CTEK MXS 5.0 battery charger

[K100RS]

I decided to purchase a CTEK MXS 5.0 battery charger for my motorbikes and my wife's Yeti. It charges up ok but makes a very noisy buzzing sound once connected to the battery which can be heard from my bedroom in the early hours of the morning as the garage is directly below the bedroom? Having tried the CTEK on three motorbike batteries ranging from 10Ah -30Ah and the Yeti 70 Ah I get the same noise generated. As the CTEK was making a horrible buzzing/ arcing sound from inside I returned the unit back to Amazon.

 

Another unit came very quickly from Amazon and plugged it in just like the original charger and no noise at first so I thought. Within one day the charger was quite when charging a flat battery and putting a few amps in but once it went onto trickle charge the buzzing racket has started up and continues just like the first unit?

 

Assuming it has a type of switch mode PSU on the pcb inside with a ferrite core soldered onto the board I am wandering if they all make this racket as I guess they don't pot the components on the board or there is a batch of rather loose fitting mini transformers in the unit vibrating that were manufactured in China.

 

Had checked the specific gravity of the cells with a hydrometer and volts with a Fluke DVM plus the current with another Fluke to monitor the charger was actually working ok.

 

Has anybody else had a CTEK MXS 5.0 that sizzles away on float or when charging?

 

 

FlyingBrick

[rustic]

I like interesting problems like this.

It might not be the ferrite cores, as these are normally fitted to reduce the high frequency interference from going into the mains.

However they are normally cemented in place as you say.

What will be in there is small pulse transformers, that operate at very high frequencies, these might have loose cores.

Now my first thought is, are you interfering with something else in the circuit.

For example, are you connected directly to a ring main 13 amp socket, and not an extension lead?

What else shares that power circuit? any electronic equipment, even on standby on that circuit?

There might be some resonance in the supply.

Sometimes at night, I hear my bedside light start buzzing, it has an energy saving bulb, and this is picking up interference from other devices in the house, or even next door.

Now if you live in an industrial area or areas where they use large motors, or welding machines, then this interference will get through to everything in your home. I have known flourescent lights buzz at the same speed as a grinding machine being used in a workshop 50 metres away.

I would be tempted to take the charger to another location, a friends house and try it.

Now... when items are manufactured to meet the CE regulations, I wonder how many of the essential modifications are actually fitted to production units, so that they all meet CE approval, and not just the one submitted for approval. Also some items are " cloned" and some companies don't see the need for the extra cost of thermal fuses or chokes to reduce emf emissions.

Look at the press, and you will see loads of electronic equipment recalls due to faults, from fakes some of which can cause fires.

Hope it helps,

best regards,

Richard

[gumdrop]

Can you try shielding it (I know you should not have to)

Could this be a problem C-tek should know about?

I have had no problem with my smaller models but they

are only used on my big 12v car and caravan batteries.

[DGW]

I have used one of these for a number of years and it is silent in operation.

[TR250man]

As above , silent.

[Gyp]

Ditto, mine's as quiet as a quiet thing on a quiet day in Quiet Town.

[K100RS]

Thanks Richard for the interesting information about chargers.

Had the house built from scratch and there is a direct cable to my sockets in the garage to the main MK switch box in the garage that I installed but where we live out in the country lanes with a step down transformer two houses away I can always read 245 volts AC with my RMS Fluke multimeter. My German made battery charger from Voltcraft runs ok plus my lab PSU with no problems.

Will try another place to charge the battery up.

 

The sound will obviously change if I grip the plastic case hard with my hands but don't want to break the seal underneath as they give a five year warranty with these CTEK's. Perhaps I need to build a small box with some insulation to keep it quite but then in the summer it might overheat? Had been thinking of sending this second one back but if they all come form the same company then the whole batch could have the same problem with Chinese components inside the unit.

Anybody else got a MXS 5.0 that buzzes loudly?

Sorry about the underline, can't get ride of it at the moment when typing this? Will try a friend who lives a mile away Richard.

 

FlyingBrick

•  

[175GDY]

No noise from my two CTEK XS 7000.

[nick74]

I have an MXS 5.0 and I've used it on a variety of different batteries located at different properties and it's virtually silent. If you hold it to your ear in a quiet room there is a very faint buzzing but that's it.

[rum4mo]

Thread revival, sorry but I didn't want to open a new thread on CTEK!

 

I bought a CTEK MXS 5.0 Test and Charge back in 2014 or 2015, and connected it up to my severely under used 2011 Audi S4, and trusted it, maybe checking the voltage while it was at various stages in the program "now and again".

All was good I think, until maybe 9 months ago, I went into the garage to use my wife's car, a 2015 VW Polo 1.2TSI, and I noticed that this charger, still connected to my car, was indicating a fault condition. I power cycled it and thought no more about it. A few weeks later I checked the charging voltage and it was 12.6V!  I power cycled it again and checked the charging voltage at each or most of the program stages, it was always 12.6V.  I tried lots of combinations of button pressing while power cycling to try to prompt it back into correct program charging voltage values - and failed, so I fitted my CTEK charger/support unit to it to get and keep that battery fully charged. I found another new MSX 5.0 charger on line and bought it and fitted it to this car and it worked okay.

Eventually by power cycling while holding down the mode button, the first MSX 5.0 Test and Charge reverted back to working as designed, and due to lockdown, started using this first one on my wife's Polo.

 

Prompted by people commenting on having a plug in 12V DVM I bought one and immediately got differing results when driving both cars, then discovered that the first CTEK MSX 5.0 is back to defaulting to a constant and safe 12.6V - which is a lot safer than it either flattening the battery or overcharging it I suppose, power cycling that one sorted it out again, then I checked the newer one connected to under used other car, it is charging at 12.7V, I power cycled it and it started charging okay, although when at its 14.7V section of charging program, it charges at 13.6V.

 

So my advice is to trusting CTEK charger users is, check the charging voltage maybe once a week to make sure that they are working as intended, I can't see me getting any redress from CTEK as I think I bought that second one from probably a not approved CTEK seller - and the first one is well out of its 5 years warranty.

Edited 10 April, 2021 by rum4mo

[xman]

13.6 may be due to it hitting current limit during the bulk/absorbtion phase, check again after a couple of hours and it should have risen if thats the case.

 

https://www.ctek.com/storage/28170E5A4DF8DDE255F2544A55F5C421179A3398C557729443D3E9C908F0382E/d4c71f1fcf354b37bdfb3841d00adafd/pdf/media/01d8e64db81c4259bda89213323dad93/MXS_5.0-manual-low-UK-EN.pdf