ChemMan

Took the 996TT out for a drive today. I have not driven the Porsche since Monday, so six days. Stopped by to see my parents. When I was leaving, turned the key and nothing, just the starter clicking. Voltage when I left home on the cluster read 14V. When I failed to start, it read 12V.

Put a jump box on the battery, it started and drove home.

After a 15 minute drive home and into the garage, voltage as follows:

Engine 0ff: 12.52V
At idle, no load: 13.65V
At idle, with low beams and ac on: 13.13V

No voltage drop across either terminals.

I am assuming, it is either the voltage regulator, alternator, or the battery itself.

If you could help me troubleshoot this problem, I would appreciate it.

Thanks in Advance!

ChemMan

Had my wife take the engine to 1500 rmp and then 2000 rmp. Voltage stayed at 13.70V.

Macster

The battery voltage readings when the engine was running and with various electrical loads is about par for the course based on what I see from my car's battery voltage gage.

Turbo battery life is not very good. The car must be driven frequently -- if one can't use a battery maintainer -- to keep the battery charged.

If one goes too long between uses the battery gets low on charge and while if the car is driven enough gets replenished the low charge condition takes its toll on the battery.

Also, 12.52V is not that good of a charge. Better than 75% but not up to 100%.

So off hand I'd say the battery is the problem.

dhc3

Same issue here yesterday. Car had sat 6 days as it often does. ChemMan did you replace your battery? Results?

ChemMan

All of this just happened yesterday. I will replace the battery tomorrow and report back. Thanks for the replies.

Carlo_Carrera

I think you should full charge your existing battery and then drive to an Autozone for a free and complete charging system check.

wross996tt

Battery and put the new one on a maintainer!!

Montescew

No doubt with regard to "being driven frequently" or else. The only other car that i owned in the past which required serious cranking power like ours is a '92 500e.

I would definitely start with the battery test. Good luck.

Macster

If it is the battery and I think it is it has been going on ever since you installed the new battery. These cars are hard on batteries. Not so much the starting effort just the battery drain when the engine is off is high.

Also, I would hazard a guess the alternator is while not weak let me just say undersized. Probably to reduce weight and parasitic losses. But a result is it takes longer to replenish the battery after an engine start and many owners just don't drive the car that much after an engine start. Definitely not the car to use for short hops and errands.

You start it you drive it. Miles.

I use my Turbo 2 or 3 times a week and at least 2 of those times I drive it to work and back, 60 miles.

Just thinking out loud next time I have to replace a battery in the Turbo I'm going to explore getting one with more AH's. The stock Turbo battery is the same "size" one that's in my Boxster and for the Boxster the battery is superb. For the Turbo, not so much.

djmacabre

Hmm. After 4 or more days not driving my (new to me) 996 turbo, the remote unlock on my key doesn't work. I have to manually unlock the car, then reset the little dash button that says the alarm went off. Maybe I need to look into testing my battery...

dhc3

Quick update on my situation; pulled the battery and full charge and test at O'Reilly showed bad battery. After the holiday will get a new one. Happy 4th!!

fpb111

Normal, car goes into sleep mode to save the battery after 5 days of inactivity.

Macster

Battery may be suspect or getting weak due to lack of use but remote lock behavior is normal (as fpb111 correctly states but I'll not use any emoticon) and has nothing to do with the car's battery condition.

In this case what you can do is use the key blade to unlock the door then within something like 10 seconds insert the key into the ignition and turn the key to the 1st position. This prevents the alarm from sounding.

Just to reinforce this: If you are finding the car's security system refusing to recognize your key's door unlock signal you are not driving your Turbo enough. Either drive it more frequently and for enough miles to fully replenish the battery or consider using a battery maintainer/conditioner to keep the battery healthier from lack of regular use.

"02996ttx50

short jaunts do nothing to maintain the integrity of the battery in this volt hog. that the ecu deigns to put the REMOTE to "sleep" is porsche's version of an impish prank. a trickle charger is a must.

ChemMan

I changed the battery a couple of days ago. Everything seems fine now. In the middle of another car project. Just got the point where we have to wait for parts so will be checking for the phantom draw this week.
Thanks for all the help.