Battery flatter than flat!

Technical Forum for the Porsche Macan
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oldpilot
Posts: 90
Joined: Sat May 27, 2017 11:38 am

Post by oldpilot »

My 2018MY Macan S has been locked up in my garage in Provence since last June and for obvious reasons I have not yet been able to recover it.

Back in February, I received a text from Vodafone saying that the CarConnect app had lost contact with the car (clearly a battery issue after all that time).

My 80 year-old neighbour in France was suffering from a raft of medical issues and I didn't want him to have a heart attack climbing my steep driveway to put the charger on - so I just left it.

However, said neighbour called yesterday, saying could he help me out by charging the battery. The car has keyless entry and of course wouldn't open up for him, so I talked him through dismantling the key fob and using the emergency key.

Having gained entry, he put one of those "smart" battery chargers on to the connections under the bonnet and could only get an error message. Not to be defeated, he found a really old-fashioned charger and connected that. After 24 hours, still nothing. Still not to be defeated, he tried one of those cheap and cheerful rapid start devices (from Lidl) and then engine would not even turn over and no lights appeared anywhere with the ignition on.

A quick call to my OPC (Tonbridge) revealed that if he could get the car to start, the AGM battery may well come back to life after leaving running for an hour or so. He explained that the Macan does not have an alternator, but a generator, which can completely recharge the battery. Not sure if I completely understand that line of thinking!

Does anybody have any ideas why the engine wouldn't even turn over using the quick starter (he tried two of them). He uses this gadget to start a very old MGB that gets about 2 outings a year, so he expected it to work.

OPC also cautioned me about putting anything other than a Porsche replacement battery on the car as the extended warranty would be invalidated.

He did say that if I obtained a genuine battery from a local OPC in France, everything should work just fine and that they would register the battery to the vehicle for me when I get the car back to England. Apparently registration is necessary to tell the electronics when a new battery has been installed.

On-Track
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Joined: Sun May 03, 2015 12:59 pm
Location: Staffordshire

Post by On-Track »

Does not sound good. I'd suggest contacting Porsche Assistance and ask them to liaise with their French equivalent to call round and get the car started.

A few points from your post. Your neighbour has used a "really old fashioned" charger when the "smart" charger didn't work. The problem with old style chargers is "ripple" on the dc current. This can have a nasty effect on the car's electronics.

Whoever you spoke to at Tonbridge either has no idea what he's talking about or is getting his terminology mixed up (or both). When I learnt to drive in the 1960s, cars had dynamos, sometimes called generators. Now they have alternators sometimes called AC generators. Alternators (AC generators) produce alternating current (ac) which is then rectified to direct current (dc). Modern alternators have a larger number of poles than older ones which produces a smoother dc when rectified.

Good luck.
Peter

Current: 2020 Carmine Red GTS http://www.porsche-code.com/PMST9ZI9
Gone- 2015 Sapphire Blue Diesel
Gone -2013 Cayenne Diesel
JurassicGTS
Posts: 471
Joined: Thu Jun 18, 2020 7:19 pm
Location: Sunny Dorset and Marbella

Post by JurassicGTS »

Worrying times for us fortunate enough to have cars left at our other homes.
My SL500 has been lying up in Marbella since April last year.
I did disconnect the battery before I left, but fear new tyres at least will be required, but just not even running for a year..fuel degradation etc., I wonder what else might happen.
Plus no idea when we will be able go visit foreign climes again😥
2018 Macan GTS Carmine Red
2023 Boxster GTS 4.0 Arctic Grey
2023 Cupra Born V2 77kWh Glacier White
oldpilot
Posts: 90
Joined: Sat May 27, 2017 11:38 am

Post by oldpilot »

Peter

Many thanks for your reply. Exactly what I understood before getting on the phone to OPC Tonbridge. Rather worryingly, the bloke I spoke to was the Technical Manager!

I learned to drive in 1961, so I'm with you.

Not a lot to be done until I get down there in June.
Madelvic
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Joined: Thu Aug 15, 2019 3:48 pm
Location: Scotland

Post by Madelvic »

I have 3 chargers. I would have hoped a smart (eg CTEK) charger might recover the battery.

Quick start devices might only be good for cars with small engines. I tried one on a diesel Kia and it didn’t have enough oomph to turn the engine over. Also the contacts need to be on really secure as there is big current needed to start any car

Possibly a heavy duty charger left on for 24 hours might get enough to allow the smart charger to work

And alternator not generator. Not got 48v systems yet
2017 Macan GTS Carmine Red
2005 Boxster S Artic Silver
TheTraveller
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Joined: Fri Nov 02, 2018 9:30 pm
Location: South Yorkshire

Post by TheTraveller »

TBH I would be careful when connecting an heavy duty charger, to the vehicle, or in fact any vehicle with an alternator. They dont like strong power being pushed through them. The best way would be to disconect the alternator. But I can envisage that would be difficult for most people, who have to get down into the engine bay to do so. The only other way would be to disconnect the battery. But then when connected back up, the system would want re-setting up, by imputting the details.
Just yesterday, due to the ongoing thread about changing batteries, I asked a friend and his mech's, if the vehicles which needed re coding would start without doing so. They couldn't answer it, they have never tried.
MikeM
Posts: 2234
Joined: Tue Nov 17, 2015 11:13 pm

Post by MikeM »

It’s clearly deeply discharged. It can ( dependent on normal state of age before discharge) be brought back to life. However you say that a Smart charger has already been tried, but what model type? If it’s hooked up to such as a CTEK MXS-5, or (bit overkill normally) a 7 and you select the correct mode it should pick up although it will take a few days, if it does the job then just leave it on in maintenance mode.
If it doesn’t do it, then a new battery is required, but cheaper to try first and you should just then leave it on permanently if the vehicle is infrequently used. Have had up to four going throughout lockdown with two vehicles connected all year round, no issues. By the way, re your OPC comment, there’s no such thing as a genuine Porsche battery! it will probably be a Varta and if you do disconnect/ change it without inputting the new serial/spec etc Porsche state that this can affect the condition control outputs? But of course it will start!

https://www.ctek.com/uk/products/car

E994E75B-0E3E-4C0D-92EB-FD7F5DADF6F3.jpeg

Previous Porsche’s
2008. 987 Boxster S Sport basalt
2012. 991 Carrera S aqua
2016. Macan Turbo volcano
Current
2020. Macan GTS crayon
2024. Macan GTS gentian sometime this year https://configurator.porsche.com/porsche-code/PR8H7WC6
oldpilot
Posts: 90
Joined: Sat May 27, 2017 11:38 am

Post by oldpilot »

Thanks everybody for your input.

I have a C-Tek charger, but it's here in the UK. I will certainly take it down to France and try that before anything else.

Point taken about feeble jump starters. If it won't turn the engine over, it can't be beefy enough. If C-Tek option above doesn't work, I'll mosey down to the local Renault garage and borrow their serious one to try that. I notice that one of you mentioned that alternators "don't like" to be hit with a jump starter, but surely these things are used all the time in case of need?

Regarding the Porsche battery; I'll speak to Tonbridge OPC for clarification, but they have already stated that if I buy a new battery from Porsche in Puget-sur-Argens (my local French OPC), I can fit the battery myself and they will register it to the car when I get it back to Blighty for its first MOT!!!

If you're telling me that it won't have Porsche written on it, surely I can try to buy the identical type - or won't that work warranty-wise - are there special serial numbers unique to Porsche?
On-Track
Posts: 2135
Joined: Sun May 03, 2015 12:59 pm
Location: Staffordshire

Post by On-Track »

As Mike has said, the battery fitted to your car is probably a Varta but Bosch also make similar batteries. It will be either a 95AH or 105AH AGM battery and does not carry any Porsche identifying marks.

There are C-Tec accessories available on Amazon that will allow you to semi-permanently connect the charger to the car. Read through the topic below for further information.

viewtopic.php?f=24&t=10563
Peter

Current: 2020 Carmine Red GTS http://www.porsche-code.com/PMST9ZI9
Gone- 2015 Sapphire Blue Diesel
Gone -2013 Cayenne Diesel
TheTraveller
Posts: 621
Joined: Fri Nov 02, 2018 9:30 pm
Location: South Yorkshire

Post by TheTraveller »

HD Jump starters are ok to start the car, just for that moment. But not to charge the battery, without disconnecting the alternator. But if the battery is so totally flat, as soon as the leads are removed, it will stop as there is nothing in the battery to keep it going.
I have a different model conditioner, and it states that it is only a conditioner, with very minute power going to the battery. And goes on to say it will not charge a battery from flat. If they all work the same, then the CTech, maybe the same.
Through the years many Porsche owners have said that when a battery on a Porsche goes flat, that's it. It's a gonner. Unless things have changed, a new battery may be the order of the day.
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