987.2 battery drain problem ?

[Medic-one]

So I was supposed to go view a 2011 987.2  3.4 S PDK this Saturday, but the owner has now said that the battery was drained again so he's booked it in with his local Porsche dealer to have to examined. 

I've got through his posts on a Boxster facebook group, and in March 2020 he posted the following : 

"Something is draining the battery after my car went in for servicing, so much so that it won't trickle charge. Can't be sorted now because of lock down.
Can anyone tell me either how to remove the battery without setting the alarm off or how to lock the passenger door once the battery is removed?"

Reading through his posts he stated there was nothing left in the arm rest power socket, but no real fix was given I think.

When I asked him about it he send me a picture of the heater controle unit (with the buttons of the heater and temp settings) and said he to replace that, and he had the PCM repaired (as that was rebooting occasionally) and he had a new battery fitted.  

But obviously something is still draining the battery, is this a common problem and/or has anyone else had a battery draining problem ? 

He seems like a genuinely nice guy who is trying to sort this problem before selling the car, so I'm happy to wait until it goes in next month, but just curious to what it could be.  

[iborguk]

No this isn't a common problem.

If the the car isn’t being used much then the recommendation would be stick it on a trickle charger to keep the battery in good condition. Porsche original batteries in particular don’t tend to last well without doing this. But from what you’ve said the battery has been replaced anyway. Would be interesting to know with what.

Anything else here is guess work and try we’re talking about a car you haven’t seen yet , let alone had a chance to get inspected , so it’s all a bit speculative. 

Let’s say you had the car in front  of you, what should be asked/looked at? Some starters for ten...

What was the fault with the heater control unit and why was that associated with the original battery drain issue ?

How long does it take for the drain issue to manifest ?

Has the new battery been verified as good ? 

Is the alternator good ?

The draining circuit needs to be identified with a diagnostic or if doing it DIY I guess pulling fuses and waiting to see if it reoccurs might help zero In on the offending circuit/item.

Any third party bits e.g tracker installed on the car ? 

How often is the car driven ? 

Is it normally on a trickle charger if not used for long periods (say several weeks) ? 

Edited April 23, 2021 by iborguk

[Paul P]

internet remote diagnosis at it's best, but a few things come to mind - as above trackers/road angels anything strange hooked to the wiring - a lot of cars are prepped for ( or shipped with VTS - the vehicle tracking system - have read of that going bad and causing a drain )

Alternator - had this on other cars - black box ( regulator/rectifier in old money) goes bad - leaches battery to earth.

Things like interior lights should switch off after about 20 mins - but worth a phone videoing the boot(s) shutting and verifying the lights went off.

 

 

[Pinewood]

my 997.2 is on the original battery and quite likely the car you're due to view is also. That's a 12 year old battery. I'm plugging mine into a CTEK if not used for 5+ days, not because I have an issue but to prevent an issue occurring. 

Will replace mine this summer, as it's a matter of when, not if it will fail in the not to distance future. 

The 987.2 isn't known for battery drain issues 

Edited April 22, 2021 by Pinewood

[Medic-one]

Charge folks, that's very helpful. 

So he said I'm still welcome to come view and drive ve the car tomorrow so I'll definitely go do that, so I know it's the car I want, and then I can ask some of the questions listed above. 

He said its booked in with an OPC who said its £ 192, to plug it into some diagnostics computer. Would that pick up things like alternator problems etc as well or just electrical problems? 

[Menoporsche]

I’ll be so bold:

if you really like this car as it’s the perfect spec/price and few good ones are on the market now, assuming it’s priced at 15k plus, ask for 500 quid off, buy it and fix it yourself. 
 

It is unlikely to cost 1k to fix a battery drain issue, and even if it does you’ve only paid 500 extra to get the car you want. Which in the price range 15-20k is negligible. 
 

I might be wrong but it’s a point of view. 

[Gutley]

Seems to me that if he pops it down to his OPC every time he has a problem it’s probably a well looked after car. 

[Medic-one]

30 minutes ago, Menoporsche said:

I’ll be so bold:

if you really like this car as it’s the perfect spec/price and few good ones are on the market now, assuming it’s priced at 15k plus, ask for 500 quid off, buy it and fix it yourself. 
 

It is unlikely to cost 1k to fix a battery drain issue, and even if it does you’ve only paid 500 extra to get the car you want. Which in the price range 15-20k is negligible. 
 

I might be wrong but it’s a point of view. 

I did consider that, but I just want to drive and enjoy it, not having to take it to garages trying to fix problems just after buying it. 

It's up for £ 21.750, but I guess there always room for a bit of haggling. 

[Medic-one]

27 minutes ago, Gutley said:

Seems to me that if he pops it down to his OPC every time he has a problem it’s probably a well looked after car. 

This, plus he was honest and upfront about it. He could have just charged it up and not tell me, but he didn't. 

[iborguk]

5 minutes ago, Medic-one said:

This, plus he was honest and upfront about it. He could have just charged it up and not tell me, but he didn't. 

Yes it’s a good sign he wants to sort it and I wouldn’t want to take on a car with a known problem from the get going at that sort of money.

You’ll hear  folks talk about PIWIS and that’s the Porsche Diagnostic system (whether that’s able to detect a vampire circuit draining the battery I don’t know but it can report OBD type error codes (which may not help here) and live values from the car (voltage etc).

[Steve Laming]

A couple of days ago a pal of mine sent me a picture of a 2011 Cayman. He said it was in for a battery drain problem.

0.55amps being drawn.

Disconnecting the radio seemed to do the trick.

Parts apparently (from Porsche) £2000 to fix. Is this PCM ?

[iborguk]

28 minutes ago, Steve Laming said:

A couple of days ago a pal of mine sent me a picture of a 2011 Cayman. He said it was in for a battery drain problem.

0.55amps being drawn.

Disconnecting the radio seemed to do the trick.

Parts apparently (from Porsche) £2000 to fix. Is this PCM ?

Yes the Porsche Communication Management (PCM) is the infotainment and Nav system including the radio.

[½cwt]

Not specific to this but there was an interesting section on how batteries deteriorate if just standing in last night's Car SOS.  Lead sulfation apparently as Tim dissected an old Bosch battery. Battery conditioner was given as the answer which happened to be a CTEK unit.

[DaveEFI]

3 hours ago, Medic-one said:

Charge folks, that's very helpful. 

So he said I'm still welcome to come view and drive ve the car tomorrow so I'll definitely go do that, so I know it's the car I want, and then I can ask some of the questions listed above. 

He said its booked in with an OPC who said its £ 192, to plug it into some diagnostics computer. Would that pick up things like alternator problems etc as well or just electrical problems? 

You don't need fancy equipment to check the alternator is OK. A simple voltmeter is all that is needed. Before worrying, ask him how long the car was left unused. Most modern cars with a good battery can manage 3 weeks at least. And if started, a reasonable length run to charge the battery. If the car is for sale, this might not have happened.

[Davey P]

My advice, for what it's worth, is walk away.  There are loads of Boxsters for sale all the time, it's not a rare car.  I wouldn't want to buy any car with a known fault from March 2020 that still hasn't been sorted after more than a year.  Your budget of £21K+ should get you an absolutely perfect example.  Just my opinion, obviously.

[iborguk]

7 minutes ago, Davey P said:

My advice, for what it's worth, is walk away.  There are loads of Boxsters for sale all the time, it's not a rare car.  I wouldn't want to buy any car with a known fault from March 2020 that still hasn't been sorted after more than a year.  Your budget of £21K+ should get you an absolutely perfect example.  Just my opinion, obviously.

I missed the March 2020 bit , yeah you'd have thought that would be sorted by now.

[DaveEFI]

2 hours ago, Davey P said:

My advice, for what it's worth, is walk away.  There are loads of Boxsters for sale all the time, it's not a rare car.  I wouldn't want to buy any car with a known fault from March 2020 that still hasn't been sorted after more than a year.  Your budget of £21K+ should get you an absolutely perfect example.  Just my opinion, obviously.

I doubt you'll find any 10 year old car perfect in every way?

[DaveEFI]

4 hours ago, ½cwt said:

Not specific to this but there was an interesting section on how batteries deteriorate if just standing in last night's Car SOS.  Lead sulfation apparently as Tim dissected an old Bosch battery. Battery conditioner was given as the answer which happened to be a CTEK unit.

I'd take that with the same pinch of salt as most else on Car SOS.  A lead acid battery doesn't deteriorate that much by just standing. But does when run flat while left connected - as pretty well, every car built in the last 50 years takes some current when parked up. And a knackered battery is just that. Even the much hyped CTEK can't do anything about that.

[½cwt]

32 minutes ago, DaveEFI said:

I'd take that with the same pinch of salt as most else on Car SOS.  A lead acid battery doesn't deteriorate that much by just standing. But does when run flat while left connected - as pretty well, every car built in the last 50 years takes some current when parked up. And a knackered battery is just that. Even the much hyped CTEK can't do anything about that.

What you said is exactly what he suggested. A connected battery will drain and deteriorate unless kept in condition or the car used regularly to keep it charged.  The reason, or explanation of the chemical process that causes the deterioration, was what I didn't know before, therefore a conditioner will do a lot to slow the eventual deterioration if used from new on a replacement battery.

[Menoporsche]

47 minutes ago, DaveEFI said:

And a knackered battery is just that. Even the much hyped CTEK can't do anything about that.

But the Aldi one is much better.

[Jonttt]

My 987 is in storage for 6 months of the year on a CTEK charger / maintainer.....

the other 6 months of the year the car is sat on my drive, it can be hardly used over a couple of weeks (especially last year with covid restrictions)......I have to occassionally put it on a battery charger......so I ended up fitting a bluetooth battery monitor (c£20) which was brilliant for telling me that there was no problem with the battery or the alernator but it was just a constant small drain on the battery which is normal.......this year I have bought a solar battery charger which I leave plugged into the passenger footwell socket and simply place on the dashboard when not in use, battery has been 100% charged all the time ie the solar charger is more than enough to compensate for the normal drain......

Batteries do degregate over time and also can be discharged too low where they are damaged and will not retain a charge properly....

I would be checking the mileage the car has been doing over the past year (MOT records etc....) and if its low simply put it down to normal battery drain...worst case new battery 

[DaveEFI]

1 hour ago, ½cwt said:

What you said is exactly what he suggested. A connected battery will drain and deteriorate unless kept in condition or the car used regularly to keep it charged.  The reason, or explanation of the chemical process that causes the deterioration, was what I didn't know before, therefore a conditioner will do a lot to slow the eventual deterioration if used from new on a replacement battery.

All you need to do to get the best life out of a battery is not let it get flat - or even too low. A car used every day or so will ensure it stays good. If you have a car not used much, of course a trickle charger is a good idea. But no charger will bring a damaged battery back to as new.

[iborguk]

2 hours ago, Menoporsche said:

But the Aldi one is much better.

Every Lidl helps

[Paul P]

All guesswork since we don’t know the full background but to me it sounds more like an actually issue with parasitic drain than simply “battery goes flat sooner or later in a boxster that doesn’t get driven much “

Sounds like the owner has been chasing the problem for a while and for whatever reason hasn’t been able to get resolution.  
 

no money has changed hands and it’s booked in for a fix. If the seller is honest enough to tell you about the fault then they will likely be transparent about the findings and if it’s fixed I don’t see any issue with at least considering the car.  
 

I would be tempted to at least argue fir a replacement battery irrespective of the age of the current one since if there has been charging or draining by issues and or the car has stood for a while then nothing “good” has happened to the battery and it’s leverage for negotiation. 
 

just my (Ctek conditioned - other cheaper and just as good if not better brands are available if you want ) 12 to 14 and a bit ish volts worth of opinion.  

 

[Medic-one]

I'm gonna drive over to London this afternoon with a whole list of questions to ask, and to drive a pdk for the first time. 

Thanks again for all the help so far folks.