mtgadbois

Okay all you electronic wizards tell me why. I have 2 Ctek, models 3300 and 7002, battery chargers. Both battery chargers/maintainers have selections for charging mode and readouts of the battery charge level. If I connect either Ctek unit directly to the battery I get a readout of current battery charge. If I connect either Ctek unit through the cigarette lighter I get no readout of current battery charge. I know the cigarette lighter is hot because the lighter will operate. Any ideas out there? I also see that Ctek now offers a cigarette lighter adaptor with 3 led’s for battery charge level. For those of you if you have the Porsche branded unit and you connect through the cigarette lighter does it show battery charge level? FYI, for my 991 I now have the ring adaptors connected to the battery and have fed the connector out the window washer spray hole and then have connected it to my Ctek. Works just fine and I do not need to leave a window slightly open or worry about pinching the cable in the door.

CSK 911 C4S

Just guessing that a direct connection to the battery the chargers are sensing full battery power plus full amps where a lighter socket circuit is limited and fused plus it probably goes through some type of computer in the car.

For me on trickle charged vehicles the only way to connect is direct to the battery.

If you have multiple vehicles on trickle one of these bad boys really does the job very nicely.
http://www.batterytender.com/Charger...emisphere.html

JAM2

My Porsche branded battery tender when plugged into the cigarette lighter did not show a readout. However when plugging it in and my 997 into the lighter by the subwoofer it shows a readout.

titleistaddict87

This may be an obvious question but does this mean you leave your window open a crack for the cable to go out to the wall plug?

Powereng

Not sure if you are using both terminals on the battery when charging but I seem to remember that you should hook the negative line someplace other than the battery negative. I believe they want you to use the little post that sticks up near the windshield wiper arm. I use the cig lighter in center console and works great.

Porsche_nuts

I think this is only if you are jumping the car - don't think such is necessary when putting a trickler on.

pvr

No - I let the wire go high next to the side of the glass where it joins the rubber, the cable can still be moved when the door is closed without problems.

Powereng

Check your manual, my manual says to only use the emergency starting terminals to charge, you can find this on page 248

mtgadbois

Page 248 in my manual is Cleaning things and Storing Your Porsche, nothing related to this. Page 285 deals with Jumper Cables etc. Yes, in that case when you are jumping a dead battery your quick charging maybe freeing up some O2 which in proximity to a spark can cause a big bang. In that case you want to connect your second cable well away from the battery. That is why Porsche and other manufacturers have a negative post some distance away from the battery.

The reason I brought this whole topic up was I had a problem figuring out how the battery charger would dial back its power when the battery becomes fully charged if the charger could not indicate that the battery was fully charged. I do not think there is a problem but maybe the float voltage being supplied is less than the voltage necessary to fully charge the battery. In my case it really doesn't matter anymore since I am wiring directly to the battery and the routing of the cables is such that it does not require the door to be open or the rubber seals to be "dented." In the past week I had my charger connected via the cigarette lighter and no battery charge level lights were lit. When I moved it to be directly wired to the battery I was able to see the battery charge levels and it did take several hours of charging before the battery was "fully charged."

Powereng

You still may want to contact Porsche before going directly to the battery, there are post on this forum that discuss this exact topic and if you look up charging your battery, see if it says to go straight to the battery plus if you go to the Porsche good to know app and use battery, you will see charging and read that, but hey, it's your electrical system.. Good luck.

Duke I

I use the passenger footwell power plug and get the indicator lights on my CTEK. I Run the cord up through the bottom of the door -- with a loop over the shifter as a polite reminder of the connection. Haven't noticed damage or permanent compression of the multiple door gaskets.

GrandLaker

I have the Ctek 3300 and connected to cig lighter it definitely shows battery charge state.

mtgadbois

Grandlaker - thanks!

I'll play a little more with my 2000 Boxster and try its cigarette lighter. The 991 is a 2016.

Porsche_nuts

Thanks Power - I reread my reread my trickler instructions and redid my wiring. Good looking out!

mtgadbois

Solved I think. I connected to my Boxster's cigarette lighter and found no change. I decided to meter (VOM) the Ctek cigarette plug and found that the positive side was open. Took it apart and there is a small ceramic fuse inside and it was blown. Strange since I bought it new on Amazon and never used it until this year. Too bad Radio Shack is gone. Anyhow it is near 50 in Chicago and the car might as well come out and see the sun.