15 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCTEK MXS 5.0 error
Leading reported evidence
Disconnect batteries where it seems
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
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Performed · outcome unconfirmed
I only occasionally use it now and only on disconnected batteries where it seems to be ok.
Leading evidence: 'Disconnect batteries where it seems' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'battery starting' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check date last' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
Now…..I’d be thinking the battery needs changing (will check date last changed) but 3 things to consider:
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Performed · outcome unconfirmed · Original poster
Used the same unit on previous Caymans and did buzz a little but seemed fine in use.
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Performed · outcome unconfirmed
I've got an old ctek (without all the lights) which I've used for years on all different vehicles with no problems, then I got a mxs 5.0 and that doesn't like my Porsche, or my motorbikes.
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Suspected cause
It had done this a few times on my previous Macan and I assumed it was the battery starting to deteriorate as per CTEK manual.
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15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 1 discussions
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Generation: 20261026T161109Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I have my 996 on a Ctek mxs 5.0. It’s been sat on the float charge since last use about 4 weeks ago. Went in the garage this morning…..red error light on at phase 5, which indicates battery not holding charge.
Now…..I’d be thinking the battery needs changing (will check date last changed) but 3 things to consider:
1. The charger was on float for c 4 weeks - is that normal behaviour for a battery to error like that?
2. I moved the charger - all the lights went out - seems the connection may be loose on the wire coming out of the unit to the battery - if I move that wire it does the same again
3. Slight buzzing from the unit
Used the same unit on previous Caymans and did buzz a little but seemed fine in use. VX220 is on a ctek that is silent and not seen any error lights.
Thoughts - change the ctek? Change the battery? If I change the ctek mxs 5.0, mxs 3.8 or the newer models such as “time to go” . Thank you
I've had the same problem recently. Happened a couple of times over the year, the CTEK seems to drop out and then the battery stuggles. I changed the battery in Aug (under warranty), and the same has happened.
After reading a few posts online, seems that it has happened to a fair few, but only with 996's. I've just bought a Noco Genius 5, probably too early to give feedback yet, but seems stable with a new battery.
I've got an old ctek (without all the lights) which I've used for years on all different vehicles with no problems, then I got a mxs 5.0 and that doesn't like my Porsche, or my motorbikes. On the motorbikes it gets the red light after a week or so everytime. I only occasionally use it now and only on disconnected batteries where it seems to be ok.
I've now bought a Noco Genius 5 and that's perfect on everything including my campervan which has nearly 3 x the battery capacity recommended by Noco!
Saying all that, it does seem like you have a faulty connection which could be all it is!
I had the same ... first on my Merc which has two batteries, and then on my 997.2. I've not got to the bottom of it yet but my mechanic is testing my CTek MX5.
I've no confidence in CTEK chargers after my episode with the McLaren branded one. It would show a full state of charge only to find it hadn't added anything to the battery
Given McLaren have a lithium battery I decided like a fool to buy the CTEK Lithium model to give it a go and that would on occasion go through the cycle then either fault or not go to the final stages to the green light which gave me no confidence in it when a McLaren battery is c£2k and the associated error issues. A lot of McLaren owners who had issues went to NOCO.
The suggestion you had to either have the CTEK on a timer to switch off and on once a week or press the reset button every so often was not my idea of how they work. Granted for 993 owners I can see the appeal given they'll be in the garage over winter looking adoringly through the plastic of the carcoon and perhaps entertaining themselves by inflating and deflating the spare wheel marvelling at the increase in size to pass the time until clear skies and warm weather to put the car back on the road in June.
The consensus seemed to be they don't have a very long life and for what is supposed to be a premium product my Halfords 20yr old block plug style trickle charger is still performing well and had proved itself to keep a car battery topped over for over 6months. For a lead acid battery I'd rather buy a Wong's Chinese £20 trickle charger than stump over a ton of the folding for a CTEK
I had the same issue on one of my CTEK mxs5.0 that was connected to my 991, seems the sligtest movement triggered phase 5.
It had done this a few times on my previous Macan and I assumed it was the battery starting to deteriorate as per CTEK manual.
However I plugged it in to my brand new BGTS4.0 and it did the same thing.
As it was over 5 years old I bought a new one and it has stayed on phase 8 with no issue, so I would say it's your CTEK.
And thanks for all the input and thoughts. Are Noco a "worthy" replacement or is a new ctek the best way to go... Warranty etc for 5 years, this one being 7 years old??
I can't comment on Noco but I've had Ctek for a long, long time on both my 911's and Range Rovers. I've had no issues at all and if you've ever owned a Range Rover, you will know how important battery voltage is!
Personally I would go CTEK, I have found them very reliable until this. Like yours, my device which started playing up was around 7 years old and outside of the 5 year warranty.
They have send me things like new connector o rings which had deteriorated so good customer service.
I’ve had no problems with my MXS5.0 on the 996, and the lead gets brushed about a lot. I do have the unit itself fixed to the garage wall and use the long extension lead across the floor and up into the car.
You pays your money and makes your choice but for me the 'prestige' associated with Ctek is folly. It's akin to driving an Aston Martin and finding out if you peel the badge off the key fob it's got a Volvo one underneath. Whether under the label of the Ctek it has Wong Industries Shenzhen China, I can't comment.
