Why does my 997 drain its battery so quickly?
Discussion
I have an '06 Carrera 2S. I've had it four years. It had a replacement battery c2 years ago. I drive quite frequently (though usually only weekends), but mainly short distances. During the lockdown I've had to charge it twice as it had fully drained the battery after non use for 7-10 days. I've always been aware that the car drains its battery when not used, but why is this as none of my previous cars have done this (I've had quite a few over 35 years of driving)? I work with a guy who also had an 06 Carrera and unprompted he said to me when we were discussing the cars "make sure you drive it frequently as mine kept draining the battery". It doesn't especially bother me, I'm just curious as to why these cars do this. Any ideas?
Short version: lack of use (literally) and lack of time when in use. Battery is just a storage means, and if that storage is never topped up then eventually it will run out.
Best bet is to get a plug in battery conditioner on a quick release plug for convenience and keep it plugged in when not in use.
Best bet is to get a plug in battery conditioner on a quick release plug for convenience and keep it plugged in when not in use.
If your only doing short journeys (especially multiple starts) then the answer is your never charging the battery. Probably takes 20-30 mins depending on the alternator condition, battery state, how much electricity your using (lights, heated seats, window defrost etc). This ultimately degrades the battery faster resulting in a shorter serviceable life span for the battery.
If your using it so infrequently i would be looking at a battery conditioner to leave it plugged in (CTek make some good quality ones). On the Porsche i know that the 12v utility (fag lighter) is permanently wired to the battery so you can get an adapter to just plug it in there.
On my cayman i wired in some cables down to the front grill and used a couple of waterproof connectors so i could connect disconnect the charger whilst the car was still locked.
If your using it so infrequently i would be looking at a battery conditioner to leave it plugged in (CTek make some good quality ones). On the Porsche i know that the 12v utility (fag lighter) is permanently wired to the battery so you can get an adapter to just plug it in there.
On my cayman i wired in some cables down to the front grill and used a couple of waterproof connectors so i could connect disconnect the charger whilst the car was still locked.
If your battery ever gets drained to zero (ie: no lights on, no click from starter,etc.) then the battery is effectively ruined and will not be able to keep a charge any more after that. You just need to buy a new one. Something about the terminals inside sulphating or such like.
The reasons why it discharges can be infinite, from bad earths to equipment drains. Porsche UK fitted trackers to these cars and this would be one of my starting points. Short driving (ie: less than ~15min) doesn't help, especially if you restart a couple of times in the process or use many accessories. This is compounded in city driving with low engine speeds.
For reference, I have an 06 C4S and the battery is ok for up to 3 or 4 weeks. On week 4 its sometimes a bit "undecided" as to whether it will actually make it or not, usually goes for it though.
The reasons why it discharges can be infinite, from bad earths to equipment drains. Porsche UK fitted trackers to these cars and this would be one of my starting points. Short driving (ie: less than ~15min) doesn't help, especially if you restart a couple of times in the process or use many accessories. This is compounded in city driving with low engine speeds.
For reference, I have an 06 C4S and the battery is ok for up to 3 or 4 weeks. On week 4 its sometimes a bit "undecided" as to whether it will actually make it or not, usually goes for it though.
Thanks for the replies. I wonder whether the effort of starting takes more out of the 911 than other cars I've had. There's a voltage drop from the battery in the front and the starter in the back (had the cable renewed a while back) and then it turns over a big old lump. Perhaps, I simply need to drive it further after each start up in order to replenish the battery. Never had this with my £500 SAAB 93!!
I think the same - I have an e92 m3 and the battery constantly drains , but my journeys are no different to any other car I’ve owned, and They have never had any problem with batteries. All I can think is they install rubbish batteries - or the car uses a lot more battery power when running (again not sure why).
Gixer968CS said:
I have an '06 Carrera 2S. I've had it four years. It had a replacement battery c2 years ago. I drive quite frequently (though usually only weekends), but mainly short distances. During the lockdown I've had to charge it twice as it had fully drained the battery after non use for 7-10 days. I've always been aware that the car drains its battery when not used, but why is this as none of my previous cars have done this (I've had quite a few over 35 years of driving)? I work with a guy who also had an 06 Carrera and unprompted he said to me when we were discussing the cars "make sure you drive it frequently as mine kept draining the battery". It doesn't especially bother me, I'm just curious as to why these cars do this. Any ideas?
I had an 06 C2S that used to do that. Until the OPC found a forgotten tracker on it. Then it was fine.RiccardoG said:
If your battery ever gets drained to zero (ie: no lights on, no click from starter,etc.) then the battery is effectively ruined and will not be able to keep a charge any more after that. You just need to buy a new one. Something about the terminals inside sulphating or such like.
The reasons why it discharges can be infinite, from bad earths to equipment drains. Porsche UK fitted trackers to these cars and this would be one of my starting points. Short driving (ie: less than ~15min) doesn't help, especially if you restart a couple of times in the process or use many accessories. This is compounded in city driving with low engine speeds.
For reference, I have an 06 C4S and the battery is ok for up to 3 or 4 weeks. On week 4 its sometimes a bit "undecided" as to whether it will actually make it or not, usually goes for it though.
Not sure about that. I left my 986 frunk light on by accident (not closed properly) and the battery drained right down to 7V, so much so that the back-up alarm sounded which is when I knew something was wrong. It's a great big Bosch Silver Plus so i decided to try and save it.The reasons why it discharges can be infinite, from bad earths to equipment drains. Porsche UK fitted trackers to these cars and this would be one of my starting points. Short driving (ie: less than ~15min) doesn't help, especially if you restart a couple of times in the process or use many accessories. This is compounded in city driving with low engine speeds.
For reference, I have an 06 C4S and the battery is ok for up to 3 or 4 weeks. On week 4 its sometimes a bit "undecided" as to whether it will actually make it or not, usually goes for it though.
It took 2 days to charge it back up using my cheap charger and although it isn't perfect, I can leave the car over 7 days between starts no problem.
It may have been different if it had stayed massively discharged for a long period of time but if you charge it back up straight away, it may be OK.
Fnumber1user said:
Short version: lack of use (literally) and lack of time when in use. Battery is just a storage means, and if that storage is never topped up then eventually it will run out.
Best bet is to get a plug in battery conditioner on a quick release plug for convenience and keep it plugged in when not in use.
^ThisBest bet is to get a plug in battery conditioner on a quick release plug for convenience and keep it plugged in when not in use.
I too thought a CTEK was the answer for a low battery until one day, freshly off the conditioner, my 981 wouldn't start.
Turned over fine, very quickly which was strange. Turned out to be the battery having enough juice to turn the engine but not to start it. Flooded the engine (remember that?) in the process but I didn't realise that was what was occurring. Engine turned quickly due to loss of compression as any oil languishing in the cylinders had been washed away by the surplus petrol.
A new battery sorted it at my local indy after they sussed what had happened.
I won't leave it so long to get a new battery next time it doesn't want to start.
Turned over fine, very quickly which was strange. Turned out to be the battery having enough juice to turn the engine but not to start it. Flooded the engine (remember that?) in the process but I didn't realise that was what was occurring. Engine turned quickly due to loss of compression as any oil languishing in the cylinders had been washed away by the surplus petrol.
A new battery sorted it at my local indy after they sussed what had happened.
I won't leave it so long to get a new battery next time it doesn't want to start.
Gixer968CS said:
I have an '06 Carrera 2S. I've had it four years. It had a replacement battery c2 years ago. I drive quite frequently (though usually only weekends), but mainly short distances. During the lockdown I've had to charge it twice as it had fully drained the battery after non use for 7-10 days. I've always been aware that the car drains its battery when not used, but why is this as none of my previous cars have done this (I've had quite a few over 35 years of driving)? I work with a guy who also had an 06 Carrera and unprompted he said to me when we were discussing the cars "make sure you drive it frequently as mine kept draining the battery". It doesn't especially bother me, I'm just curious as to why these cars do this. Any ideas?
I’ve had 3 Boxsters & for the last 5 years a 2007 997.1 C2S every one of these cars has had the Same problem you are describing. It’s a Porsche thing. Get a trickle charger ( CTEK ) & your car/battery problems should be sorted.Mariosbt said:
Gixer968CS said:
I have an '06 Carrera 2S. I've had it four years. It had a replacement battery c2 years ago. I drive quite frequently (though usually only weekends), but mainly short distances. During the lockdown I've had to charge it twice as it had fully drained the battery after non use for 7-10 days. I've always been aware that the car drains its battery when not used, but why is this as none of my previous cars have done this (I've had quite a few over 35 years of driving)? I work with a guy who also had an 06 Carrera and unprompted he said to me when we were discussing the cars "make sure you drive it frequently as mine kept draining the battery". It doesn't especially bother me, I'm just curious as to why these cars do this. Any ideas?
I’ve had 3 Boxsters & for the last 5 years a 2007 997.1 C2S every one of these cars has had the Same problem you are describing. It’s a Porsche thing. Get a trickle charger ( CTEK ) & your car/battery problems should be sorted.My 911, with new top quality Bosch battery, needs continuous trickle charge or it will not start reliably after a couple of weeks. My F10 M5 starts without charge more than double that period.
My old 997 used to do this after any longer than 10 days. I had a new BMW too at the time which started fine after 3 months.
It might sound an over reaction but it was one of the factors which contributed to me getting rid of the Porsche. I like an easy life and there was too many negatives with the 997. Drive was good though!
It might sound an over reaction but it was one of the factors which contributed to me getting rid of the Porsche. I like an easy life and there was too many negatives with the 997. Drive was good though!
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