Engineers and complexity, a cautionary tale

This is a story about overly complex engineering, subsection: German, sub-subsection: sports cars. 

As they eventually do, the battery died in my 911 (997.1) sometime in the last couple of weeks. Not just too weak to start the car - stone dead, no interior lights, nichts. I've had the car for >5 years, and I suspect the battery wasn't new when I got it, so it was due, and the car was in my garage, so it's not like it stranded me or anything. But there's still the matter of the battery replacement to deal with. And that, my friends, is a funny story.

As you may be aware, the 911 is a rear-engine vehicle, but the battery is still up front, in the "frunk".

The battery is under that Porsche logo near the windshield washers

Because it's a trunk, and not a hood, it has an electric release, so that it can be opened via a button on the key from outside of the car in addition to the switch in the driver's door sill. 

Betcha you can guess where this is going... Surely the brilliant engineering minds at Porsche wouldn't leave you with no way open the trunk to access a dead battery? Of course not, but being Germans, and fans of both demonstrating their own engineering prowess and overly complex solutions to relatively simple problems, Porsche forgoes the Occam's Razor solution of an auxiliary cable-actuated release somewhere in the car. Well, that's not entirely true - there's apparently one for if you're really stuck, like if the electric release actuator fails, but it requires jacking up the car (remember, jack and wrench are in the trunk you can't get into), and removing the left front wheel and inner fender liner. Also there is an electric release for the engine cover hatch, so there's no point in putting an auxiliary set of terminals back there for jump starting the way some cars with the battery in a weird location have. I suppose in theory you could try to backfeed through one of the cigarette lighters, but those have fairly weak fuses (I've blown them more than once using the factory-supplied 12V air compressor for longer than a few minutes, so I'm not sure.

No, Porsche has an "ingenious solution" to this problem. And there is a procedure which must be followed, that you are completely familiar with because you've carefully read and understood your entire operator's manual, ja? 

Owners Manual

Assuming that you are starting with a locked car:

1. Manually unlock the driver's door with the key.
2. Locate and remove the access cover for the fuse panel in the driver's footwell. (No interior lights means it's going to be dark under the dash, have fun with that.)
3. Locate a red plastic bit with a picture of a car with the hood up in the upper right corner of the fuse panel (i.e. the part furthest away from the door). It will be pushed in far enough that you can't actually grab it with your fingers, so use the small metal tool attached to the back of the fuse panel cover to catch and pull this plastic bit so that it sticks out of the fuse panel. 
4. Source a set of jumper cables and what Porsche's manual refers to as a "donor battery". Yes, it can be attached to another vehicle, but the manual has pictures of it just being a spare battery you happen to have lying around.
5. Connect the positive jumper cable to the now-exposed metal contacts on the red bit in the fuse panel.
6. Connect the negative jumper cable to the door latch. Note that because you opened the car without disarming the alarm via the keyless entry, the alarm will immediately sound. So you're going to be rooting around under the dashboard of a Porsche, while the alarm goes off. Nope, not trying to steal the car, honest! 
7. Pressing the trunk release button on the key will disable and silence the alarm, and open the trunk, after which you can disconnect the cables and access the battery as needed.

Other important notes: This does not provide enough power to jump start the car, nor will it run anything else in the electrical system. It is only to power the modules that run the keyless entry RF receiver and the trunk actuator. I know this because I tried 3 or 4 times to open the trunk via the switch right next to me in the driver's door sill, which does not work. Additionally, the ignition switch in these cars is all electronic. When you turn the key to any position, it returns to the original position once you release it, so there is a mechanical catch that keeps you from removing the key when the ignition is on. When the battery is dead, it fails closed, so if you insert the key and turn it without realizing the battery is dead like I did today, it latches on your key but does not have any power to release, meaning your key is now stuck in the ignition (though it did release my key when I applied power to the terminals for the third time). When the key is in the ignition, the buttons on the key don't seem to work, so I had to go get my other key to actually open the trunk.

That red bit hiding under the 404 on the top right is what you're looking for

So now we have access to the battery, but there's still some fun to be had. The battery is in the very center of the car, and the hood trunk opens toward the windshield, meaning that even with the hood open, there's not a lot of clearance near where the battery is. 

still a long reach from the side

Faced with several equally bad options for how to remove the 53 lb (~25 kg) battery by myself, I ended up standing in the trunk, still bent over to avoid smacking my head against the hood, but much closer to the battery and thus with a much shorter lever length than if I'd tried to do it from either side or the front of the car. I ended up basically deadlifting it like a kettlebell since it had a set of handles in the center. Installation is, as Chiltons is fond of saying, the reverse of removal, and thus equally awkward. I'm also not sure that there is any particularly easy way to do this as a team lift either. A friend joked that there's probably some $3000 Porsche tool to make this process easier. It's a wonder I didn't hurt my back.

If there's any moral to this story, it's a cautionary tale on dismissing the simplest solution, and it's based on some experiences I've had troubleshooting networking and computer issues, where my predecessors or vendors were enamored with solutions that were too cute by half because it showed how smart they were, and basically failed the 2AM test*, or violated the principle of least astonishment, or both. 


*The 2AM test is a test of complexity and ease of understanding: simply, whether you, as someone who didn't design it originally, can figure out the problem and fix it when it wakes you up out of a good dream at 2AM because it's broken.