Dead battery dilemma, need advice

Apparently my valet at my condo left the key in my ignition which drained the battery completely dead. It has been dead for 2 days now. I tried the Emergency Front Hood Release through the fuse box from the manual but even that won't work because the battery is completely drained. The problem I have now is: 1) completely dead battery 2) cannot open the front hood to access the battery to recharge(?) or replace with new one 3) car is stuck in my underground condo garage and tow truck cannot get to it Any solutions? I need a way to open the front hood so I can replace the battery myself. But Porsche Roadside Assistance says that you cannot replace the battery yourself cause it'll cause some computer problems--can someone verify this? Manhattan Motorcars says $380 for a new battery, and $175 for initial diagnosis to open the hood :hilarious: I want to avoid this even though the condo will pay for it. Please give me some advice..

First, the fuse box jumper should work even if you have a completely dead battery (or no battery for that matter - I know because I've tested it). Are you sure you hooked up the pos. to the jumper terminal and the neg. to a suitable ground on the car (like the door latch)? You do have to activate the front hood release once you have your jumper battery attached. If for some reason that still doesn't work, then there is a manual release inside the left fender liner. To get to it, it is easier if you can remove your left front wheel, but apparently people have managed to get to it with the wheel in place. See this post: http://www.planet-9.com/cayman-boxs...xster-electronics/37495-dead-battery-key-stuck-tried-everything.html#post403333 Finally, I switch back and forth between my OEM and track battery all the time without any "computer problems" - you do get a PSM warning which goes out after you drive a few yards, and you have to reset your clock. I just replaced my 4 year old OEM battery (myself) with an Evermaxx from Walmart for $80.

Thanks for the response. Unfortunately the fuse box jumper method isn't working for some reason. Could this mean there is a deeper problem? Or maybe a fuse broke that I have to replace first? I'm going to look for the latch tomorrow..glad to hear I can swap the battery without spending $600

Quotes source post: 403333

Is there a 3rd way? I'm not sure if I am able to remove the wheel in my condo garage.

If your car is a manual, you could put it in neutral and push it to a location where you can jack it up. or tow it to the entrance of the garage. With tiptronic, if you can get it in neutral, the same should apply. Just don't let it roll into anything.

3rd solution. Get a portable battery jumper from a Sears or Home Depot. Now here is the rough part, find a male to male 12V battery plug or find a battery jumper that provides a 12V plug. Put this into the 12 v power connector in the passenger footwell and attempt to pop the hood using this path. You may be able to get away with splicing two 12v connectors together. Hope this makes sense, some of this stuff could be hard to find in NYC, no one has a car!

Pete's idea is a good one also - some of the portable jumper batteries actually come with a 12v plug which might allow you to get enough power to open the front hood, if not start the car (I believe someone recently confirmed this with their dead battery). Also, do not assume that you automatically need a new battery - you may be able to fully recharge it again. You can take it to a place like Autozone, where they can recharge and test it for you. AAA also provides that with their mobile service where we live.

Roadside Assistance is telling me the Porsche Manual instructions are wrong. The manual says the negative has to be on the door latch but it should be on the middle door hinge. The door latch is insulated and will not work as a ground. btw KS-CS, you're right, the Roadside Assistance guy confirms the Fuse Box method should work even with a completely dead battery. That method bypasses the circuit. A Porsche technician is on her way now.. Hope this works...........

Fixed! make sure the (-)ground is on the middle door hinge (the unpainted one) Pretty disappointed in Porsche with how problematic a simple dead battery is to fix and even more disappointed at the error in the manual.. Live and learn.

Glad you got it open - let us know what you do about the battery.

Glad you got it open. I was going to ask how you could get the wheel of if you can't get into the frunk to get the wheel nut key. Moot point.

thanks for all the input guys, hopefully this thread will save someone a lot of stress in the future....

I'll be on the lookout for a white Cayman in the city this weekend!

Better put that in the glove box. That's why I put the booster cables under the passenger seat.

My dad's '09 Cayman just had the battery die on it. I've been tryin' to get it fixed for him, since he's in Afghanistan. I noticed the booklet says to attach the ground to the door latch for my '07 Cayman , but his says to attach to the hinge. I tried it both ways, and I couldn't get the lid to pop. I also tried a set of booster cables that plug into the cigarette lighters (12V), and that didn't work either. Someone from the local dealership is gonna make a trip out to his house on either Monday or Tuesday to try take care of it.

I'm not sure why it seems so many people have difficulty with this. You have to make sure that you have good metal-metal contact on the red jumper which you pull out in the fuse box, and attach the negative lead to a suitable ground (unpainted hinge, bolt, or door latch); then use the front hood release in the door sill (not your key remote) to open the hood.

Maybe that's where I went wrong. I used a charger that I've used for other vehicles to get them goin'. I didn't try a battery. I'll have to try that. Thanks.

Yes, I don't think that you can rely on a battery charger to work - the smart chargers usually test the battery before charging; if you just hook the charger to the fuse panel jumper, it won't find a battery to charge, so it probably won't deliver any current to the jumper. The jumper actuates the front hood release servo directly, and doesn't go through the battery.

My regular charger, connected to red pull-out contact and unpainted door latch, has always worked for me.

Cayman -S sat in the garage for most of Covid-19. Battery died once or twice so I decided to leave the Frunk latch popped (secure garage in my building). HOWEVER, some kind-hearted do-good neighbor PRESSED THE LID SHUT!!!! NOOooooooooooo!!! Locked out of battery compartment (also lug-nut socket and other essential tools) for months. I've tried each of three methods in sequential order. 1. Standard jumper cable / maintainer approach. Clamp positive to the red post in Fuse Box. Bingo. Works every time. Unless, as in my case, your dead-*** battery is totally oxidized and so you cannot close the circuit to apply voltage. 2. MANUAL cable pull. Hidden beneath driver-side fender liner up and inside of the headlamp on the frunk sidewall. Fender liner is a bit of an inconvenience to remove especially if your JACK and LUG NUT SOCKET are locked in your Friggin Frunk! It's a thin gage braided cord with a little nib on the end (see pics). Difficult to find, harder still to pull (yank) and successfully release the lever (they should have added a crimped loop on this, something you can actually pull on with your hand or a hook). In my case, the cable had been drawn in from the within the frunk, such that the nib on the end was pulled tight into this rubber grommet. My angled needle-nose pliers could not get a grip on this small bit (very awkward position and angle). 3. WINNER! DO NOT ATTEMPT #2. Apply 12vdc to fuse A3, bottom post to energize that circuit, then pop the electric release as usual. DONE. Fuse position A3 says its rear control and rear lid release but same circuit as front lid release. Use a Bussmann type blade fuse tap on the lower blade, re-insert the fuse, use small alligator clip attached to jumper cables (or lithium-ion battery). There are two types of blade fuse taps. One has a slot so the blade tab passed through it. The other type is bent around the inserted end of the blade tab which makes it wider, tough to re-insert (press hard enough and it will fully insert). Yellow Cayman pic courtesy of Andy Willis - 996 Register Secretary [email removed]

Excellent trick. Thanks for sharing.

Good trick! Would be nice to post a photo of the tapped fuse.

Mine sat in my airplane hangar during some severe storms. Yep, long enogh to drain the battery. The post in the fuse box was pushed in, so I could not connect to it. Lug wrench and locking bolt socket in the frunk. I got a cigarette lighter plug with wires on it. Replaced the fuse with a piece of brass rod cut to length creating a no-blow fuse. Plugged in the lighter plug and measured the voltage polarity on the two wires. Connected a battery charger to the lighter plug and popped the frunk with the switch by the driver's seat. If you happen to reverse the polarity by accident, the fuse at A3 will blow (ask me how I know) and no damage will occur. The trusty lighter plug and socket for the lug bolt are now in the compartment behind the driver's seat.

Unfortunately I let the battery go completely dead on my 2008 Cayman S …i have tried to use the brass connector in the drivers side fuse box, connected to a battery, to give me enough juice to pop the phrunk. Nope. I moved the cable connectors around a bit and could hear the fuse box making a static-ee ticking sound…but it will not pop the front or back hatches. I am not sure what to do next other than having a tow truck take it to my mechanic to do. No use lamenting the poor decision of me letting the battery die or Porsche not having a smarter way to open a “dead” car. Any help would be appreciated. g

thanks. I appreciate it. Not in a position to pull the wheel off. I am not much of a mechanic on any level. Using the battery and fuse box to attempt to open the front was about the limits of my ability. Do newer Caymans have this same issue?

At least on a 987.2 you need to use the key fob to open the frunk after you connect the fuse box connection (not the switch by the drivers seat). Not sure on the 2008 but check the owners manual. If that doesn't work, you are most likely not using a strong enough "source" or your ground connection isn't good. Try attaching to the door arrest strap.

When I went through this exact nightmare scenario on my 2008 Cayman, I tried all of the described options to open the frunk after a totally dead battery. Fortunately, I had left the doors unlocked and so the window was slightly down allowing the key to open the door without hanging up on the glass. I first tried a jump pack on the fuse block tab.....I turned the key to 'ON' and saw power at the accessories. However, this didn't work (a dozen different times) when trying the latch release along the door sill. Of course, I couldn't remove the wheel because the wheel lock key was in the frunk. But I was able to turn the wheel enough to get partial access to the wheel liner and ultimately the emergency cable release....unfortunately, the cable is so short that with only partial access I could not pull it (using vise grips) with enough force to get the latch to open (the cable is a thin steel cable with no grab point on the end). After returning to the fuse block and 12v jump pack (after 3 days of frustration) I connected it and decided to try the key's remote frunk release and after clicking it about 6 times........voila.....the frunk opened. Hurray!! The battery was removed and replaced without any problems. In the future, I plan on extending the emergency cable, adding a pull handle and possibly putting it through the cabin wall to the interior near the fuse block. At the very least, the wheel key will be relocated to the cabin interior where it can be accessed even with a dead battery. Porsche took vehicle security one step too far in this case.

Wow. This made me think! I have always had battery "tenders" on my toys but now I am thinking about where to put the leads to connect to it. Looks like the trunks are not a good place, but somewhere with outside access. Sorry you had to go through that but a great lesson. Thank you.

I think somebody needs to invent a small waterproof pull upgrade that will easily open the trunk from the passenger side wheel well. How hard could that be?

I appreciate everyone contributing to this dead battery issue. I commiserate with you after my own experience. I personally understand much better with videos and or included images. Language alone can be imprecise making it more difficult for me. I was fortunate to find a youtube video that gave step by step illustration on how to jump a dead battery from the fuse panel. I would post a link, but sadly I haven't figured how (sigh). Here it is under it's title. From Pcarwhisperer Is your porsche dead? How to jump start a cayman or boxter! (even when the hood isn't open!) This solved my immediate frustration being unable to access the battery through the frunk. Turns out the negative battery post clamp was not providing enough contact. Hope this helps someone.