Unexplained Battery Power Loss!

[EddieHarrald]

Hi All. I have owned A 2003 E/class 320CDI for nearly two years, and in that time I have always had problems after the vehicle has stood for a couple of days, without use, in that the battery gets very drained and low, sometimes with not enough power to start it !
I have added a new Alternator, and both Mini, and Main Battery, being a 100 Amp One!
When this happens, the Dash Warning always comes up saying, “ Battery Protection System, Temporary Unavailable!”
Has any body experienced a similar problem that they can advise on the cause, and Remedy?
Many Thanks
Eddie Harrald
Ps. The Diesel consumption, economy is also very poor on this vehicle, and only returns approx, 20/21mpg locally, and 28/29 on a run! The computer only shows about 15 mpg on starting, and can drop to 8/10 in traffic!?

 

[AMGeed]

It sounds like you have the common w211 E class problem of a battery drain. I had it on and off with my E55 and it really needs proper diagnosis to find the cause. If you are competent enough you can get a multimeter and test all the fuses for a drain. Up to 65Ma is considered acceptable. It may be a door controller, seat controller, Comand not shutting down or a SAM fault to name a few.

Getting the car diagnosed by an MB independant with Star is the first step as it may well pinpoint the drain without further testing.
A Star test may also reveal the reason behind your high fuel consumption.

Where are you located just in case someone can recommend an MB indy nearby?

 

[EddieHarrald]

It sounds like you have the common w211 E class problem of a battery drain. I had it on and off with my E55 and it really needs proper diagnosis to find the cause. If you are competent enough you can get a multimeter and test all the fuses for a drain. Up to 65Ma is considered acceptable. It may be a door controller, seat controller, Comand not shutting down or a SAM fault to name a few.

Getting the car diagnosed by an MB independant with Star is the first step as it may well pinpoint the drain without further testing.
A Star test may also reveal the reason behind your high fuel consumption.

Where are you located just in case someone can recommend an MB indy nearby?

Hi Mr.Geed. Many thanks for your swift response! I am based in Camberley, Surrey! This is such a frustrating problem, that I would like to get sorted, and I have even thought of outing it in disappointment! Especially when I hear of other owners, getting 40 plus to the gallon !!

 

[AMGeed]

The closest recommended MB indy is Ian at Star Motors Caversham, about 20 miles away from you.
Give him a call and explain your problems. I'm sure he can sort your car out.

https://www.starmotorservices.co.uk/

.

 

[EddieHarrald]

The closest recommended MB indy is Ian at Star Motors Caversham, about 20 miles away from you.
Give him a call and explain your problems. I'm sure he can sort your car out.

https://www.starmotorservices.co.uk/

.

Many Thanks Mr. Geed !!

 

[grahamcol]

Just a thought on the fuel consumption. Does the temperature gauge get up to around 85 degrees or higher? My CLK 220 didn't when l first collected it and the diesel consumption was disappointing. I've since had the thermostat replaced and the consumption is much better. The heater works much better now too.

 

[EddieHarrald]

Just a thought on the fuel consumption. Does the temperature gauge get up to around 85 degrees or higher? My CLK 220 didn't when l first collected it and the diesel consumption was disappointing. I've since had the thermostat replaced and the consumption is much better. The heater works much better now too.

No faults in that way Thankyou !

 

[D5meister]

To check for which system is draining the battery in standby use a regular multimeter. Not an argos 5quid one. Borrow one that can see dc milli volts with ease. Put meter on mV DC and put the probes on the ends of each fuse - with the fuse in situ. There is a tiny slot in the plastic fuse body at each end to allow you to touch the top of the fuse 'blades'
If there is current flow thru that fuse you will see volts. The one with the highest volts is the one drawing the most current.
Take a look at its fuse number and read off the list of funtions to find what system it is.

 

[EddieHarrald]

To check for which system is draining the battery in standby use a regular multimeter. Not an argos 5quid one. Borrow one that can see dc milli volts with ease. Put meter on mV DC and put the probes on the ends of each fuse.
If there is current flow thru that fuse you will see volts. The one with the highest volts is the one drawing the most current.
Take a look at its fuse number and read off the list of funtions to find what system it is.

Many Thanks Matt. I will get your suggestion Tested!

 

[Flyinspanner]

A clamp meter is good for this.

You clamp a battery cable, switch off ignition and allow car to shut down.

You can read the drain on the meter.

Then pull fuses one at a time until you find the circuit with the drain.

Ones to look at which can cause issues

1. Do you have a tracker?
2. Keyless entry.
3. Comand.
4. Are glove box/boot lights going off when you close door (mobile phone camera in video mode is useful for this).

Good luck tracking it down.

 

[EddieHarrald]

A clamp meter is good for this.

You clamp a battery cable, switch off ignition and allow car to shut down.

You can read the drain on the meter.

Then pull fuses one at a time until you find the circuit with the drain.

Ones to look at which can cause issues

1. Do you have a tracker?
2. Keyless entry.
3. Comand.
4. Are glove box/boot lights going off when you close door (mobile phone camera in video mode is useful for this).

Good luck tracking it down.

Many Thanks !

 

[EddieHarrald]

Hi All. After having this annoying problem, as we are now on Lockdown, I have found the time to put my vehicle in to a garage to have the problem diagnosed, after testing with a Clampmeter they have found that my Problem, is That the Alternator is causing the drain!
This is Surprising, as having fitted a Reconditioned Unit, I didn’t give that a thought!
As I bought the unit over 12 months ago, it is now out of Warranty, and the firm that I purchased it from Schmidt’s, do not want to know!
Rather than having to purchase another unit, can anybody advise, if it is possible to rectify the Draining Fault, with my existing Unit?
Many Thanks
Eddie Harrald

 

[Blobcat]

Faulty diode in the rectifier pack can cause a drain, depending upon where the alternator stops. Had that on my 911, most days it was fine, others flat. New rectifier pack fixed it.

 

[EddieHarrald]

Faulty diode in the rectifier pack can cause a drain, depending upon where the alternator stops. Had that on my 911, most days it was fine, others flat. New rectifier pack fixed it.

Many Thanks For Your Swift Response! I will look into this !!

 

[EddieHarrald]

Hi All. My Problem has Been Diagnosed as An Alternator Fault, and the suggestion is to try a New Rectifier Pack !
£60 from Mercedes, or £25 on E/Bay! Is there any difference, and what does everyone recommend ??
Thanks Eddie

 

[D5meister]

Probably not that much. If u think the original failed, an ebay one cant be any worse.

 

[mioba]

Is the Alty on the car a genuine merc one. If so get a genuine merc rectifier. mercs dont like aftermarket electronics.
The Alternator on my w220 (2004) failed last year so thier life span seems to be about 16 years.
I replaced the entire unit for a genuine, do it once do it right, hope it last another 16 years.

Alty faults are easy to diagnose with a multimeter, hope the garage got the problem!

What I dont undertsand is that if you had this problem since you purchased the car, did the last alternator change not solve the problem....

 

[EddieHarrald]

Is the Alty on the car a genuine merc one. If so get a genuine merc rectifier. mercs dont like aftermarket electronics.
The Alternator on my w220 (2004) failed last year so thier life span seems to be about 16 years.
I replaced the entire unit for a genuine, do it once do it right, hope it last another 16 years.

Alty faults are easy to diagnose with a multimeter, hope the garage got the problem!

What I dont undertsand is that if you had this problem since you purchased the car, did the last alternator change not solve the problem....

Hi. Thanks for the reply! The alternator change originally cured the problem, but unfortunately I used a Refurbed unit, of which has only lasted two years! I have now fitted a Genuine Mercedes Rectifier Pack, and, Fingers Crossed, Seems to have Cured The Problem !!

 

[EddieHarrald]

Hello All. Unbelievably, I am still Lumbered with My Drain Problem!
The car is in a garage, and after returning it to them, as still Draining, and not right, they have fitted a New Mercedes Rectifier Pack, which has reduced the drain, but it is still Draining, Below the acceptable limit. They have pulled all the fuses, and it is still Draining ! Anybody got Suggestions to Cure This Nightmare !!

 

[mersum1es]

How much the drain current is?

One not fused place is breather heater, should be rather easy place to unplug and test.

I recently read memory seats would have two voltage feeds, where another one is not fused, so unplugging seat fuse wouldn't isolate the draw if another circuit is faulty. I have not yest verified if that's true.

Electric heater boosted in air duct draws huge amount of current if short circuited and is easily seen in current reading.

Have you got yor aux battery isolation relay checked? If aux battery is again bad and relay jammed, it will draw main battery.

How much your alternator is charging. W211 have couple of different specific regulator packages, and wrong type is not communicating with car (though it should not cause draining and limp mode charge is 14,3V constantly).

No aftermarket radio, or alarm fitted? No dash camera?