CTEK MX 5.0 questions / 2019 C63

[rs67]

I'm having problems with a partially charged starter and had a critical warning the other day. I may need to get the battery replaced under warranty. In the meantime, I plan to get a charger. The CTEK MX 5.0 seems to be the one that people recommend, and I don't particularly wish to fork out almost 3x as much for the MB OEM one, which I believe is a rebranded CTEK anyway.

Looking at the CTEK MX 5.0 user guide, the first cycle is a desulfate one, which uses 15.8v. The MB manual has dire warnings not to exceed 14.7v charging voltage.

So using this charger would violate the express warning in the manual not to exceed 14.7v.

Is there a better charger to use, one that does not go above a 14.7v charging voltage?

 

[whitenemesis]

If MB sell the CTEK with their own label on it (and they do...) surely it must be ok to use with their cars?

 

[rs67]

If MB sell the CTEK with their own label on it (and they do...) surely it must be ok to use with their cars?

The one MB sells does not look like the MX 5.0. It might possibly be the CT5 Start/Stop. Looking at the specs of the CT5 start/stop, it has a max charging voltage of 14.55v and 3.8A. It does not have the harmful desulphate cycle, so may be the one to go for instead.

 

[rs67]

Just found this, so the CT5 start/stop looks like it will be a good choice in my case

 

[Deleted member 126251]

I'm having problems with a partially charged starter and had a critical warning the other day. I may need to get the battery replaced under warranty. In the meantime, I plan to get a charger. The CTEK MX 5.0 seems to be the one that people recommend, and I don't particularly wish to fork out almost 3x as much for the MB OEM one, which I believe is a rebranded CTEK anyway.

Looking at the CTEK MX 5.0 user guide, the first cycle is a desulfate one, which uses 15.8v. The MB manual has dire warnings not to exceed 14.7v charging voltage.

So using this charger would violate the express warning in the manual not to exceed 14.7v.

Is there a better charger to use, one that does not go above a 14.7v charging voltage?

Make sure you know what type of battery you have (AGM or flooded lead acid) and use the correct programme. Mine (MX7) has a separate program for AGM.

 

[rs67]

Make sure you know what type of battery you have (AGM or flooded lead acid) and use the correct programme. Mine (MX7) has a separate program for AGM.

It's an AGM battery. 2019 facelift C205 C63

Unfortunately ALL programs on the MX 5.0 (and probably the MX 7.0 too) have the harmful desuplhate cycle.

 

[flowrider]

The first 3 cycles take seconds to complete so I doubt there will be any issues.

 

[AMGeed]

The first 3 cycles take seconds to complete so I doubt there will be any issues.

It's a valid point for me as well as I have an AGM start/stop battery in my E63. I recently gave the main battery (also AGM) a boost with the Ctek MX-5 for the first time last week, but was thinking of putting it on the stop/start battery if and when needed. Maybe I should re think?

 

[Atavus]

I use my CTEK on AGM batteries and have not experienced problems. I wouldn’t worry about it.

 

[AMGeed]

I use my CTEK on AGM batteries and have not experienced problems. I wouldn’t worry about it.

Have you connnected the charger directly to the stop/start battery or just the main battery?

 

[KennyN]

How much is the genuine MB (ctek) charger , I recently purchased a genuine BMW (ctek) item from the dealers and it was only £64. I figured that if the car needed a new battery under warranty there would no get out clause as it was a BMW accessory ,even though it does still say ctek on the back of the charger.

K

 

[flowrider]

Have you connnected the charger directly to the stop/start battery or just the main battery?

What's special about the stop/start battery?

 

[AMGeed]

What's special about the stop/start battery?

It's a small battery and I don't know if its recommended to push 5amps through it and charge it up to 15.8v, even for a few seconds.
Thats why I'm asking

 

[Atavus]

I’ve never connected a charger to an AGM battery, because it’s not recommended. They usually have a BCM, so you connect elsewhere.

 

[Deleted member 126251]

It's an AGM battery. 2019 facelift C205 C63

Unfortunately ALL programs on the MX 5.0 (and probably the MX 7.0 too) have the harmful desuplhate cycle.

View attachment 91880

MXS7 does not (14.7 max) - I've just rechecked my user guide. I also emailed (Ctek) a few years ago and they confirmed that my charger is fine on AGM however, I'm going to check with them again. I wonder if the 15.8V in the pic you posted is not a typo?

 

[flowrider]

My R230 SL has an AGM battery which I have been charging with my Ctek for the last 3.5 years. I connect directly to the battery and have never had any issues. I just make sure the AGM mode is selected on the charger. At first I was using an MXS 5.0 but I now use a MXS 10.

 

[Deleted member 126251]

I use my CTEK on AGM batteries and have not experienced problems. I wouldn’t worry about it.

Ditto - I've had my MXS 7 for about 10 years and used it for AGM in various (Including 4 MB) vehicles and caravans (offroad - battery arrays with inverter for bush camping). No issues.

 

[flowrider]

From the MXS 10 product sheet.......

"The special AGM mode is ideal for AGM battery chemistry and where Start/Stop batteries are to be charged or maintained"

 

[rs67]

I wonder if the 15.8V in the pic you posted is not a typo?

I very much doubt it. I copied it directly from the user manual for the MX 5.0 and they also refer to it on a youtube instructional video. The link I posted above also talks about this issue

 

[Deleted member 126251]

I very much doubt it. I copied it directly from the user manual for the MX 5.0 and they also refer to it on a youtube instructional video. The link I posted above also talks about this issue

Yes - the implied typo is possibly by CEK not you.