START STOP

[markjay]

Getting a code reader is a must for any Mercedes owner... though it's worth noting that a failed main battery (one of the most common reasons for Stop/Start not working) does not usually flag-up a fault code.

The scanner will be helpful if the Stop/Start is failing due to other issues that do flag-up a fault code.

 

[HomeJJames]

If money is tight Aldi do a very good smart charger, maybe not as good as the Ctec but I use mine on my car and bike, it works really well.

Thanks for the tip ! Lots of smart and help people on here

 

[BTB 500]

I don't usually have the air con on, in fact, I rarely have it on as I don't like to use fuel if I don't need to (sooner open the windows or open the roof!).

Pretty sure this only applies at low speeds. Otherwise the increased drag from a window or roof being open affects the mpg more than having the aircon on (for modern cars).

 

[geoffus]

Pretty sure this only applies at low speeds. Otherwise the increased drag from a window or roof being open affects the mpg more than having the aircon on (for modern cars).

I' m amazed people still think the aircon cost them so much money they refuse to turn it on.

 

[tonysmb]

I would have thought the stop start not working was a bonus . Does it turn off completely if you press the switch?

As has been mentioned, there are many criteria that might affect its operation; if it was me I'd just buy a trickle-charger and try that for a few weeks, making sure it's set for AGM batteries and save the MB diagnostic fee.

 

[geoffus]

I would have thought the stop start not working was a bonus . Does it turn off completely if you press the switch?

As has been mentioned, there are many criteria that might affect its operation; if it was me I'd just buy a trickle-charger and try that for a few weeks, making sure it's set for AGM batteries and save the MB diagnostic fee.

I agree, this time of year a trickle charger is your best friend.

 

[mikrt]

Getting a code reader is a must for any Mercedes owner... though it's worth noting that a failed main battery (one of the most common reasons for Stop/Start not working) does not usually flag-up a fault code.

The scanner will be helpful if the Stop/Start is failing due to other issues that do flag-up a fault code.

@markjay, it won't flag up as a fault code, but as a parameter not met

photo is of mine from last year

with some others showing a few others

 

[DITTRICH]

When my c200se charges, I see the charging bar appear next to the mpg on the relevant screen. The car will not go into glide mode when charging takes place. If the battery is dodgy and requires frequent charging, it ought to show up on this screen. The start stop is better off. The first thing I do after switching on is select the eco mode and then press the off button (rear button, left hand side, from the twiddly centre dial where the auto gear selector is no longer. Coasting down hills at 50mph+ and 700rpm in D is very beneficial for fuel consumption. As I said, I think you need to keep your eye on the charging graphic to see how and when it charges. That's what I'd do first before phoning the dealer.

 

[leef44]

Thanks for the info and will be sure to check that any charger will have this option. I don't usually have the air con on, in fact, I rarely have it on as I don't like to use fuel if I don't need to (sooner open the windows or open the roof!).
I'm confident that the s/s failing to turn on/off is not a fault but perhaps just a top up to the battery is all that is required. MB is going to sting me of £110 to find out but either way, hopefully I should get the solution from that. Cheers

For peace of mind, I would just go with the C-Tek as recommended by another poster. The Mercedes branded one is actually a C-Tek and many MB owners use this, it works for AGM batteries. You can find cheaper alternatives but it's only a one-off purchase.

 

[Bayleaf]

I' m amazed people still think the aircon cost them so much money they refuse to turn it on.

Even in the winter months it pays to run the AC for a few minutes once a week if the car's not being used much to circulate the system and stop the internal seals from drying out.
It's all so a great demister.

 

[HomeJJames]

You connect it to the charging post under the bonnet, and then plug it into the mains. The good ones are intelligent and will charge and condition your battery whilst it’s on the car.

The CTEK MXS 5.0 is very well regarded, and I’m delighted with mine. Shop around but Amazon are both good value and quick to deliver (currently £69.99) at the momen

https://www.amazon.co.uk/CTEK-MXS-5-0-Reconditions-Motorcycle/dp/B00FC42HAA

I am going to purchase a trickle charger and the one recommended seems a good bet. Do I need to link it up to the main battery or to the auxiliary battery ?

 

[Bobby Dazzler]

I am going to purchase a trickle charger and the one recommended seems a good bet. Do I need to link it up to the main battery or to the auxiliary battery ?

Just use the charging posts under the bonnet

Have you been to the main dealer?

 

[wongl]

I am going to purchase a trickle charger and the one recommended seems a good bet. Do I need to link it up to the main battery or to the auxiliary battery ?

I think there is a capacitor in your car acting as the Aux Battery. In this case, there is no need to hook up the charger to the capacitor. On the other hand, if there is physically an Aux Battery in your car, you will need to hook up charging leads to the Aux Battery too since this is normally isolated from the main Battery.

 

[Bobby Dazzler]

I think there is a capacitor in your car acting as the Aux Battery. In this case, there is no need to hook up the charger to the capacitor. On the other hand, if there is physically an Aux Battery in your car, you will need to hook up charging leads to the Aux Battery too since this is normally isolated from the main Battery.

I believe that connecting to the charging point - rather than directly to either battery - will charge both batteries safely.

 

[merc07]

I believe that connecting to the charging point - rather than directly to either battery - will charge both batteries safely.

I know this does not work on the W204 350 - only way to charge the aux is connect directly to it..

 

[wongl]

I know this does not work on the W204 350 - only way to charge the aux is connect directly to it..

The charging point/jump start point in the engine does not charge the Aux Battery in the R172 either. I have resorted to fitting a CTEK quick connect to the main battery in the engine bay and also a second pair to the Aux Battery located behind the passenger seat.

On my 205 C300h, I simply hooked the CTEK quick connector to the main battery located in the boot. As I only used the C300h for a total of 82 miles in 2020, the CTEK charger is a must-have!

 

[HomeJJames]

Just use the charging posts under the bonnet

Have you been to the main dealer?

No, not yet, its booked in next week for a £110 check (ie, just a diagnostic check). I've been quoted for a new battery from Halfords, is a 115AGM 80AH, if they fit it, do I need codes any codes for resetting the radio or other things ? It seems a like for like with the existing battery and £100 cheaper so this may cure the issue - do you agree ?

 

[Gazwould]

How much is this Halfords ( Yuasa ) battery ?

 

[Bobby Dazzler]

No, not yet, its booked in next week for a £110 check (ie, just a diagnostic check). I've been quoted for a new battery from Halfords, is a 115AGM 80AH, if they fit it, do I need codes any codes for resetting the radio or other things ? It seems a like for like with the existing battery and £100 cheaper so this may cure the issue - do you agree ?

Personally I wouldn't change the battery or pay for diagnostics until I had reconditioned (posh word for recharged) the battery. Batteries do get stretched at this time of year - especially in the current climate - and just because a battery is low, it needn't be replaced. The main dealer will probably diagnose low voltage and replace the battery without checking whether it's healthy.

So I would recondition/recharge it first. If that fixes it then I would wait and see if fault returns, and in what timeframe, and if it returns quickly then I would replace the battery. Personally I wouldn't pay for diagnostics until the final step, because it's highly likely to be the battery, and then it's likely that recharging it will kick your stop-start back into life.

I'm not far away, and so as I mentioned before I'm happy to arrange for someone to bring you one of my CTEK MX5.0 conditioners.

 

[Deleted member 65149]

You connect it to the charging post under the bonnet, and then plug it into the mains. The good ones are intelligent and will charge and condition your battery whilst it’s on the car.

The CTEK MXS 5.0 is very well regarded, and I’m delighted with mine. Shop around but Amazon are both good value and quick to deliver (currently £69.99) at the momen

https://www.amazon.co.uk/CTEK-MXS-5-0-Reconditions-Motorcycle/dp/B00FC42HAA

I've just received my CTEK MXS 5.0 from Amazon. It's charging my car battery right now. The instructions are a bit vague - I couldn't decide whether to set it to "normal battery programme" (for use with a wide range of batteries, including "many AGM batteries") or the "AGM option" (for "charging most AGM batteries"). I've assumed I have an AGM battery because I have start/stop and it's too bloomin cold to stand outside fiddling with taking the battery cover off to have a look. I've set the charger to AGM mode and all appears ok for now.

BTW, I haven't noticed whether or not the start/stop is working lately. All my journeys in the last couple of months have been too short to expect it.