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How to set up CTEK charger/conditioner to 12v cigarette plug

findtom

Nurburgring
Joined
18 Mar 2009
Messages
376
Background:
My 992 C4S arrived 3 days before lockdown. The car had only done about 200 miles in the middle of March, (from the dealership to home), so by the time we got the end of April I decided to buy a battery charger. I have had a few 911's and as with any modern internet connected car they do tend to drain their batteries if left unussed for weeks at a time. I have previously used the Porsche Charge-O-Mat on my 991.1 and 991.2 but after reading the "good to know" manual, I worked out that I had a Lithium battery and that my charger would not charge it. I was then left with two choices: buy another Porsche charger, (my preferred action, I'll explain why shortly) or buy a CTEK charger. Sadly, finding a Porsche charger provide quite difficult. Many dealers where closed and even the few that were manned, either didn't have stock or couldn't get it to me for a month or so. I decided to look at a CTEK charger as they are essentially the same as the Porsche version. Only there are some tiny differences, namely the charging profile. How the charger initiations the charge and I believe a subtle change to the pulse, (but I am way outside of my knowledge here so feel free to correct me). From memory, on the 991 if you wanted to use the 12v charging socket vice connecting direct to the battery, it was easier if you had the smoking package as that gave you a permanently powered 12v socket in the centre console. Even if you opt for the smoking package on a 992 you do not get an additional 12v socket. There is a standard one in the passenger footwell but it is not permanently powered unless you use a Porsche charger or follow the procedure below. The issue is that once the ignition is turned off the car protects itself and disconnects the internal 12v socket after 30 mins.

I ordered my CTEK not realising that it wasn't totally plug and leave like the Porsche system. The first time I used it, it just worked, (I got lucky). Imagine my confusion when after I had moved the car to wash it and then put it back on charge, it kept stopping after 30 mins...... It took me a few days to figure out what was going on, connecting the charger and coming back next day to a green blinking light, (meaning it was disconnected from the car). After a lot of research and speaking to my dealer we figured out that the 30 mins shut down could be overridden quite simply, (see below). I can confirm this works for my car (Feb 20 build) using the kit listed below. Hopefully this will help someone else as I could not find an answer anywhere on how to override the 30 min cut off without resorting to buying a Porsche charger or leaving a wire permanently connected to the battery.

Conclusion:
You can charge the car using a non-Porsche cigarette adapter (CTEK) by using the procedure below.
The Porsche-O-Mat just works and is a true plug and play. (Based only on my 991 experience. Can someone confirm that is true of the 992)?
You can also connect a non-Porsche charger direct to the battery, but most people leave a wire in the boot. (Connect to the battery terminal and the other lead to the terminal post in the car, DO NOT CONNECT BOTH CHARGER LEADS DIRECT TO THE BATTERY - See Porsche "good to know" about batteries for more info). I didn't not want to do this as I found the 12v cigarette adaptor method much simpler.

Setup:
CTEK Lithium XS charger and conditioner 12v 5A
CTEK Cigarette Lighter Lead - 12v
CTEK 2.5 Meter Comfort Extension Lead
My car: Feb 20 Build 992 C4S with rear-steer - LiFePO4 Battery

Procedure to keep 12v internal socket active:
Connect your charger to the 12v socket - Car ignition off, Charger NOT plugged into the wall.
Charger connected to the 12v socket - Car ignition on, plug in (turn on) charger.
Check lights on charger are moving through steps 1/2/3 etc
Turn ignition off - Charger lights should still be lit. You are good to go and the 12v socket should now stay live.

If your charger is flashing green (No other lights just the light bottom left in the photo below), then the car has disconnected the circuit and you need to try again.

The photo below is how your charger should look after a few hours if it's happy.
 

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Personally I prefer to use the 'pig-tail' connector that goes to the battery and body earth rather than have it on the fag lighter.

Lots do but I'm not comfortable with forcing a current via the fag pipe to the battery when I can connect it direct to the +ve terminal.
 
I can understand your logic, but it is how Porsche designed it to work. If you buy the Porsche charger it comes with the cigarette lighter attachment only. You have to buy a separate bit to connect direct to the battery.

:thumbs:
 
My C-Tek just plugs into the cigarette lighter and stays on until I need to use the car.

I route the cable at the front on the door, just in front of the wing mirror.
 
Thanks. Are you still driving a 997 as per your signature? The 992 will disconnect power the the internal 12v socket after 30 mins if you don't follow the process above.
 
Yes, sorry!

The joys of electronic advancement...
 
I have just overcome the exact same issue a Porsche version of the CTEK had it plugged into the cig socket and the battery went flat called out the nice man with the yellow van , he confirmed the cig socket is not live when the keys are out mmmm clever porsche lol . he Kindly added a couple of connectors on leads from the battery and cut the cig bit off my Ctek joined connectors to the ends and I now have a nice little F/M set up that I can shut the trunk on with no damage and no risk of metal touching the wires which was his worry if he had used crocodile clips to rig it up. and keep the battery conditioned. , I asked him to do the rig up that goes under the scuttle cover but he was not quite that generous lol. :grin:
 
This is exactly why I made this post. I think, if you have a 12v socket in the passenger footwell then its on a timer, unless you follow the process above.

I had the smokers package in my 991.2, that 12v socket stayed live.
 
findtom said:
A 992? Each to there own mate, not sure I would risk cheap charger on my 911.

And me ! check the cost of a replacement Lithium battery for this car ....nah...CTEX for sure, as this is a long duration used appliance used without supervision.
 
Hi
I've had a few forays into charging my 992S. The battery is AGM (i.e. Lead not Li-Ion, despite what the brace sticker says) and I negotiated a complimentary Porsche charger when I bought the car.

However first time out I had the same issue trying to use the passenger footwell socket with timing-out when you close/lock the car. I subsequently requested the crocodile clip adaptor be sent which connects direct to both battery terminals.

I had a problem this weekend with a flat battery (see my other post) but the charger worked a treat overnight. The nice man from the AA fed the croc clips wires under the cowl into the frunk so I can connect up the charger easily for future use.
 

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Looks like a handy point for the negative from the charger, right by the battery.
 
Just for comparison, this is a photo of a LiFePO4 battery. Note my brace sticker is different to the AGM version in the photo above.
 

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