. Make sure your battery tray is pushed as far to the rear of the car and as far to the driver's side as possible. Make sure you can still remove both battery cables without having to move the battery around. 4. Using your skinny pen, mark all around the edges of the battery. 5. Remove the battery cables (remember to wrap the positive cable in a towel again). 6. Remove the battery from the car. 7. Remove the battery tray from the car, by unbolting the four nuts that hold it in place. Drilling Holes in the Adapter Plate: 1. Take the adapter plate and Optima battery to your workbench. 2. Measure the distance from the left side (passenger side) of the battery tray to the center of the bolt hole for the hold-down that holds the original battery in place (this should be the third hole from the right, or driver's side). 3. Place the adapter plate inside the Porsche battery tray, making sure you push it all the way to the right and rear of the battery tray. Mark the location for the hole in the adapter plate that is equal to the distance you just measured. 4. Drill a hole in the adapter plate that is wide enough to accommodate the original bolt. 5. Once the hole is drilled, test to make sure the adapter plate bolts into the Porsche battery tray. Note: you will not use the battery hold-down with the Optima battery, just the bolt. 6. Take the adapter plate out of the battery tray and place the Optima battery on top of the adapter plate, using the marks that you made to properly locate it on the plate. 7. Take one of your stainless steel flat washers and locate it above one of the holes on the bottom of the Optima battery. Center two of the washers over the holes on one side of the battery, and mark with your skinny pen the exact center of the hole on the battery plate. Before you mark the other side, you may want to drill the holes on one side and bolt the battery to the mounting plate (I drilled all four holes first, and found they didn't all line up, so I spent a lot of time making the holes larger to make them all line up). 8. If you use a 5/32" drill bit, the screws will actually thread their way through the plastic. If you want them to slide through, use a larger bit (maybe a 3/16" bit). You will also have to countersink the flat head screws so they are flush with the bottom of the plastic plate. If you don't have a countersinking drill bit, you will need to use a drill bit as large as the head of the screw, and then drill into the center of the small hole just deep enough to get the screw head not to protrude. This takes some patience and may take a few tries to get it just right. 9. Bolt one side of the battery down (positive side away from the notched edge), then repeat the marking and drilling process. 10. Bolt the battery to the adapter plate. At left is a photo of the battery bolted to the adapter plate. 11. You're now ready to bolt the battery tray into car Back to the Car: 1. Take the Porsche battery tray, Optima battery (already bolted to the adapter plate) and battery tray back to the car. 2. Bolt the Porsche battery tray back into the car. 3. Place the adapter plate with Optima battery bolted to it into the battery tray, and bolt it down with the original bolt that was previously used to bolt the hold-down clamp over the original battery. You will not use the hold-down clamp, but hold onto it in case you need it in the future. 4. Connect the positive cable to the positive terminal and tighten. 5. Tighten up the other end of the positive cable, and snap the plastic cap back over the end nut. 6. Connect the negative cable to the negative terminal and tighten, then tighten the other end of the negative cable. 7. As you can see from the photo to the left, I removed the carrying handle for the Optima battery. To do this, raise one end of the handle as high as it will go and then lower the end until you can slide it past the groove that holds it in, then out. Then slide the other end of the carrying handle out.