Flyferrari Posted December 30, 2018 Report Share Posted December 30, 2018 I have a Ctek Multi XS7000 that I use on my 981 GTS when it's not been used for a while. I have fitted a flying lead directly to the positive terminal of the battery and an earth point on the top of the nearside suspension turret. For the most part this works well. However, recently, once the car is fully charged and the charger is in maintenance mode (light on the Ctek goes green) I can hear an intermittent clicking sound (like a relay click) coming from the charger. I contacted Ctek about this and they suggested that this didn't necessarily mean the charger is faulty and I should try to charge another car with it. I haven't had the need to do so recently so don't know what would happen but over the whole Christmas period my GTS was on the Ctek without the clicking. Only after I went into the car to get something (charger cycles from maintenance to charge and then back to maintenance as the power is used by the lights etc.) did the clicking reappear. Does anyone else with a Ctek experience anything similar on their 981? I'm wondering if it's something to do with the smart charging control circuitry built into the negative battery terminal that's causing the "issue". Which brings me to the next question. Is the clicking an issue? Could it damage the cars electrics? At the moment I can't bring myself to leave it connected if the charger is clicking in case whatever voltage/current cycling in the Ctek is going on could cause me problems. What do you think? Link to comment Share on other sites More sharing options...
Greenman Posted December 30, 2018 Report Share Posted December 30, 2018 Given the ctek provides a relatively low current I think it’s unlikely that it will actually damage anything. A number of people have commented that adding flying leads in this way is not necessarily the best as it does bypass the cars internal monitoring as as such the car doesn’t ‘know’ the correct charge state of the battery, Ive got to say I find this argument a bit suspect. How frequent is this clicking you hear, I imagine when in float/maintenance mode that the charger will be turning the current on and off via a relay and so some clicking would be normal. I have a 5.0mx that I use by connecting the crocodile clips when required(which in effect is the same as your flying leads method) but my car is outside so I would not have noticed any such clicking. Link to comment Share on other sites More sharing options...
M12MTR Posted December 30, 2018 Report Share Posted December 30, 2018 My Ctek MXS 5.0 doesn't click. I can 'sometimes' hear a slight hum. Link to comment Share on other sites More sharing options...
Greenman Posted December 30, 2018 Report Share Posted December 30, 2018 From the manual for your charger Quote Pulse Maintenance charge: The state of charge is between 95% and 100%. A pulse at 5 A is sent out if the voltage drops. This gives mini- mum water loss and maximum life. The charger could be connected for years without problems. The charger measures the voltage every 10 minutes to decide whether a new pulse should come. This means that these pulses can’t come more often than every 10 minutes. So if these clicks are every 10 minutes or so I would say normal. Link to comment Share on other sites More sharing options...
topradio Posted December 30, 2018 Report Share Posted December 30, 2018 Are you sure that the noise is coming from the charger. My 981 makes a funny clicking/buzzing from somewhere near the front every few minutes after I have unlocked the car. It makes the same noise if I lift the door handle while the car is locked. I have no Idea why it does it. Link to comment Share on other sites More sharing options...
Jon61 Posted December 30, 2018 Report Share Posted December 30, 2018 1 hour ago, Flyferrari said: I have fitted a flying lead directly to the positive terminal of the battery and an earth point on the top of the nearside suspension turret. 1 hour ago, Greenman said: A number of people have commented that adding flying leads in this way is not necessarily the best as it does bypass the cars internal monitoring as as such the car doesn’t ‘know’ the correct charge state of the battery, The description by the OP does sound like the correct way of making the connection - connecting the negative lead directly to the battery terminal would conversely be the way advised against by Porsche. The reason is the potential for damage to the battery sensor, rather than the battery sensor losing track of the state of the battery. See the page labelled as p142 (actually 150th page out of 186 in the pdf file) in the Boxster 981 'Technik Introduction' document, downloadable from Planet-9 at the following link (although free registration on that website is required first - it's worth it though, it's an interesting read on the 981's systems if you're that way inclined ) : https://www.planet-9.com/downloads.php?do=file&id=402 This states: "External charging/jump starting Every external charging/jump starting operation on the battery must be performed at the jump start terminal (positive battery terminal) and the corresponding ground terminal (on the wiper linkage). The negative battery terminal must not be used for external charging/jump starting since the battery sensor can be destroyed by voltage peaks during the charging operation/jump starting." I suspect though (but can't be sure) that an 'intelligent' charger like a CTEK would not cause the voltage peaks anyway that the text refers to, as Greenman also suggests above. I haven't experienced the clicking noise myself, but if your CTEK is doing its job as it seems to be, I probably wouldn't worry too much about it. I would have thought CTEK could have given a bit more guidance when you contacted them though - if you tried the CTEK on another car and it still clicked, should you be worried? Or should you be worried if it didn't click then? It sounds a bit to me as if some non-techie in Customer Services was just trying to sign off the call. Link to comment Share on other sites More sharing options...
RBD914 v2 Posted December 31, 2018 Report Share Posted December 31, 2018 No clicking on my Ctek charger but i charge via the socket in the glove box. Never had any problem via this method, why do you connect directly to the battery out of interest? Link to comment Share on other sites More sharing options...
Flyferrari Posted December 31, 2018 Author Report Share Posted December 31, 2018 12 hours ago, Greenman said: How frequent is this clicking you hear, I imagine when in float/maintenance mode that the charger will be turning the current on and off via a relay and so some clicking would be normal. The clicking is every few seconds. I suspect I wouldn't have noticed it if the time interval had been longer. 10 hours ago, Jon61 said: I haven't experienced the clicking noise myself, but if your CTEK is doing its job as it seems to be, I probably wouldn't worry too much about it. I would have thought CTEK could have given a bit more guidance when you contacted them though - if you tried the CTEK on another car and it still clicked, should you be worried? Or should you be worried if it didn't click then? It sounds a bit to me as if some non-techie in Customer Services was just trying to sign off the call. I'm afraid I tend to agree with your assesment of the reply I got from Ctek, hence my post here. My concern is that if the charging voltage is oscillating between say 0V and 15.1V that the battery might overcharge or even develop a "memory". I'll be honest, I have no idea if lead acid batteries suffer from memory in the same way as NiMh type batteries and I'm probably worrying over nothing. I just always take the view that something mechanical/electrical should work in a predictable/consitent way and if it isn't, then it's possibly doing harm. Not knowing how the Porsche's battery monitoring gubbins work also sets my brain running with the possible interactions. Thanks for the replies so far. If it carries on/nobody else has experienced the "issue", I might just replace the charger. It owes me nothing after 9 years and has saved several battery changes over that time (our MX-5 battery lasted over 8 years despite flattening it several times with the boot light and it being only slightly larger than a D cell!). It's just not worth my worry. Link to comment Share on other sites More sharing options...
Flyferrari Posted December 31, 2018 Author Report Share Posted December 31, 2018 10 minutes ago, RBD914 v2 said: No clicking on my Ctek charger but i charge via the socket in the glove box. Never had any problem via this method, why do you connect directly to the battery out of interest? Thanks for the reply. I connected directly to the battery for several reasons. Firstly, the Ctek gets a better "look" at the battery it's charging with less electronics in the way. Secondly, depending on the model and whether there is an "R" in the month, the internal charging sockets switch off after a period of time, halting the charging process. Lastly, and for me the most important, I don't like the idea of draping a lead across my interior trim/past various door seals on a regular basis. This was especially so when the car lived outside. I have no issue leaving the bonnet ajar with a charging lead running into the under-bonnet/battery compartment whilst stood outside. Leaving a window slightly ajar or pinning the cable with a door seal would bother me much more. Link to comment Share on other sites More sharing options...
EXY Posted December 31, 2018 Report Share Posted December 31, 2018 When the clicking is occurring have you held the charger and if so can you feel it physically clicking? I know one of my CTEK's clicked when I first connected and it actually felt like a relay was powering up. Link to comment Share on other sites More sharing options...
Flyferrari Posted December 31, 2018 Author Report Share Posted December 31, 2018 29 minutes ago, EXY said: When the clicking is occurring have you held the charger and if so can you feel it physically clicking? I know one of my CTEK's clicked when I first connected and it actually felt like a relay was powering up. I'll check next time I hook it up. It's definitely coming from the charger but I didn't grab hold of it......just switched it off! Link to comment Share on other sites More sharing options...
Jon61 Posted December 31, 2018 Report Share Posted December 31, 2018 2 hours ago, Flyferrari said: If it carries on/nobody else has experienced the "issue", I might just replace the charger. It owes me nothing after 9 years and has saved several battery changes over that time If your CTEK is that old, it probably won't have the setting specifically for Absorbent Glass Matt (AGM) batteries that you are likely to have on the 981. The newer CTEKs do have this, so are probably a better match to a more modern car anyway. 2 hours ago, Flyferrari said: Lastly, and for me the most important, I don't like the idea of draping a lead across my interior trim/past various door seals on a regular basis. This was especially so when the car lived outside. I have no issue leaving the bonnet ajar with a charging lead running into the under-bonnet/battery compartment whilst stood outside. Leaving a window slightly ajar or pinning the cable with a door seal would bother me much more. I also connect under the bonnet rather than inside the car, but bring the connector out from under the scuttle cover into the front compartment, then via one of the notches in the low barrier back up to the bottom of the windscreen. That way I can close the bonnet completely and lock the car, and connect/disconnect the CTEK plug & socket just near the back edge of the bonnet. If I'm not using the car for long in dry weather, I just tuck the 'car' end of the connector under the back edge of the bonnet out of sight which means I can get to it again to reconnect without even opening the bonnet. If I'm going out for longer or it's wet, I open the bonnet and tuck the end of the lead back into the compartment, being careful not to jam it between the bonnet and the battery cover when I reclose the bonnet. Link to comment Share on other sites More sharing options...
Greenman Posted December 31, 2018 Report Share Posted December 31, 2018 2 hours ago, Jon61 said: If your CTEK is that old, it probably won't have the setting specifically for Absorbent Glass Matt (AGM) batteries that you are likely to have on the 981. The newer CTEKs do have this, so are probably a better match to a more modern car anyway. As far as I can assertain the AGM setting charges at a slightly higher voltage (at least initially), it think this is just 0.2 or 0.3 V. This is the same approach that the cold weather setting on the older CTek chargers uses, so if your charger has a cold weather setting it should do the same, it you don’t use that the ctek will not harm the battery it might just charge to 90-95% though. 4 hours ago, Flyferrari said: . My concern is that if the charging voltage is oscillating between say 0V and 15.1V that the battery might overcharge or even develop a "memory". I'll be honest, I have no idea if lead acid batteries suffer from memory in the same way as NiMh type batteries The main concern with lead acid is deep discharges, they don’t like being run flat and especially left in a discharged state(although AGM are more robust in this regard, hence their use in start/stop applications) , they don’t have a memory in the same way as NiCad, in fact they like being constantly topped up. Unless there is a problem with the Ctek it should cause no overcharge issues, remember before smart alternators and electronics batteries were subject to a constant high ampage from the alternator. Having said all that I’m not sure why your charger would be clicking frequently in that way, I’m pretty sure my MXS5.0 doesn’t, but the 7000 is slightly higher powered so may use relays instead of transistors ? Link to comment Share on other sites More sharing options...
RBD914 v2 Posted December 31, 2018 Report Share Posted December 31, 2018 7 hours ago, Flyferrari said: Thanks for the reply. I connected directly to the battery for several reasons. Firstly, the Ctek gets a better "look" at the battery it's charging with less electronics in the way. Secondly, depending on the model and whether there is an "R" in the month, the internal charging sockets switch off after a period of time, halting the charging process. Lastly, and for me the most important, I don't like the idea of draping a lead across my interior trim/past various door seals on a regular basis. This was especially so when the car lived outside. I have no issue leaving the bonnet ajar with a charging lead running into the under-bonnet/battery compartment whilst stood outside. Leaving a window slightly ajar or pinning the cable with a door seal would bother me much more. Fair enough and a very interesting viewpoint. My own views are:- Charging via the glove box socket over the last 4 years never caused me a problem from the in-car electronics. The internal power socket has never switched off on my 981 whilst on charge. Regarding the charging lead going past a door seal, as it's a flexible rubber seal and the door can still be locked I doubt this is causing any issues to the seal or shrouded cable, in fact I prefer this to the idea leaving the front boot lid unlatched. Anyway, each to their own, just giving an alternative viewpoint for other readers! By the way, my car is garaged so I could use either method, I just went for convenience and it works fine. Link to comment Share on other sites More sharing options...
Dermot Posted December 31, 2018 Report Share Posted December 31, 2018 I currently have my 981 put way for a few months in the garage with a maintenance CTEK via crocodile clips directly on the + and – terminals on the battery. I guess I should stop that straight away and change the negative over to the wiper earth point. Could I have damaged the battery monitor module, if it gives up is there an error message ? Link to comment Share on other sites More sharing options...
Flyferrari Posted December 31, 2018 Author Report Share Posted December 31, 2018 50 minutes ago, Dermot said: I currently have my 981 put way for a few months in the garage with a maintenance CTEK via crocodile clips directly on the + and – terminals on the battery. I guess I should stop that straight away and change the negative over to the wiper earth point. Could I have damaged the battery monitor module, if it gives up is there an error message ? I very much doubt you’ll have done any damage. Not that it proves much but I’ve seen OPCs do much the same as you on their showroom cars! As with normal jump starting procedures, the biggest reason for the remote earth connection is to do with arcing which won’t be an issue on any Ctek. Link to comment Share on other sites More sharing options...
Flyferrari Posted February 14, 2019 Author Report Share Posted February 14, 2019 Hi Guys. I thought I'd update this thread so it might help someone else in the future. I eventually removed the trim that covers the battery and grabbed my multimeter. With the Ctek attached, powered, showing it's green light and clicking, the voltage across the battery terminals was 13.7V, spiking up to 14+V (I couldn't get an exact figure as my multimeter is quite basic) when the Ctek clicked and the going straight back down to 13.7V. Further investigation showed a resistance between the negative teminal on the battery and the Ctek connector of 8ohms. By comparison, the resistance between the positive terminal and the Ctek connector was 0.3 ohms. Now 8 Ohms really is bugger all but I thought I'd remove the bolt I had used to connect to the chassis (I used the spare bolt hole in the nearside turret) and see if I could improve things. I had assumed that, as the screw went straight into a metal hard point on the chassis, I wouldn't need to clean any paint off around the screw to make a good connection. Clearly I was wrong and you could clearly see some contamination/corrosion of the threads ( I used a stainless steel bolt). I have now carefully removed just enough paint around the hole so that the eyelet of the Ctek makes direct contact to the chassis but not so much as to leave bare metal showing once the bolt/washer/eyelet are back in place. I then smeared a light film of petroleum jelly over this connection to prevent any corrosion on the newly bared steel/further problems. The resistance on the Ctek negative connection now matches the positive at 0.3 Ohms. Whilst I clearly can't prove a negative but, after this light fettle, the Ctek has worked perfectly, without clicks, and the charging voltage in the multi-function display settles very quickly back to 13.9V rather than constantly saying 15.1V even on long drives. So if anyone has problems with their Ctek in future, as a first port of call I would check the resistance seen between the Ctek and the battery terminals. It doesn't seem to take much to muck it all up! The upside of all this for me is I've side-stepped the need to by a new Ctek! Kevin Link to comment Share on other sites More sharing options...
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