Battery Dead

[jakkay968911]

As I approached my 2005 Carrera with key in hand I realized the remote door opener was not opening the door. I used the key manually to get the door opened and noticed the interior courtesy lights were not illuminating. The obvious conclusion was that the battery was dead (after only sitting two days) but I tried to start the car anyway. The key turned in the ignition in the usual manner, but no starter motor response. That's when I discovered that the key wouldn't release from the ignition switch. I was able to find the positive jumping contact in the fuse panel to hook up the cables to open the front trunk and expose the battery. My Porsche is parked in a tight one car garage and I had to run two sets of jumper cables to reach the fuse panel area. I also jumped the trunk lid open from a car that was not running and everything worked out fine. The question I have is if I could use a battery trickle charger to jump the lid open. That would be easier since the distance to make the contacts would be shorter. I have a 2/10 amp charger that also has a boost feature. I am concerned that the trickle charger could damage the electrical system if used on the higher settings. Would the 2 amp setting provide enough current to get the trunk lid open without causing any damage or should I try the 10 amp setting.

After hooking up the jumper cables to a running at idle 2004 Honda Accord, my car started about 20 minutes later. I was hoping it would start sooner, but apparently my battery was totally discharged. The ignition key did release once the jumper cables were connected to the running vehicle battery. I was hoping that the Honda had a compatible electrical system and the voltage ratings were also compatible.

Upon starting my car, I drove five minutes to the closest mechanic shop. They checked the battery and alternator output and said eveything was normal and gave me a print out of their findings. I am certainly apprehensive at this point to drive the car at all, but the past three days I've had no problems. Any advice would be much appreciated regarding the use of the trickle charger to open the front trunk lid.

Thank you,

JK

[PAULSPEED]

You may just want to invest in a jumper battery.

You could also drive the car more but then

the roads might be snowed in Chicago.

Paul

[jakkay968911]

Thank you for the reply Paul. The jumper battery might be the way to go. I was tring to avoid getting one if I could use the trickle charger on the 2 amp setting and then the 10 amp or the boost setting to charge the battery and/or start the car once I got the front trunk lid open. Once the snow starts I probably won't be driving it much. I do miss the ammeter guage I had on my 996. Seems it was replaced with an oil temperature guage on the 997. My biggest concern is having the battery die and the car not start when I am out somewhere away from home.

[mxt_77]

Are you confident that you didn't leave an interior light on or something? If the battery tests good and the charging system tests good, then it seems entirely possible that there was a current draw over the 2 days that it was parked that pulled the battery down. This would even seem more likely if you hadn't noticed any other symptoms before or after this incident (slow starts, headlights dimming when the a/c or other accessories come on, etc).

[logray]

Interesting they found the battery condition OK, if this is an original battery, 7 years is pretty long for any battery (although the original MOLS battery that was in my 996 lasted about 8 years before it crapped out).

I'm wondering if the battery is marginal and even though it passes a short test, perhaps it is marginal?

As for the trickle charger, this one comes highly recommended by just about everyone and as an added bonus RT.org gets some of the profit if you buy it through the store:

http://astore.amazon...tail/B001684YCK

Edited November 14, 2011 by logray

[Cassiebox]

re: maintainers...

unless RT.org gets $50 from the purchase, which I doubt, why not make a $25 contribution to RT.org and then just pick up the CTEK original version (CTEK 3300) - $57 here and the $12.54 cig plug here. RT will get more and you'll still save $25 even after contribution and have more connection options.

Good luck :)

Edited November 14, 2011 by Cassiebox

[jakkay968911]

Thanks for the response. The battery is an Interstate, and fits the battery compartment in size like the original Porsche battery, but I don't know the specs or how old it might be. It looks like it might be new in fact, fresh and clean and so are the contact posts. I know there weren't any visible accesories on when I left the car in the garage, unless something I couldn't see was on like the glove box light or front trunk light. I think I need a second opinion on the battery and charging system condition. I appreciate all the information and advice, thanks again.

JK

[logray]

If the battery is a more than a couple years old and does show any signs of weakness, depending on how many years it is rated to last, it might be cheaper just to replace... wallymart, autozone, costco are all places you can get a cheap battery.

Regardless though I highly recommend a battery tender if it is going to be stored for any period of time, say longer than 2 or 3 weeks without starting it.

[jakkay968911]

I am trying to determine if there might be an unusually high current draw after shutting off the car before I get a new battery. There are so many posibilities I guess, I hate to replace something that is OK and then have the same problem. Meanwhile I have to take precautions and prepare for it to happen again. Not getting much peace of mind though. I could understand the car not starting after 2 or three weeks, but only a couple days makes me apprehensive to drive it. Thanks again for all the input, thoughts, and advice.

JK

[PAULSPEED]

I would dis-connect the battery during the snow. Use

the manual key to open the car. Use the jump battery

to plug into a cig. lighter to open the trunk.

Re-connect the battery and use the jumper if you need.

Good luck.

Paul

[jakkay968911]

Thank you Paul, I might have to do as you suggest. I was trying to avoid the convenience compromise if possible. I drove my 2001 996 through three Chicago Winters, commuting daily with no problems at all and I was expecting the same reliability from the 997. It seems there is a general weakness in the charging/starting/electrical system of the 997, unless my car is the only one with such problems. Now I discovered that I can't find all season tires in the 19 inch 295 series for the rear so it may be sitting in the garage for most of the Winter anyway. I had the 18 inch 265 series on the rear of the 996 and the Michilen A/S Sports worked out great. I can always go the two sets of tires/wheels route but am planning to avoid that.

[PAULSPEED]

I have a couple of jumper batteries.

They work great in a plane. One

powers my moving map display while

flying.

Good luck with your winter shut down.

Paul

[dphatch]

5 years is pushing the useful life of these batteries and while there is always the occasional exception ( 6 to forever years ) the rule is 5 maybe 6 years is all you get from the batteries in these cars. Get a new battery and a trickle charger. I use the CTEK but just be aware that if you have a power outage the CTEK will not restart itself and will need to be reset in order to work. If you are going to leave the car unattended for long periods of time the CTEK would not be my choice.

[SA321]

random bits of info:

CTEK on a fully discharged battery will show that the battery is almost fully charged (not sure how it is possible but it is the case).

it is sufficient to open trunk.

with a discharged battery my car (996 C4s) after i try to turn ignition on locks out completely and plays dead with no lights on dash even if another battery is connected. once i disconnect and connect back my discharged battery and an external one i can start the car.

[Rayvan986]

The service advisor at my dealer (Loeber in Chicago) told me to expect the battery to discharge about 1% per day when the car is sitting due to the many electronic devices in the car. I have been using a Battery Tender Plus for 2 years now with great results. I don't have any numbers to quote, but all I know is my '07 Carrera turns over noticeably slower if I have forgotten to attach the Battery Tender, especially in the winter. I still have the original battery. One other thing, I recently opened the trunk of a friend's 986 Boxster with a dead battery by feeding 12V DC through the cigarette lighter socket.

[mulekicker]

I left for vacation and returned to find my battery dead also. One day sitting in the car with the ignition key out, I heard a clicking. Came to find out the passenger seat adjustment control was stuck. Move the control back to off and no more battery issues.

[JFP in PA]

5 I use the CTEK but just be aware that if you have a power outage the CTEK will not restart itself and will need to be reset in order to work. If you are going to leave the car unattended for long periods of time the CTEK would not be my choice.

Strange, I have several Ctek's, mostly 3300 and 7002's, and they all reset automatically after a power outage...................

[JFP in PA]

random bits of info:

CTEK on a fully discharged battery will show that the battery is almost fully charged (not sure how it is possible but it is the case).

it is sufficient to open trunk.

Maintainers measure voltage to obtain state of charge. Interestingly, a nearly dead battery will measure full voltage, but not have enough current (amperage) to turn the motor over, usually due to extremely high internal resistance. That is why the standard shop test for battery condition is a load test, not a voltage test.

[jakkay968911]

Turning the ignition key in an effort to start my 2005 997, I got the dreaded clicking sound indicating not enough current to engage or turn the starter motor. I was fortunate enough to get the front lid open and expose the battery. I hooked up a trickle charger on the 10 amp setting and soon noticed an unusual noise. In the quiet of my garage I heard a dull, muffled clicking sound about every 45 seconds, then another 15 seconds later. This pattern was being repeated in a regular cycle as I tried to find the source of the sound. I noticed the needle on the amp meter of the charger would move as the sound occured indicating a slight draw of current. After a half hour I traced this muffled sound to the passenger seat power switch. All the positions of the switch worked except for the sliding motion. As I tried to move the seat back and forth with the switch I was able to duplicate the sound I was looking for. After trying to move the seat, somehow the noise went away and stopped drawing current as indicated by the amp meter needle. This may be a common problem that leads to starting issues. Does anyone else have any idea how to correct this problem? Is the power seat switch overly sensitive or could the motor or a relay be the source of the problem. Coincidently, I also noticed the rear spoiler was partially raised when I entered the garage, and I am positive it was down when I left the car the day before. Any help on these issues would be greatly appreciated.

[logray]

In a low voltage situation, all sorts of strange things can happen and you can throw predictability and reason out the door.

I would properly test and charge the battery, then monitor for these conditions again.

How old is the battery? Perhaps it is due for replacement.

[jakkay968911]

Thanks for the thoughts logray, but the battery is three months old and has been load tested two times in the last three months since this is not the first starting issue. Alternator was also tested. The low voltage situation can occur in as little as two days if something is unexpectedly drawing current. The noise I mentioned sounds like an electrical component of some kind trying to activate. The amp meter shows this as the needle indicates a cyclical pattern of current being drawn.

[logray]

Maybe you could try disconnecting the fuse or wire harness for the power seats, and see if the current leeching stops.

Also were the main power leads checked for corrosion? Ground and power.

[jakkay968911]

Thank you for the thoughts Logray. The battery is three months old and has been load tested on two previous occasions related to starting issues. The alternator has passed tests as well. It appears the low voltage situation happens as some electical component attempts to activate when the car sits in the garage for a day or two.

[jakkay968911]

The battery terminals are clean and tight as new. I will look for a fuse panel diagram and try your idea regarding the fuse removal for troubleshooting the problem. Thanks for the great idea.

[phillipj]

Hmmm.......Might want to check your engine compartment light as well as your boot light. Make sure they are going off as they should. You may just want to remove the bulbs as one of your troubleshooting processes..

Edited February 15, 2012 by Loren