Flat battery - W204 C350

[merc07]

Couple of questions, the car has been used just 2 or 3 runs in the last couple of months as no work, I also trickle charged it about 4 weeks ago.
Went to start it yesterday to collect some essential eggs from a friend and it was dead.
Had to use my bike instead - last used in November and it started first turn - who says Italian electrics are dodgy..

Anyhow, while out, it charged up fine (4A charger), and now the charger says all ok.

Not that it probably makes a difference but there are a couple of options for battery type, AGM or Standard.
The difference is that AGM will charge to 14.8 vs Standard to 14.4 before reverting to the same maintenance charge of up to 13.2

Is my original main battery AGM or not ?
Also, I realise the smaller starter battery is charged while driving but does it also charge while using a battery charger on the main ? - I probably won't be using the car for a while yet..

 

[merc07]

Well, no answer so I measured it and NO, the auxiliary battery does not charge with a battery charger on the main.
You will have to charge the auxiliary independently if it needs it and the car is not being used.
As for AGM or not, it was cold out this morning so I used that mode anyhow. The boot is full so haven't looked at the main battery to find out...

 

[Chrishazle]

Battery type on my S204 C220 is not AGM or Gel, it's Wet (my charger has 3 options, I Googled for info and found it's Wet). However, I only have one battery rather than 2!

 

[Skd884]

Quite sure the w204 only has one battery?

 

[Atavus]

In the main, AGM is fitted on cars with stop/start.

 

[markjay]

The facelift W204 (2011-2014) was fitted with Stop/Start, hence AGM main battery, and a second auxiliary battery in the boot.

Pre-facelift W204 models (2007-2010) had only one main battery.

 

[merc07]

Other way around in mine, main is in the boot and auxiliary under the bonnet
Probably time for a new main soon as knocking on 8 years old..

 

[markjay]

Other way around in mine, main is in the boot and auxiliary under the bonnet
Probably time for a new main soon as knocking on 8 years old..

Is this the C350 CDI? Possibly with the larger V6 engines there's not room for the main battery in the engine bay.

 

[merc07]

Well spotted, yes the V6..

 

[MarcusRomer]

Quite sure the w204 only has one battery?

It has 2 one under airflow inlet in the engine compartment and other in the boot.

 

[merc07]

Ok, need to get one ordered, whats the best place to get one...anyone used Tayna, £180 for a Bosch S5 AGM 95 850.

S5 A13 Bosch AGM Car Battery 12V 95Ah Type 019 AGM S5A13

S5 A13 Bosch Car S5 Battery - AGM (Absorbent Glass Mat) Bosch Group are one of the leading battery manufacturer companies in the world and have been delivering quality German engineering in the automotive industry for more than 100 years! Bosch is a world renown company name that have and still...

www.tayna.co.uk

My original is the standard Merc fit Varta

 

[markjay]

Ok, need to get one ordered, whats the best place to get one...anyone used Tayna, £180 for a Bosch S5 AGM 95 850.

S5 A13 Bosch AGM Car Battery 12V 95Ah Type 019 AGM S5A13

S5 A13 Bosch Car S5 Battery - AGM (Absorbent Glass Mat) Bosch Group are one of the leading battery manufacturer companies in the world and have been delivering quality German engineering in the automotive industry for more than 100 years! Bosch is a world renown company name that have and still...

www.tayna.co.uk

My original is the standard Merc fit Varta

The original MB-branded Varta batteries are very good, check prices before deciding on non-original batteries, only downside is that (from memory) the MB-branded batteries carry a relatively short warranty of just 2 years.

Also, while both Bosch batteries and the Varta batteries are made by the same company, you can't buy the Varta model that MB sells under their own brand from another Bosch nor Varta - Varta only make this model for MB, the batteries they sell under their own name (or the Bosch name) are different models. I don't know if they are better or worse, all I am saying is that the Varta-branded batteries and the MB-branded batteries are differnt models so not directly comparable, in spite of both being made by the same manufacturer.

 

[Atavus]

Plenty of us here have used Tayna, they are fine.

 

[markjay]

Plenty of us here have used Tayna, they are fine.

As above. Also Yuasa and Exide are good brands.

 

[merc07]

Thanks for all the info, the Exide and Yuasa are a little cheaper.

I'll see what the local Merc dealer can do on the OEM in the morning and go from there.

 

[Tazzo]

I bought my battery from Tayna. Their online checker showed me the agm one however contacting them via email they provided me a wet version. Nonetheless I went ahead and bought the agm one. Probably overkill and overspent but hey ho.

 

[markjay]

AGM Battery is only required for cars equipped with Stop/Start technology, otherwise it's an upgrade to the standard battery.

 

[mbzclk]

Got the Bosch. It’s never let me down. I recommend that. Also get a lengthier warranty!

 

[merc07]

I gave up trying to get through to the Merc dealer - they were too busy...

Ordered the Bosch, thanks !

 

[markjay]

Got the Bosch. It’s never let me down. I recommend that. Also get a lengthier warranty!

Bosch battery standard warranty is 3 years, or you can pay a bit more and get a 5-year warranty. The batteries are the same, but they are colour-coded (blue/silver) to reflect the length of warranty.