TexasRider

Hi guys. Help me out please.

My new 2016 Cayman S has had to sit a couple of weeks due to the monsoon rains setting in on Houston the past couple of weeks. So no problem as it will start but I went to the dealer and got the Porsche Pro Battery Maintainer.

So I get it home and read it.

I plug it in to the car in the footwell 12V socket and then in to the wall 110Ac and press the mode button until the car battery is lit up and then it errors out with the blinking power lamp.

Hmm ok.

I read in the little instructions to turn the vehicle on and off once if the car had not been stared. So I move the 12Vscoket to the center 12V plug and turn the car on and off. The lights go good , but after a while it errors out.

So now I unplug it and go start the car and let it run 5 minutes. I turn the car off and connect the 12V in to the plug and now the charger in to the wall. I select the car battery in position 2 on the charger again. It says to hold for 10 seconds but the light changes in about 5 seconds. Ok. I hold for 10 anyway. It acts like it is charging but again in about 30 minutes it is in error mode again.

Is there a menu to select to turn on the 12V sockets? I looked all in the manual and couldn't find that.

This car has an AGM battery so they said the Pro is the battery maintainer to use. Surely i shouldn't select the Lithium mode for this battery.

Of course maybe the charger is messed up but it is brand new as of today.

Anyway any tips would sure be helpful. Thanks.

TexasRider

This is the one I am using.


Porsche Battery Maintainer - Pro

TexasRider

It seems to me that the 12V interior plugs are switched off in about 30 minutes.

I have tried it with both the door unlocked and the doors locked. It still times out.

The Porsche dealer said yeah just plug it in. I even asked the service writer too because I figured this might be fussy.

On my BMW you had to put the plug from the charger into the active 12V receptacle. Then turn the ignition on and power up the 120VAC to the charger and plug. Then it would go hot and then you turned off the key. But I see no mention of this in the manual nor the charger instructions in that order.

TexasRider

I am by myself on this one.

None of you guys have had this?

martyp

Hmmm. I'm using a BatteryTender with a hardwired harness in the frunk on a '15 CS. No issues.

I have an interior adapter for the BT. Let me try it and see what happens. I assume you are running the cord through an open window?

TexasRider

I ran the cord through the door sill.

When activated it stays on for about 30 minutes. Then the car shuts the plugs off from what I see. I did cycle the key once and it reset and went on . . you guessed it . . another 30 minutes. Then battery charger lights indicated good at that time. But it isn't much of a maintainer if I have to reset it every 30 minutes. Lol.

I read some on one of the Macan forums about guys that had the same issue and then ones that didn't. Maybe it is a build date thing. Some said the dealer told them it was a 30 minute time period. Others said it was in the manual but I sure haven't seen it. Others said it happens when you lock the car as it turns the power off. I tried it with the car locked and unlocked with the same results.

There were some posts that indicated at least previously the dealer had been able to code the 12V power port to stay active.

I will have my car back at the dealer next week and I intend to sort it out. As I said I had semi expected there to be problems and it was.

Thank you Marty.

martyp

No worries, I was in the garage cleaning guns anyway.

I used the receptacle in the console. I have one there and another in the glove box. Not sure about the foot well. The car here is a late (May) '15 build.

After about 5 hours it's still charging, moving from the less than 90% level to the above 90% level. So I'd say it's working for me.

Do you have another vehicle you can try the charger on? At least to rule the charger out . . .

In any case I'm sure the dealer will help you get this sorted. The maintainer is an important tool for those cars that aren't DDs, or at least during some seasons.

TexasRider

When I kept it on for an hour by cycling the key on and off it ran to the 3rd level (90%) full. So I think that the unit is working properly. The car just turns it off interim to completing the charge ( I think) .

At this time the car is not in danger of losing its battery power. But I don't drive it sometimes for weeks so I want to get it working. Plus I paid a couple of hundred for the "best" charger - with a P on it lol - so I was just trying to get it sorted now. Before I put the key in sometime in the future and get that wawwwww wawwwwww sound or just a click.

Thanks again.

patdonahue

FWIW I have a 2015 Cayman. I use the Porsche battery maintainer that is probably the previous model to yours (purchased in late 2014) judging by your photo. You might want to get the maintainer checked out. If circumstances are such that I cannot drive my Cayman for 2-3 weeks I plug the maintainer into the center console set it up for car battery using the button and plug it into the wall outlet. The amber light comes on showing a charge and when the charge is maintained the green light comes on and stays on until I open the door which activates a battery relay in the car at which point the light goes amber again showing the charging process has renewed. I have never had the caution light come on nor have had to turn on the ignition or anything else to get it to charge. I also run it under the door sill. I have left it connected for more than a week at a time. I also use the same maintainer in my 2001 Boxster S using the same protocols with no problems. Unless something was changed in the cars system for 2016 I am kinda leaning toward the thought that your maintainer may not be up to speed...
HTH, Pat D
BTW I do not use the maintainer immediately after I have driven the car but only if it has not been driven for 2-3 weeks.

TexasRider

The maintainer works. Mine is a 2016 CS.

Porsche has apparently refigured the plugs in the newest build cars or at least in some of them. But I will see in a few days for sure.

TexasRider

To close this out it was exactly as I thought. I had my car back at the Porsche dealer and got the scoop on the 12V plugs and charging.

The newer cars (2016) are set up at the factory and delivered from Porsche to turn off the 12V plugs and power after 30 minutes.

At this time the dealer cannot recode the plug to keep it hot either.

Porsche is apparently working on something for a later time to fix or work around this problem. It is at this time Unknown as to what and when that might be.

And BTW for other thread visitors if you do attach your charger directly to the battery DO NOT ATTACH the lead to the negative post of the battery. Attach it to the grounding lug of the car located there to the right side. The same lug as you would use to jump the battery and start the car.

CountCatula

Thanks TexasRider. I have a 2016 as well and was concerned that the dashcams would drain out the battery as the 12V never shut off. Now what you posted is welcome news but then I'd have to deal with the same challenge you posted for when I don't take the Cayman out for more than a week. FWIW, I have the than you do but it doesn't have a Porsche label on it, so it cost me about half the price

9114s/FNG

Why won't the battery tender 2 is use on my corvette work on the C4S? Juice is juice isn't it?

patdonahue

Hmmm. I wonder why the electrical gurus at Porsche would only let it charge for 30 minutes? This sounds like a retrograde change from the 2015 models, If the car sat for 3 weeks during monsoon season it would take quite a few trips out to the garage to reset the maintainer to get the battery up to full charge. If my car sits for like 2-3 weeks and I plug the maintainer in it takes longer than 30 minutes to top off the battery.
Glad you got an answer, hope they get you a fix ASAP

martyp

Glad you got that answered Rider. In the interim a frunk harness with an easy connector will do ya well, heeding your advice about the ground connection. I just open the frunk, connect her up, and gently close (but not all the way!) such that the latch just engages, leaving plenty of space for the cord - the light in there goes out on it's own after a little while