Charging via the cigarette lighter (assuming you have the lighter).

I try to be careful handling the unit and not pick it up or carry it by the cords. Over time, they can break. Lesson Learned. In the following pictures, this 4.3 is almost 5 years old. It works fine. Follow at your own risk. The downside to this is if there is a power outage, then the charger should not restart. Caveat Emptor. The upside is that its simple, trivial to get the hang of, and unlike the hood, the doors are probably designed to be opened and closed many, many more times than a hood.

Step 1

Turn the key to accessory position. The car wakes up.

Step 2

Remove the cigarette lighter. Put it in that tiny ashtray so you don’t lose it. Makes sure the plug is pushed all the way in for good contact. Sometimes people complain about a loose connection. I suspect they just didn’t get a good initial connection.

Step 3

Run the wire across the driver seat toward the door. Here, the cigarette plug is connected to the 8’ extension.

Step 4

Run the cord out the bottom of the door. I know this might freak somebody out who might wants to run it out of the window but the door has a rubber piece on the bottom that you can’t see. It doesn’t seem to harm the car or the wire and the door shuts. But, do whatever makes you happy. If your worried about it crimping or harming the body, then figure out some other way to get the cord out. This is also a good reason to use the 8’ extension. If you damage the extension, it cost maybe $11 for a new one. If you damage the actual cord, you probably need a new charger.

Step 5

Plug in the CTEK. Make sure the correct lights are on. It should move to the third light very quickly. If you get an error, figure out why.

Step 6

Turn the key off. If it’s a real key, remove it. Close and lock the door

Step 7

This is my experience. The first 3 lights should turn on quickly. According to the manual, the unit does not go to the fourth light until the battery is 80% charged. It could take, per the manual, up to 20 hours. If the lights sits at the 3rd light for a long time, I think its telling me the battery is run down. I like to see it go from the third light to fourth within no more than 10 mins, which tells me, with no proof, that’s the battery is really no more than 80% discharged. At the fourth light, it’s just patience. It’s supposed to take no more than 10 hours. Once it moves to the 5th light, it’s only a couple of minutes until the green light should turn on. Once its green, it can stay there as long as you want. I’ve had it sit for days on my cars. It should look like this.

Step 8

Open the door, unplug the cigarette adapter, and put the cigarette lighter back where it belongs. Remove the cord from the car and lock it back up. Unplug the CTEK and put it where you store it. Manual says unplug CTEK first.

I hope this helps somebody. YMMV. You’re on your own.

 

Charging via the cigarette lighter (assuming you have the lighter).

I try to be careful handling the unit and not pick it up or carry it by the cords. Over time, they can break. Lesson Learned. In the following pictures, this 4.3 is almost 5 years old. It works fine. Follow at your own risk. The downside to this is if there is a power outage, then the charger should not restart. Caveat Emptor. The upside is that its simple, trivial to get the hang of, and unlike the hood, the doors are probably designed to be opened and closed many, many more times than a hood.

Step 1

Turn the key to accessory position. The car wakes up.

Step 2

Remove the cigarette lighter. Put it in that tiny ashtray so you don’t lose it. Makes sure the plug is pushed all the way in for good contact. Sometimes people complain about a loose connection. I suspect they just didn’t get a good initial connection.

Step 3

Run the wire across the driver seat toward the door. Here, the cigarette plug is connected to the 8’ extension.

Step 4

Run the cord out the bottom of the door. I know this might freak somebody out who might wants to run it out of the window but the door has a rubber piece on the bottom that you can’t see. It doesn’t seem to harm the car or the wire and the door shuts. But, do whatever makes you happy. If your worried about it crimping or harming the body, then figure out some other way to get the cord out. This is also a good reason to use the 8’ extension. If you damage the extension, it cost maybe $11 for a new one. If you damage the actual cord, you probably need a new charger.

Step 5

Plug in the CTEK. Make sure the correct lights are on. It should move to the third light very quickly. If you get an error, figure out why.

Step 6

Turn the engine off. If it’s a real key, remove it. Close and lock the door

Step 7

This is my experience. The first 3 lights should turn on quickly. According to the manual, the unit does not go to the fourth light until the battery is 80% charged. It could take, per the manual, up to 20 hours. If the lights sits at the 3rd light for a long time, I think its telling me the battery is run down. I like to see it go from the third light to fourth within no more than 10 mins, which tells me, with no proof, that’s the battery is really no more than 80% discharged. At the fourth light, it’s just patience. It’s supposed to take no more than 10 hours. Once it moves to the 5th light, it’s only a couple of minutes until the green light should turn on. Once its green, it can stay there as long as you want. I’ve had it sit for days on my cars. It should look like this.

Step 8

Open the door, unplug the cigarette adapter, and put the cigarette lighter back where it belongs. Remove the cord from the car and lock it back up. Unplug the CTEK and put it where you store it. Manual says unplug CTEK first.

I hope this helps somebody. YMMV. You’re on your own.

I found out what my problem was when charging using the cigarette lighter plug adapter. It didn't seem to fit snug and after comparing it to the picture in the owner's manual on page 106 the CTEK adapter also doesn't look the same. I can move it around in the socket to make it work. This was the only one offered by CTEK so it has to be the correct one.

Thanks again for the detailed write-up!

 

Grim...good information but I have a question about this process. To help keep my battery charged I use a CTEK 4.3 and place it in snowflake mode and use the cigarette lighter plug. Everything seems to proceed through the charging process as you described except at the end. I go out the next day to check the results and notice no lit lights except for the power light is flashing green. The instruction booklet doesn't mention this so maybe someone on this forum can explain. I notice my car is fully charged when I take it out for a drive so it much be charging the battery.

 

I don't have that model and I got conflicting info online, ranging from no connection, reconditioning mode to battery voltage too low to charge (<2.2v). Why not contact CTEK? They have any models and several with similar names. The many different models may be causing some confusion here.

To check if your battery is fully charged just unplug the charger then plug it back in. It should cycle through the charging sequence indicator lights pretty quick if fully charged.

 

Grim great job putting this post together. It should be really helpful to new and old owners. Good point about opening and closing the hood vs a door. Didn’t consider that. I’ve been using the socket in the cargo area on the driver side. I’ll be giving the socket at the bottom of the rear center console a try to see if turning the key to the accessory position also wakes up this socket and keeps it “hot”. It’s works with the cargo socket.

Just a couple of comments:

1. The MSX 5.0 charger has a specific reconditioning program for AGM batteries. You just need to cycle through the Mode button until both the AGM and reconditioning indicator lights are selected and lit.

2. The MSX 5.0 model does not seem to have any issues restarting after a power outage. It stays in the same mode it was in at the time power is lost. I simulated a power outage by just unplugging the charger (from the 110v AC wall outlet) for an hour or so after it had been charging for a couple of hours. The cargo area socket stayed hot during the “power outage” and continued charging after the charger was plunged back into the 110v AC wall outlet. I think I’ll do another test to see if the cargo or rear console 12v outlets stay hot after maybe an 8-10 hour “power outage”. [Edit I'm wrong about the rear console outlet, Its just USB ports. Sorry, new owner error, never looked close]

 

1. The MSX 5.0 charger has a specific reconditioning program for AGM batteries. You just need to cycle through the Mode button until both the AGM and reconditioning indicator lights are selected and lit.

OP was corrected. I see your right.

2. The MSX 5.0 model does not seem to have any issues restarting after a power outage. It stays in the same mode it was in at the time power is lost.

The issue isn't with the unit. The issue is the socket. The cigarette lighter, from people's experiences, seems to go back to sleep. Are you saying the cargo socket is always hot, never shut off?

I go out the next day to check the results and notice no lit lights except for the power light is flashing green.

I see at least two references that this means its sleeping, no connection to the battery. The first is the latest version of the 4.3

https://www.amazon.com/CTEK-5PK748190-Silver-Automatic-Charger/dp/B00GODGN9E/ref=cm_cr_srp_d_product_top?ie=UTF8

and the latest manual says the same thing, as well the 5 Amp manual.

https://cdn.shopify.com/s/files/1/0117/5237/4372/files/MUS-4.3-TEST-and-CHARGE.pdf?7329607522301633849

I can easily imagine the original 4.3 behaved the same way and its not in the manual.

This does NOT necessarily mean the poor connection is at the connection point. It only means somewhere along the connection something isn't "connected". My first 4.3 died. I did not treat it gently. I'd pick it up by the wires, and place it down by the wires. It lasted about 6 - 7 years. One time I came out and it wasn't doing anything, no light lit. I jiggled the wires and the lights started to work. I can't remember if the green light was flashing or just on. It started to work. Next time, it did the same thing. It had nothing to do with the cigarette plug or the direct connection I had to the 911.

So, I tossed it and bought the current one I have. I'm pretty sure the wires inside the insulation near the based of the unit coming out were breaking and jiggling them caused an intermittent connection. Maybe this is your problem?

I am planning to permanently attach a CTEK direct connector adapter so that I can charge with the bonnet (hood) closed.

Since there is no easy way to get to the real battery in an emergency to jump the car, the only way to jump it is from those terminals under the hood. Whatever you do, I would not make it impossible to get big alligator clips from cables or Jump Pack onto those bolts.

If you use eyelets on the original bolts, they will flop around, IMO not good. They have to be screwed down tight. But then you can't really get alligator clips on there. I would not give up the ability to jump start the car. I'd like to see your solution.

 

Don't have my Macan yet, but am wondering how soft those bolts are under the hood. Could you drill and tap them or ? Would still keep the original bolt for alligator clips, but would allow a screw to be attached and then an eyelet.
Otherwise I think I will be hooking up leads to the battery in the rear and keep the wire protected under a trunk tray. I do this today with my F-Type.

 

Otherwise I think I will be hooking up leads to the battery in the rear and keep the wire protected under a trunk tray. I do this today with my F-Type.

Watch the video above around 2:30. You can't unscrew the bolts to the battery to get an eyelet around, and then tighten them back down. They are not meant to come apart. I guess you could cut the circular eyelet and make it into a U shaped connector and tighten it down but that kind of jury rig was not meant to be.

Even if you could get the eyelets on, the wires are about 13.5". Spread that across the width of the battery ~27", I doubt you can get the end of the connector out of the bottom of the floor. You probably need the 10' extension.

Good luck. please show pix if you do it.

 

Grim,
Thanks much for the comprehensive write-up, very much appreciated and needed. After reading all the various threads it was a bit confusing as to which C-Tek and its operation. You managed to simplify it all!
Cheers! ?

 

I am hoping this will help anyone who is planning on running your charge plug from the battery posts under the hood to the outside of the car so you can charge with the hood closed.

I ran the charge plug for my Ctec 7002 out under my left turn signal. Not noticeable and easy to plug into with the hood closed.

I chose the left turn signal because there is plenty of room to run the wires up along the fender up to the positive and negative posts.

I ran the positive wire into the exiting joint of the rubber seals, then under the plastic to the brake fluid reservoir and then over to the Positive post.

I used the threaded hole of the positive terminal. Again l used a ring connector and screwed it down using a low profile crown bolt. I can close the plastic flap with no issues.

I unscrewed the negative post and placed a ring connector under it- then screwed it back down.

 

I use CTEK MUS 4.3 & it works great in the rear seat 12V socket. I do turn key on & then off b4 connecting it. I think the CETEK MSX 5.0. is the replacement for the MUS 4.3. If I were to be buying a CTEK now I think I'd get the 7002 so I could use it to supply power when changing out a car battery. The MUS 4.3 & probably the 5.0 cannot supply power with battery disconnected.

 

Guy88 is correct-- the positive post's thread is an M8 x 1.25-- very common. The negative post I believe is an M6 x 1.0- will confirm.

I simply ran 14 gauge (15 Amp) stranded wire which I had crimped on ring connectors from the posts and spliced/soldered in the common two-pin charger pigtail with a 7.5 amp fuse, which I slipped through a space under the left turn signal.

Tidied up with cable cover and zip ties.

 

I cannot remember my C-Tek model....
But- it has a lineup of 6-7 little lights indicating the state/sequence of the charge

I hard wired a pigtail to the battery....
bought the connector cord and extension

I plug it in and feed the wire thru the rear window or just close the trunk on it

I drive the car about 4-5 months / year in total when I'm in the USA

Has worked fine for me this last year.
A 2016 'S' ......

My Indy did the hard wire

Car is currently parked & plugged

 

I just retrieved my car after 5-6 weeks of hibernation.... all good

My unit is a '5'....8 little lights .....

It is on an extension cord / using the C-Tek 10 ft extended range wire.

 

Just bought a CTEK MUS4.3 to charge up my 2020 S, which mode should I use? Snow flake or regular battery mode?
I connect it directly to the charging posts under the hood. When I selected battery mode, stage 4 lights up, when I used Snow flake mode, stage 6 lights up.

 

I experienced the same thing with a new Ctek MUS4.3 Test & Charge. The problem is you need to have both Regular Battery and Snowflake selected (lit) at the same time. Press mode until you get to Regular Battery but keep pressing Mode (don't lift) until the Snowflake lamp lights. It's not explained what the charger is doing with just the Snowflake lamp lit. The user manual is not very clear on this.

 

https://cdn.shopify.com/s/files/1/0117/5237/4372/files/manual-mus-4.3.pdf?7329607522301633849

Snowflake is for cold conditions and AGM which your Macan has. Page 8 of manual.

 

Correction made to OP. I assumed that MXS 5.0 meant 5 Amp. It does not. It is 4.3 with more features. CT5 is 5 amps.

 

Thank you very much for starting this thread, which is incredibly helpful.

I realize that I am responding to a 5+ year old post. Please note that none of the Ctek units are 5.0 amps: Charger selection chart

I actually did not trust the chart above and manually went through all their units on the website and looked at their technical specs. There are a couple of different versions of CT5, but they are all 4.3 amps.

 

I plugged in the CTEK 4.3 on my 2020 S for more than 10 hours, it is still on stage 6 this morning. Can’t believe 3 months old battery can be running this low. Make me wonder if it is really working on newer model?

 

Last night I plugged in my MXS 5.0 on my 2015 SD and it reached stage 7 in a couple of hours!

 

My knowledge of the CTEKs is definitely old. I haven't bought one in five years and even then, I just got a new 4.3 to replace the old one I broke. So I looked closely at the offerings and the 4.3 is gone. The cheapest one now is the MXS 5.0. This is still 4.3 Amps but gives you new features like some kind of "enhanced flood batteries" plus recondition AGM. With a price increase, of course.

Next up is the Polar 4.3, also 4.3 Amps, good to -22F vs -4F. Looks the AGM is charging at 15.0 vs 14.7

Moving up is the CT5 that is 5 Amps. It shows you, roughly, the hours to finish charging but know what step you are in.

Then paying more money gets you the 4.3 Test & Charge, 4.3 Amps, Looks like it also charging at 15.0 vs 14.7

And finally the 7002, 7 Amps, but gets you the benefit of acting as a power supply as needed.

If I did not have one, the cheapest way to go is MXS 5.0 but the 7002 has to be faster, but I think its the oldest one among them. IOW, no new fancy things like an alternator tester.

 

In another thread, it was mentioned that if you select alternator voltage as one of your MFD main screen choices, you can see the actual battery voltage, in addition to the alternator charging voltage.

Later, this was further explained. You must not start the car to see battery V, just turn ignition to the on position. If you start the car it just reads Alternator charging V. This turn out to be true. However, is the battery voltage resign on the MFD accurate?

I tested.
Short answer...NO!

I had just driven my Macan the day b4 & checked MFD battery V. Showed 11.6 V or only ~ 20% charged! How is this possible? I was sure my battery was good. Yes, it is 4+ years old but, I had topped off the charge a month ago & CTEK MUS 4.3 said fully charged & my multimeter had read 12.56 V right after. So, not perfect 12.7 100% but, ~ 95% which is not bad. I checked @ under hood jump start terminals.

So I decided to test the accuracy of the MFD battery V readout, with a fully charged battery, using my CTEK to top off.
Procedure:
Pop/unlock hood
Roll R window down 1” & remove Rear 12V socket plug (do not lose)
Plug in 12V CTEK adapter wi red adapter, + extension cord—flashes red
Connect to charger but do not plug into outlet yet
Turn ignition to On & then to off
Plug CTEK into power outlet
12V adapter now flashes green as car battery begins to charge
Verify CTEK set to Snowflake/Cold/AGM
Lock car -shuts off accessories & interior lights

I checked b4 I went to bed last night & step 4, today < 12 hrs. later it was step 7... done!
I unplug CTEK from power outlet
W/o opening car door to wake computers, I opened the hood... which I had popped/unlocked last night b4 charging.
MM = 12.59 V or ~ 95% charged!
{Note: I had charged to 12.77 V, 3+ years ago when battery/car only 1 year old.}
I suspect 95% vs. 100 % charge due to battery being > 4 years old.

I then check MFD battery V reading & shows 12.1V…~ 50%! Clearly this MFD display of battery voltage is way off! Significantly underestimates true battery voltage.

 

I checked my battery on the display at 12.1v too. Maybe it’s under partial load.

 

Here is my CTEK MUS 4.3 charging procedure on my MY2016 Turbo:

Pop/unlock hood
Roll R window down 1” & remove Rear 12V socket plug (do not lose)
Plug in 12V CTEK adapter wi red adapter, + extension cord—flashes red
Connect to charger but do not plug into outlet yet
Turn ignition to On & then to off
Plug CTEK into power outlet
12V adapter now flashes green as car battery begins to charge
Verify CTEK set to Snowflake/Cold/AGM
Lock car -shuts off accessories & interior lights



I have a garage. I bought the CTEK extension to attach to the 12V adapter so I can have the (HOT) CTEK charger outside the car.

This procedure probably will work regardless of which 12V outlet used.

I pop hood 1st so when charging complete I can ck V with multimeter from underhood jump start terminals w/o having to open door to pop hood & wake up computer & put more load onto the battery drain it a bit.

 

... You must not start the car to see battery V, just turn ignition to the on position. If you start the car it just reads Alternator charging V. This turn out to be true. However, is the battery voltage resign on the MFD accurate?

I tested.
Short answer...NO! ...

W/o opening car door to wake computers, I opened the hood... which I had popped/unlocked last night b4 charging.
MM = 12.59 V or ~ 95% charged!
{Note: I had charged to 12.77 V, 3+ years ago when battery/car only 1 year old.}
I suspect 95% vs. 100 % charge due to battery being > 4 years old.

I then check MFD battery V reading & shows 12.1V…~ 50%! Clearly this MFD display of battery voltage is way off! Significantly underestimates true battery voltage.

How did you check the MFD? You had to open the driver door, which wakes up some things, alarm off, things come to life, then turn the key to the accessory position and all kinds of things wake up. You can actually here pumps moving, fans or something. Does not the PCM turn on regardless of whether the radio sound is on? And the idiot lights on the dash? They are testing something. If you have the lights on auto, the lights will turn on? Did you completely shut the door so the interior lights are off? Etc.

I don't think its as simple as it sounds. 12.1 could be correct if something is drawing current. I don't think there is anyway to determine anything from the MFD UNLESS the car is running and then you know its the alternator doing its thing.

 

I finally figured out how to make it worked. I was in test mode all the time that's why it stayed at stage 6 for 10 hours. You need to push the mode button for 2 seconds to get into the charge mode. After that, I used the snowflake mode to charge my battery, 6 hours later, it's green light and fully charged.

 

Yes, I woke the computer up to check the MFD, as described after I charged battery & checked battery V using MM under hood w/o waking you car. No way is my battery V going to drop from 95% to only 50% charged by simply turning key to on. I don't buy it.

Someone (not me) Can test this by checking battery V @ jump start or actual battery terminals & then with MM still connected, open door & turn ignition to On & check MFD battery V. If they read 12.1 & then the MM, which 2 minutes b4 had read 12.7, now DROPS to 12.1... agreeing with the MFD, I will be astounded.

 

I think the MFD shows the alternator voltage not the battery voltage. I used to see 14.5V on MFD while driving, after I fully charged the battery this weekend, today on my way to work, it showed 12.1V all the way. Looks like the system detects the battery status and sets the alternator to the lower voltage to avoid over-charged the battery.

 

We’re talking with the engine off, key in acc position.

 

MFD with ignition on but car not started is NOT the alternator Voltage. Explained several times above in this thread.

Re MFD display of battery V...I wonder if it will typically show ~ 12.1V (50% charged) when you have a fully charged battery?

In any event, I think MFD display of battery voltage is wrong & therefore completely useless.

One caveat, I don't think checking battery voltage, via MFD, is listed in any Porsche owner manual. Maybe we are wrong & it is NOT intended to show battery V with ignition set to on but car not started. We are assuming this is true.

 

...
One caveat, I don't think checking battery voltage, via MFD, is listed in any Porsche owner manual. Maybe we are wrong & it is NOT intended to show battery V with ignition set to on but car not started. We are assuming this is true.

Let me put it this way (and this is not meant in a rhetorical or smartaleck vein): where do you think the MFD comes up with that number -- 12.1, 11.9, pick a number, any number -- when you turn the key to the accessory position?

I'm asserting that it's not a random number, i.e., the MFD is reading some voltage. That it doesn't match what you -- a bit earlier -- measured at, say, the jumper posts does not surprise me. Of course, there will be slight discrepancies based on the accuracy of any voltage reading device, but more importantly you've also fired up the inside or outside lights and who knows what else, when turning on the car. I've done this -- accessory only -- and watched the MFD readout drop a bit, as the seconds go by.

What I think you should do is connect a volt meter to the posts with long leads, so you can watch, from inside the car, what the meter's readout is saying, while also watching the MFD readout in the accessory position. Maybe I need to do this myself, with a little GoPro action, as another one of my Macan-based science projects.

 

How long does it take to charge the car?

I know it depends on many things, just wondering. And with which charger, 4.3 or 7 amps?

 

Performed Science Experiment

Okay, sportsfans, I spent some time with this last night and this morning.

First, I cobbed up some long leads for one of my multimeters. I used some extension leads with SAE connectors that I had lying around in my miscellaneous electrical box, snipped off the pointy probes from a multimeter* so I wouldn't have to deal with them, and used a couple of Posi-Locks. Here's what that looked like:

* (Don't wince at my butchering the probe leads. This is a Harbor Freight cheapie (7 Function Digital Multimeter), and as a consequence of HF's offering them gratis, with coupon and any purchase over the years -- I'd get some cable ties or a roll of electrical tape, as there's a store about two miles away -- I have accumulated a couple dozen of these:

Besides having spares, I give them away to an experimentally inclined 12-year-old who lives next door, whenever he breaks one.)

Okay, back to the experiment.

I did that wire-stripping, etc., last night. I also did some trial runs of different methodologies last night, without starting the car, which probably didn't do the battery any favors, but c'est la vie.

In any event, I finalized(?) my test runs this morning, and here's the sequence of what I did:

1) Hooked the meter up to the jumper posts under the hood, and turned the meter on.

2) Carried the hooked up meter Into the car, mounted it with a vent-phone-holder next to the MFD, turned the ignition to the Accessory position, and observed for a while.

3) Opened the garage door with the HomeLink button (at c. the 43-second mark).

4) Started the engine, and closed the car door. (I had hoped to compare the MFD's alternator output readings with the multi-meter, but the MFD display just showed that the hood was open, and, unlike the door, I didn't want to close the hood on the leads. Oh, well. If this is really important to someone, I leave it as an exercise for the reader.)

5) Turned off the engine, all the way.

6) Put the ignition in the Accessory position again, and observed some more.

7) Got out of the car, and watched the meter, while the inside lights, taillights, etc., went out.

Some background notes:

A) This was done with our '18 S, which is now c. 27 months post delivery, and has 37,000-something miles on it. And because it's our daily driver, it's never been on a charger.

(I have a couple of PulseTech Xtremes -- XC100-P Xtreme Charge 12V Battery Maintenance Charger Desulfator -- for my motorcycles, etc. I've used them on our Camry, and it's probably time that I put one on the Macan, if it will be unused for a day or so. BTW, PulseTech talks a good game -- desulfation and suchlike -- on its web site. They have no switches to set, but I don't know whether that's because they're really sophisticated, and so figure out a battery's needs by themselves, or not really sophisticated, using a one-size-fits-all approach. They seem to do an excellent job vis-a-vis the bikes and my riding lawnmower.)

B) As I said, that HF meter is probably a far cry from a $200 Fluke or something like that, but I can't find the specs anywhere. They seem to work fine to me, yield repeatable results, and so forth.

Also, there has to be some voltage drop across my long-lead fabrication. Each lead is about eight feet, from meter to alligator clip, of, I think, segments of 14- to 18-gauge wire.

The Results:

If you have two minutes and fifteen seconds to spare, here's an expurgated video of those sequences I described above:



(If the embeddedness doesn't work, because of some security conflicts, or pop-up blockers, etc., you can just put vimeo.com/388249756 into your browser's URL field.)

Some observations on that:

- The under-hood-only battery reading could be a little higher, certainly. As I said, maybe it's time to let a PulseTech have its way with the battery for a day or so (it took about that long on the Camry, every year or so; on my smaller motorcycle batteries, I plug in after coming home from a ride, and it takes about 10 - 15 minutes to go to its float state).

- The MFD reading does change during the testing, dropping down 0.1 VDC at times. Thus, for instance, it doesn't just take a single snapshot of the battery when you use the Accessory position. Instead, it seems to be an active readout.

- Further, the MFD seems to read roughly 0.3 VDC higher than the meter, and they seem to move in sync. As I say, those leads were long, and also I don't know the accuracy specs of the meter. By the way, you may notice that I had the meter set to its 0 - 20 VDC scale, i.e., it was optimized for this test.

That's my story. You may have your own interpretation of all this, certainly, but to me it indicates that the MFD voltage display, with the ignition in the Accessory position, is actively displaying the battery's voltage output more or less in real time.

That's all I got.

 

Performed Science Experiment...
...First, I cobbed up some long leads for one of my multimeters. I used some extension leads with SAE connectors that I had lying around in my miscellaneous electrical box, snipped off the pointy probes from a multimeter* so I wouldn't have to deal with them, and used a couple of Posi-Locks. Here's what that looked like:
...

Thanks for doing this.

Would you please do this quick and easy test?
1) Again use your long lead MM to check battery voltage @ the under hood jump start terminals & then disconnect it.
2) Get your standard (short lead) MM & recheck V.
Are the readings the same?

If so, you proved that the long leads did not adversely affect the accuracy of your MM.

Your MM readings seem to show that your Macan battery is only ~ 30% charged! (See my posted voltage chart above)

Will a 92Ah battery @ only 30% charge still starts the Porsche Macan? IDK. If you MM readings are correct the answer is YES!
Surprising.

I have charged my Macan battery measured with MM @ under hood battery terminals to 100% several times & recently to 95% charged.

The idea that "My battery is fine" or "Never gave me any trouble" based on the fact that it has always started the car, while a common sentiment, is not really an indication of battery health. I'm sure every stranded motorist with a dead battery thought just that... until it failed to start the car.

I think the reason so many Macan owners are interested in this thread about charging & replacing the Macan battery is many of us do not wish to pay Porsche $700-$800 to replace our batteries when they fail bc we think it is a rip off when a great AGM battery of = or > specs can be purchased for $150-$300.

 

I was reading this thread and maybe I am not following the issue that is being addressed here. I have a 15 S with 44k miles so I don't drive that much. My office is less than 10 miles from my house so many times I don't have a chance to warm the car enough. I live in MN and we get temperatures of -30F sometimes and below 0F for a good 4 months/year every single day. My point here is that not a single time I had any issues with the battery meaning I always turned the car and the car started immediately. I did replace the battery after 4.5 years but because my SA said it was running low although I never experience any issues. I simply followed his recommendation. Thus, why are you guys buying all these stuff to charge the battery? Are you experiencing issues way sooner than expected?

 

As outlined in the original post, Porsche's new car warranty implies that a battery maintainer be used on cars driven less than 6000 miles per year. Since your car is out of warranty it's not as much an issue. I haven't owned my Macan (2018) long enough to experience a failing battery but if it fails during the warranty period I want to have satisfied Porsche's requirements.
I do have a 16 year old Mercedes that has exhibited problems as the battery ages. Even though the car starts fine other issues would pop up, like the headlight leveling system getting out of whack and sensors throwing false malfunction messages, etc. Also using a maintainer extends battery life.

 

Who has a relatively new Macan with a new battery? Just turn the key to accessory (turn on accessory but not crank the engine) to see if the battery voltage display shows around 12.1v.

My 5-year old battery shows 12.1v.

 

My 3.5 says the same 12.1v (fan off).

14.3v once started. Bar level shows 75%. One bar away from full.