996 Charge-O-Mat (trickle charger / battery maintainer)

I have a Porsche charge-o-mat (trickle charger / tender charger / battery maintainer) which connects to the cigarette lighter of the car (996.2).  My problem is that it doesn't seem to be able to charge/maintain the battery when the car is off (i.e. ignition lock position 0 and key out of the ignition).  This is because the cigarette lighter circuit appears to be cut when the ignition is in position 0. To get the charge-o-mat to charge / maintain the battery, the ignition needs to be in position 1.  While i can understand why the power/circuit is cut to the cigarette lighter at ignition lock position 0, i don't understand how Porsche had intended the charge-o-mat to work if you need the key to be inserted and turned to position 1 to charge/maintain the battery. Does anyone know if there is a way to keep the cigarette lighter active when the ignition is in position 0 and the key is out (for the purpose of using the charge-o-mat)?

It works for my 987.2 Boxster Spyder even when the ignition is off - perhaps the older 996 doesn't allow this. You can get the crocodile clip adaptors which allow you to connect the charger directly to the battery terminals from a dealer - I think they cost about $25. https://www.suncoastparts.com/product/00004320255.html

Thanks Apogee.  I figured this may be required. I was hoping there may a hidden unswitched cigarette power outlet somewhere in the car (i believe the 997s have one in the passenger footwell), or a simple of way of changing the cigarette lighter to be unswitched. I would rather not have to mess around and change the cigarette lighter from a switched circuit to an unswitched circuit.

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Perhaps give the dealer a call to ask if there is an unswitched outlet in the 996, or it maybe indicated in the manual.

Had the same issue on my 996.1. Initially I did the crocodile clips to the battery. I got tired of the process (of open bonnet, unclip, battery cover on) and I was a bit concerned about exposed clips so I had my Pdealer's tame autoelctrician wire the cigarette lighter off the ignition (now always on) and have had no issue since. I did manage to break one of the flimsy plastic spring tabs on the charger insert to the lighter socket. I realised the Navara part is a direct swap. I bought the Navara head from AutoBarn and it was a quick fix. The replacement head has a small LED which gives me comfort that the unit is properly connected. I was getting the lights on the Charge-o-mat (C-Tek) but the charge was not reaching the battery.

Thanks GT3. When you put it like that, it may be worthwhile either changing the existing socket to be unswitched or adding an unswitched socket somewhere in the passenger footwell.  It is just so much easier than having to open the bonnet and unclip the battery cover each time (and the same in reverse when i want to use the car).

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can you then close and lock the door or is the cable too thick to fit between the door and car?

There is supposed to be a notch in the door that allows one to close the door with the cable attached. I just wind down the windows half an inch or so to allow the cable into the car.

Why not install one of these?  Will work with Porsche battery maintainer as it is a Ctek that was rebranded and priced differently. CTek cable

FWIW the cigarette lighter on the 996 MK1 and MK2 is only constantly live in non RoW cars (i.e. US cars). I use the ctek with the same connector 318touring mentioned (came with the c-tek unit), works quite well. The Porsche unit is indeed made by c-tek.

KieranD and D2000 the cable fits well under the door, does not impede closing the door and is not damaged or marked, the Charge-0-Mat cable being flat. Initially it was suggested by the dealer to hide an extra lighter socket under the dash. I am happy to have wired it constantly on. Very easy now.

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My UK 996.1 has live cig lighter with key out