Battery getting flat.

[digisatman]

Hi all,

I have a w211 e270 Auto, that is getting flat at the weekend when I try to start it. I normally only drive at weekends, so looking to get a decent charger which can top up the battery every few weeks, with the battery still connected if possible.

Any recommendations?

thanks,

Digi

 

[wemorgan]

Here's a review of various chargers, but if your battery is not lasting 1 week then I suspect it is on its way out.

 

[digisatman]

Hi all,

There various models of the battery charger on following site:

http://www.theultimatefinish.co.uk/Store/Content/Default.aspx?PageId=3

Which one would be suitable for e270 w211?

This is my current battery:

017 Numax Car Battery 12V 88AH Premium Car Battery
Voltage - 12V
Capacity - 88Ah
CCA(SAE) - 750A

 

[Pug]

I'd seriously consider getting a new battery and/or getting the alternator tested.
There's no reason for it to go flat in that kind of space of time, really.

I use my 190E fairly infrequently and over winter (in Wales) I generally have the lights, wipers, blower, screen heater, stereo, amp and sat nav all running for the short trips I do make (~1 mile school run if it's raining) and when it's parked, I have a relatively large anti-theft LED blinking away on my Clarion, together with the clock.

 

[BlackC55]

Don't forget it is the battery under the bonnet not the one in the boot.

 

[NewMB]

I had similar problems with my W211 (seems to be common!), bought an MB Trickle Charger from dealer. Problem solved. Charges first to full capacity and then just "maintains" the power in the battery.

Great little thing actually and fits all MB cars.

 

[Flatflr]

I had a similar problem with my W202 as it was being left in airport car parks during the week due to travel with work. Ended up getting very sluggish when starting so decided to get a new battery fitted (only cost £75) but the old one did well considering it wasl the original 12 year old battery....

Nick

 

[smillion]

I have just had this cured by my dealer. New battery for the electrcial consumers (not the main big battery) and now everything is as it should be.

£170 mind you, but at least I have piece of mind that car will start.

Get it tested at the dealer.

Marc

 

[jeremytaylor]

Yes, I've just had mine replaced too. There's only one in the estates (in the boot). Mine was a 74 ah, so I upgraded it to a 100 ah.

 

[DieselE]

Hi all,

There various models of the battery charger on following site:

http://www.theultimatefinish.co.uk/Store/Content/Default.aspx?PageId=3

Which one would be suitable for e270 w211?

This is my current battery:

017 Numax Car Battery 12V 88AH Premium Car Battery
Voltage - 12V
Capacity - 88Ah
CCA(SAE) - 750A

In deciding which CTEK charger to go for you need to consider a couple of things.

Is you battery struggling to start the car or are you just getting the "Battery Protection" warning?

In your weekend only use, how far do you drive the car after starting it?

If the battery is struggling to start the car then you might want to consider the CTEK 7000 but if you are just getting the "Battery Protection" warning then the CTEK 3600 will meet your needs.

All pre-facelift W211s have two batteries be they saloon or estate. The second battery is installed in the engine bay beneath the air intake for the heating/air conditioning. The condition of both of them is monitored by the battery control module (the software relating to this was the subject of one of the early W211 recalls). The under bonnet unit is a 12AH back up battery.

When you start the car, it will take 10 miles or so of normal driving to put back into the battery the energy used. In winter, if you have the "welcome" lights enabled and because your car is a diesel the electric heater in the climate control will be running unless you have economy mode selected, it is very easy to run the battery down. You get the same problem every week because the battery never gets a chance to recover.

If you are in a position to leave your car on charge during the week then the smaller CTEK unit will be OK. It is designed to be left permanently connected but you do need to check that it has switched to maintenance mode after 24 hours or so.

 

[Ali_H]

This is my current battery:

017 Numax Car Battery 12V 88AH Premium Car Battery
Voltage - 12V
Capacity - 88Ah
CCA(SAE) - 750A

Are you sure that this battery is suitable for a 211 E class? Although I've never heard of this manufacturer I suspect that this is a conventional lead acid battery rather than the AGM type. Is it acceptable to replace one of the batteries with an ordinary lead acid type?