Battery Died - Found no prev. thread here that helps.

I have a 2001 996 Turbo and the battery completely died in it. Using the method outlined here I pulled out the positive terminal in the fuse box and hooked up a DieHard 12V charger. Unfortunately, it is drawing no current at all. The charger is not broken, as it is brand new and I am able to read a voltage on it and everything. So, in essence, I am unable to get past Step 4 in the instructions. I moved to plan B. I attempted to access the manual trunk release behind the front bumper by jacking the car up, putting it on stands, buying a torque wrench (I am in the process of moving so half of my tools are in storage. I also bought the battery charger for this), and detaching the front passenger wheel. Unfortunately, the security key (which I forgot these wheels required) is located in the very compartment I am attempting to access, with the spare tire and tire pump. What do I do for plan C? Where do I go from here? I am at a complete loss as to what I can do to fix this car and get the battery recharged. It sits on jack stands awaiting further instructions.

http://www.renntech.org/forums/tutor...ttery-is-flat/ might prove helpful

Try step 4 again with a battery from another car or a portable lead acid (not lithium ion) jump starter. The charger may be too smart and it shuts down when it detects a dead battery or it just doesn't have enough amps.

Also, always store the security wheel lock key in the passenger compartment. I store mine in the ashtray with it wrapped in some napkin to avoid rattling.

Quotes source post: 13746581

Id second this, you need a battery or jumper pack a charger won't won't. They are relatively cheap and very handy

Thanks for the reply, people! The thing that ended up helping me (so far) was to fish out the hidden wire under the left tail light assembly and charge via the terminals in the engine. In this case, the charger reads a current and seems to be putting charge into the battery. One thing to note to anyone else who is fishing out the engine cover release wire: I found it best to pry on the inner part of the tail light (closer to the center of the car) and then peek towards the outer part of the tail light gap to find the release wire. In this case, it was already taped down via another thread on this board outlining how to position the wire in case something like this happens. Is there something inherently different between the + terminal in the fuse box vs. the + terminal in the engine bay?

From my understanding, the fuse box is only to give power to the car in the event of a dead battery to give access to the frunk and rear electronic release. From memory the manual says not to jump from the front only the rear also

That makes sense, though even in low power "battery charge" mode, or even with the trickle charger, I was not able to get any sort of current or effective charge via the fuse box terminal. I certainly wouldn't want to try to run the kind of current necessary to jump start the car through that fuse box. So I ran the higher current needed for a jump start (at the battery connection points on the engine) and the dash lights indeed came on, but then the rear spoiler lifted and the side windows went down. Is this a normal procedure, or should I just expect random things to happen during a jump?

So bow you have access to the engine compartment? How old ia the battery and how long has it been in this fully diacharged state? If it's long (a day or two), you may not be able to revive it.

I had this very situation a couple of weeks ago, despite having a less than 2 year old battery fortunately I had left the engine cover 'popped' and after 6 days with not having the alarm actuated, there was nothing after hooking up jumpers to the posts in engine compartment, about 20 minutes of transfer was necessary for a start fwiw, I always garage my car and have a a small battery tender installed in the frunk If I know I'm not going to drive it for a number of days, I pop the frunk as I exit the vehicle and plug in the battery tender hopefully your new residence will afford you garage storage and I'd recommend the installation of the battery tender in just over 2 years of ownership, that's the first incident of dead battery I've had and have no-one to blame but myself, I simply forgot to plug it in

A battery tender on the post doesn't give you enough power. Use a portable jump starter (make sure it's charged first!) and verify that the negative is appropriately grounded - took me some trial and error to figure out that the door anchor loop on the body near the seat is an effective point for the negative connection. Otherwise you can't complete the circuit. All in all, the electric frunk release is over engineered ridiculousness. Give me a standard cable pull any day.

The emergency cable release mods mentioned here are seldom done. So easy to do, so infuriating if you don't.Just like drain hole clearing,radiator cleaning. Another check is to search for a parasitic drain on the battery.If the battery is good but drains in a week, there is current leakage somewhere.Best to track it down before it strands you ? BTW the Cteck MUS 4.3 battery charger/maintainer is usually recommended by JFP and it can be connected via the interior power socket

Hey everyone! Thanks for all the helpful recommendations here. I was indeed able to get into the engine compartment and I hooked up jumper cables to my 3 series. After about 15 minutes I was finally able to get power to open up all the compartments and such. The engine still wouldn't start (gatling gun-type sound) so I waited for an hour. Then I could get a partial crank but still no start, so I waited another hour. Finally was able to get the engine started! Then I left the engine running for about 20 minutes, then proceeded to drive the car for another 20 minutes, keeping the 14V supplied by the alternator and keeping the engine RPM's in the mid range instead of down low. I then proceeded to daily it to several different locations today and the engine has been starting without issue. The battery was allowed to discharge for a good 2 weeks before the car started up again. Now I try to remember to keep a tender attached to the battery running out the front storage compartment whenever the car is parked. The battery was last replaced 2 years ago, though I've heard stories of the 996 eating through batteries every 3 years for some people. Should I seek out a battery with a higher cold crank amperage? It's currently rated at 700A. I'm used to my BMW's which can sit for weeks and start up without issue, though I hear that they require a much lower current to start the engine, so maybe that's why their batteries can last longer sitting around (?).

I switched to an AGM battery but still keep it on a tender.

i have had similar issues, if you dont use it for a couple of weeks, then (especially in cold) it wont even crank, and you need a big jump starting system to get it going. 2-3 years is about all i get out of the battery in london, uk. mostly due to short drives, and not using it for weeks at a time. i do notice over the summer months, with more use, the battery seems to get better. I await the you shouldnt do that, but have been known to park on a hill, so i can bump start it, before pulling the pin on a new battery(word of warning, you have no powersteering or power brakes until the engine fires). The bosch batterys i have found are not as good as the aftermarket ones. my only proof is it lasted 2 years, and the current one is on 3 and still ok. I have considered a battery tender, but the car spends most of its life out side on the steet, and i havent found a good solar trickle charge that has many reviews for 996( it not very sunny in london in winter).

** Also, make sure you always lock the car when not driving it. My battery was stoned dead when I bought my car. It needed a deep 24 hour charge to get it going again (this was done at an Interstate facility as the battery was under warrantee). Two years on and it has never even acted up since. When the car is garaged over the winter for maintenance work, I keep it on a battery tender... During the summer driving months I've left it for over a week without driving several times, but after opening with the key it fires right up every time

Quotes source post: 13750940

It is not a BMW vs Porsche issue. Neither make batteries. You need to test your battery for SOC/SOH (Search !) with a modern tester. Also test for Parasitic Drain as mentioned previously. Until you get those 2 test done and tell us the results, much else is a waste of time . Also check cables for corrosion under the insulation near the battery and the infamous "Y" connector. Note that the modern battery charger/tenders(like CTEK mentioned previously) are very much more sophisticated & effective than the old ones.They are much better at maintaining the long term 'health' of the battery on a car that is seldom used.