Ctek on a 987 - confused - Page 2 - Boxster/Cayman - PistonHeads UK

I have been neglecting my poor 987 and had a Ctek on the shelf in the garage so thought I may as well hook it up. I have read that if you connect a conditioner directly to the battery terminals it can confuse the battery monitoring stuff in the car and it's better to use the earth post for the negative. I tried to do it last weekend and realised the eyelets I have with the Ctek are too small to go over the earth post next to the battery. But then the battery terminal seems to be connected to that same earth point anyway, so is there any point in connecting the Ctek to the earth instead of the negative terminal? Or can I just connect it to the battery clamps like I would on other cars? Ta in advance etc

tomtom said: I have been neglecting my poor 987 and had a Ctek on the shelf in the garage so thought I may as well hook it up. I have read that if you connect a conditioner directly to the battery terminals it can confuse the battery monitoring stuff in the car and it's better to use the earth post for the negative. I tried to do it last weekend and realised the eyelets I have with the Ctek are too small to go over the earth post next to the battery. But then the battery terminal seems to be connected to that same earth point anyway, so is there any point in connecting the Ctek to the earth instead of the negative terminal? Or can I just connect it to the battery clamps like I would on other cars? Ta in advance etc I also have a 987 on a Ctek, connected to both battery terminals and never had any issues to date.

Don't you have crocodile clips as well as the eyelet contacts ? I have used both methods with no problem ... but I was told that using the negative contact on the chassis ensures that the ECU can see the full history of the battery which may make a difference to its performance ...

Sandy59 said: I also have a 987 on a Ctek, connected to both battery terminals and never had any issues to date. Me too, no issues over several years

tomtom said: I have read that if you connect a conditioner directly to the battery terminals it can confuse the battery monitoring stuff in the car and it's better to use the earth post for the negative. Is the recommendation not to confuse the battery monitoring primarily for cars with stop-start?

tomtom said: I have been neglecting my poor 987 and had a Ctek on the shelf in the garage so thought I may as well hook it up. I have read that if you connect a conditioner directly to the battery terminals it can confuse the battery monitoring stuff in the car and it's better to use the earth post for the negative. I tried to do it last weekend and realised the eyelets I have with the Ctek are too small to go over the earth post next to the battery. But then the battery terminal seems to be connected to that same earth point anyway, so is there any point in connecting the Ctek to the earth instead of the negative terminal? Or can I just connect it to the battery clamps like I would on other cars? Ta in advance etc No there isn't. As you rightly said, the earth point is connected directly to the battery. As will all other earth points around the car via the body shell.

If you have an older type Porsche battery remember to check the fluid levels in each cell, there is a level marker inside so its dead easy.

Thanks guys. ChrisW. said: Don't you have crocodile clips as well as the eyelet contacts ? I have used both methods with no problem ... but I was told that using the negative contact on the chassis ensures that the ECU can see the full history of the battery which may make a difference to its performance ... I do have crocodile clips but I prefer to use the eyelets and the convenience plugs. It saves a bit of time and hassle when wanting to drive the cars.

I plug my CTEK straight into the 12v inside the car (987.2) and no problems charging the battery whilst being very convenient to remove and drive.

Doddler said: I plug my CTEK straight into the 12v inside the car (987.2) and no problems charging the battery whilst being very convenient to remove and drive. Does anyone know whether this works on a 718. I’ve just got a ctek mxs 5 with the cig lighter adaptor and unsure whether irs working or what setting I need it on. Any ideas?

Maybe buy some bigger eyelets - CTEK do many sizes.

alscar said: Maybe buy some bigger eyelets - CTEK do many sizes. Yes, I was hoping to avoid that

rwillia2 said: Does anyone know whether this works on a 718. I’ve just got a ctek mxs 5 with the cig lighter adaptor and unsure whether irs working or what setting I need it on. Any ideas? On my 981 you have to put the ignition on, then turn on the charger then turn ignition off then lock the car. Don’t quote me but I believe it’s something to do with keeping the 12v live when starting the charger up. I have been using this method for 2 years and it works well.

Cw4578 said: rwillia2 said: Does anyone know whether this works on a 718. I’ve just got a ctek mxs 5 with the cig lighter adaptor and unsure whether irs working or what setting I need it on. Any ideas? On my 981 you have to put the ignition on, then turn on the charger then turn ignition off then lock the car. Don’t quote me but I believe it’s something to do with keeping the 12v live when starting the charger up. I have been using this method for 2 years and it works well. It didn't work on my 981 Spyder had to hard wire it on to the battery with the neg earthed onto the tower strut on the side. Loads of threads on this topic like here https://www.pistonheads.com/gassing/topic.asp?h=0&...

Cw4578 said: rwillia2 said: Does anyone know whether this works on a 718. I’ve just got a ctek mxs 5 with the cig lighter adaptor and unsure whether irs working or what setting I need it on. Any ideas? On my 981 you have to put the ignition on, then turn on the charger then turn ignition off then lock the car. Don’t quote me but I believe it’s something to do with keeping the 12v live when starting the charger up. I have been using this method for 2 years and it works well. ^^^^ this on 718 too

freedman said: Sandy59 said: I also have a 987 on a Ctek, connected to both battery terminals and never had any issues to date. Me too, no issues over several years Ditto above on 987

boitjie said: ^^^^ this on 718 too Daft question but how do you know if it’s working/charging?

Thanks all, finally got round to hooking it up to the terminals yesterday. rwillia2 said: Daft question but how do you know if it’s working/charging? Daft question back at you - is your username a hangover from your university network username at Sheffield Hallam? I was given an almost identical username during my very short time there and still occasionally use it. I had to do a double-take when I saw your username.

rwillia2 said: Doddler said: I plug my CTEK straight into the 12v inside the car (987.2) and no problems charging the battery whilst being very convenient to remove and drive. Does anyone know whether this works on a 718. I’ve just got a ctek mxs 5 with the cig lighter adaptor and unsure whether irs working or what setting I need it on. Any ideas? In my 718 Boxster I just plug it into the 12v socket in the passenger footwell and carefully shut the door leaving it happily charging away. I’ve never done anything with turning the ignition on/off etc. I position the Ctek where I can see it so I know the state it’s in.

rwillia2 said: boitjie said: ^^^^ this on 718 too Daft question but how do you know if it’s working/charging? Daft reply .... Because I used it last Friday to charge my battery .... and the indicator lights say it is charging Edited by boitjie on Monday 28th November 09:04

a tip if you use the O ring connecters cut a small nick out of them to form a C that way you do not need to remove clips from battery with the potential of losing codes, just slacken off connector and slip in .I have the 981 and no issues using the + and - to connect up during layup. the 987 I use Lidl croc clips no issues over 10yrs .

Or just buy the M8* connectors at a bargain £4.99 https://www.amazon.co.uk/Ctek-CTE-56261-Direct-Con... * IIRC In terms of connecting to the negative on the battery itself vs the negative connection point I believe the 981 and 718 have a battery management system so it does make a difference and should not be directly connected to the battery negative. On the 987 I'm not so sure it matters.

anonymous said: [redacted] Me neither, not on my previous 981 CS or current 981 GT4. No ignition on/off, lock the car blah blah. Connect the charger leads, +ve to the battery, -ve to the suspension post. Connect the charger, shut the frunk and start charging.

HighwayStar said: Me neither, not on my previous 981 CS or current 981 GT4. No ignition on/off, lock the car blah blah. Connect the charger leads, +ve to the battery, -ve to the suspension post. Connect the charger, shut the frunk and start charging. Thanks, but your answering a different question, I was specifically asking about the cig lighter method. I don’t really want to faff about with taking the cover off and connecting to the battery.

rwillia2 said: Thanks, but your answering a different question, I was specifically asking about the cig lighter method. I don’t really want to faff about with taking the cover off and connecting to the battery. It's a lot easier than you think. And hardwiring removes any uncertainty that the cigarette lighter socket has shut off (which some do).

(718) Just received my cig lighter adapter today . Plugged in without doing anything 3hrs ago and still seems to be charging .

rwillia2 said: Does anyone know whether this works on a 718. I’ve just got a ctek mxs 5 with the cig lighter adaptor and unsure whether irs working or what setting I need it on. Any ideas? It works on my 2022 GT4. I leave my MXS5 permanently connected to the mains. When i have finished using my car, I turn off the ignition and remove key, connect the ctek via the cigarette adapter to the power socket (I use the one near the armrest, part of the smokers pack) and then the charge lights on the ctek start illuminating, so you know it’s charging. I then shut the drivers door and lock the car. I use one of the ctek extension cables to make it a bit easier. This process also works fine on my 981 Spyder.

rwillia2 said: Thanks, but your answering a different question, I was specifically asking about the cig lighter method. I don’t really want to faff about with taking the cover off and connecting to the battery. No worries… it’s literally 5min one time job. Connector pokes through the slot in the cover and that’s it. It never has to come off again. For me, better than have the charger lead shut between any seals.

philj said: It works on my 2022 GT4. I leave my MXS5 permanently connected to the mains. When i have finished using my car, I turn off the ignition and remove key, connect the ctek via the cigarette adapter to the power socket (I use the one near the armrest, part of the smokers pack) and then the charge lights on the ctek start illuminating, so you know it’s charging. I then shut the drivers door and lock the car. I use one of the ctek extension cables to make it a bit easier. This process also works fine on my 981 Spyder. Yep same for me on ‘22 GT4

718 GT4 RS - I use the passenger footwell socket and the cigarette lighter adaptor - the cigarette lighter in the centre console didn't stay live when the car was turned off and locked. No issues when using the passenger footwell socket.

HighwayStar said: No worries… it’s literally 5min one time job. Connector pokes through the slot in the cover and that’s it. It never has to come off again. For me, better than have the charger lead shut between any seals. Absolutely the best way of connecting the CTEK.