Why Battery Discharges

[Choclate]

Hi

I have got a MB E270 CDI, that I bought recently. This is my first experience of MB and Diesel cars as well. I am surprised that the battery is discharged when I left the car parked for a week or so. :-(

I had Petrol cars in my life before and never had this problem before. Is that typical problem of this model or my car battery is any issue. But to me it looks like car has got the new Battery.

Also what is the reason, and solution to the problem ? Thanks for the early attention.

 

[Alex M Grieve]

Hi

I have got a MB E270 CDI, that I bought recently. This is my first experience of MB and Diesel cars as well. I am surprised that the battery is discharged when I left the car parked for a week or so. :-(

I had Petrol cars in my life before and never had this problem before. Is that typical problem of this model or my car battery is any issue. But to me it looks like car has got the new Battery.

Also what is the reason, and solution to the problem ? Thanks for the early attention.

Hello Choclate and welcome to the forum.

This problem is not typical of MB or of diesel cars - you have made a good choice on both counts. Greater brains than mine will help pinpoint the problem and solve it.

They may be taking morning coffee at present, but I am sure one will be along soon! :wink:

 

[Cole@MBS]

On the post of the battery will be a date stamp, that will tell you how old it is!

You need to have a drain test done to find what is draining it. It could be any number of control modules on that model!

Welcome to the forums!

 

[Choclate]

Thanks Guys, Its a good and quick reply. But how can I do the drain test ?

 

[jberks]

Its a quite common problem but its not normal. As S-A-M / U-N-I-T has said, it's a fault somewhere. The battery could be past its best or else there are a number of modules and components that can cause this. The basic problem is that unlike old cars where turning off the key cut the power, 211s are heavily computerised and modules are expected to turn themselves off when they're ready. Unfortunately sometimes they don't. You need to get it tested and then once a drain is identified it's a simple process of pulling fuses to identify what is doing it. On our 220 it turned out to be the switch panel in the dashboard of all things, but seat controllers, command units etc are more common culprits.

 

[Choclate]

Malfunction

Sometimes on the dashboard, I am getting this message; I don't remember the exact message phrase but something like this.

Malfunction 1 ; One of the electrical consumers are not switched off or on

Do you think it could be the reason, Also how could that be identified ?

 

[Dec]

If the battery was in poor condition when you parked the car then it being flat after a week is to be expected.
Get yourself something like this… http://www.fixthisride.com/showproductdetail.jsp?prod_id=154452 … it will tell you approximately the condition of your battery before you start the car, it will also tell you the running voltage while you are driving.

The can be got for around £10, very useful, you have instruments to tell you coolant temperature, fuel level, engine speed, road speed, even the time of day but nothing to indicate the condition of the battery.

Dec

 

[jberks]

Sometimes on the dashboard, I am getting this message; I don't remember the exact message phrase but something like this.

Malfunction 1 ; One of the electrical consumers are not switched off or on

Do you think it could be the reason, Also how could that be identified ?

This warning comes up when the voltage is low. Its telling you its switched off non essential components to save power. Normally by the time it has come up, the power is back and everything is working again. Bottom line, the battery is down, it's why thats the problem.

The only way is to put a meter in line with the battery and monitor current draw when everything is off. If excessive then pull fuses until it drops off. Its a tricky task, made harder by the fact that some things don't switch off immediately and in the case of ours, the problem wasn't there for the first 20 mins. Only after then did the component wake up and start draining the battery.

 

[jberks]

If the battery was in poor condition when you parked the car then it being flat after a week is to be expected.
Get yourself something like this… http://www.fixthisride.com/showproductdetail.jsp?prod_id=154452 … it will tell you approximately the condition of your battery before you start the car, it will also tell you the running voltage while you are driving.

The can be got for around £10, very useful, you have instruments to tell you coolant temperature, fuel level, engine speed, road speed, even the time of day but nothing to indicate the condition of the battery.

Dec

Looks a good product but then the car does monitor voltage and charging and will warn you if either drop below the correct levels so how much use it is on a merc I'm not sure. Great for older vehicles though.

 

[television]

211 cars up to 2005 had 2 batteries, the warning consumers switched off can come up if the car is not used very much, or if the car in not shutting down the wake up circuit.
Many things could do this from the OHC panel to a seat memory module.

The best way to go about it is to charge both batteries, then let the car go to sleep, around 25 mins, do not open any door or it will wake up again and you will have to wait until it goes to sleep again. A clamp meter is the easiest way to measure the current, the max allowed on the 211 is around 55-60 ma max

 

[Choclate]

Jump-start

Can I try it JUMP-START by other car?
What should I consider to do this ?
I have a Renault Clio with Battery of 12v, will it do?

 

[television]

On re reading your first post every thing could be normal. these cars will not go more than 2 weeks.

You would be much better off buying a small charger, as you could then top the batteries up say once a month, I have to do that on my SL

 

[Cole@MBS]

On re reading your first post every thing could be normal. these cars will not go more than 2 weeks.

You would be much better off buying a small charger, as you could then top the batteries up say once a month, I have to do that on my SL

Book time is about 6-8 weeks for a 211 to have enought left to start (on paper), in the real world its about 4-6 weeks, something is draining it!

 

[AndrewIles]

I've got a Porsche 911 and if that is left standing for 2 weeks the battery would be as flat as a pancake. The car's security system will be draining power all that time.

I agree with Malcolm and purchasing a trickle charger/battery charger would be a wise investment.

I use a CTEK model that has interchangeable connectors that plugs directly into the cigarette lighter socket or onto the battery itself.

 

[television]

At a 50ma sleeping current drain, that would 33.6 amps gone in 4 weeks, once the top has been creamed off of the battery then the next rate of discharge becomes higher as nothing can re set

 

[sailorjim]

I'm surprised that some members report flat batteries after 2 weeks. My old W203
(2002) has for the last few years been left outside over the coldest part of the winter for up to five weeks and fires up as if it had just been parked that day. It must be a malfunctions, as suggested, but finding it can be a problem. Chum of min e had this with an old E class a few years ago and MB never found the cause. His solution was to keep a solar battery charger permanently in the car and this provided enough to keep him going. Beware - there is a lot of rubbish for sale out there.

 

[television]

I'm surprised that some members report flat batteries after 2 weeks. My old W203
(2002) has for the last few years been left outside over the coldest part of the winter for up to five weeks and fires up as if it had just been parked that day. It must be a malfunctions, as suggested, but finding it can be a problem. Chum of min e had this with an old E class a few years ago and MB never found the cause. His solution was to keep a solar battery charger permanently in the car and this provided enough to keep him going. Beware - there is a lot of rubbish for sale out there.

The more sophisticated the car the more involved the wake up circuit . We are getting to the point of it being a night mare situation in tracking down some of these things once they start leaking