Battery Protection warning - 2005 CLS

[village idiot]

I have had the car now for about 2 weeks and everything is fine. The car has seen plenty of use, but yesterday morning i received a warning for battery protection (convenience functions temporarily unavailable).

After 10 minutes the warning disappeared but was back again this morning.

I know that this often points towards a tired battery, but the supplying dealer made mention of replacing the battery as part of the pre-sale prep. I can only assume that this was because he was getting the same warning.

To me, this points possibly towards a more deep-seated issue. Could it be a relay or something like that?

The car is going in to Pentangle next week for the top idler pulley to be replaced and the auto box to be serviced, so i might ask them to have a look, but a little advanced knowledge would be good.

thanks

 

[whitenemesis]

I get this all the time despite replacing both batteries. The message normally clears before I've left the driveway, never longer than 2-3mins.

The car has been checked over numerous times with no error codes stored. The BCM software has been updated as per MB's recommendation.

Even if I put the car on trickle charge for a couple of days the message comes back.

My BiL, who ran the service dept in a MB dealership for a couple of years said this was the most common complaint for the E and CLS of that age, especially the 500 and 55k.

If the charging system checks out as healthy one just lives with it...

Have the Aux battery in the engine bay checked out, this often gets forgotten about

 

[b1g1an]

I get this all the time despite replacing both batteries. The message normally clears before I've left the driveway, never longer than 2-3mins.

The car has been checked over numerous times with no error codes stored. The BCM software has been updated as per MB's recommendation.

Even if I put the car on trickle charge for a couple of days the message comes back.

My BiL, who ran the service dept in a MB dealership for a couple of years said this was the most common complaint for the E and CLS of that age, especially the 500 and 55k.

If the charging system checks out as healthy one just lives with it...

Have the Aux battery in the engine bay checked out, this often gets forgotten about

If you get low power on the front battery you definitely know about it as the dashboard lights up red and you have one of those oh ******** there goes the SBC pump moments.

I know you've got a CTEK charger but if you have one with the renovation function give that a go. I had similar on mine, trickle not working for long in cold weather, but after running that it'll happily sit for three weeks before it reappears. They recommend once a year so I do it just when the cold weather comes on.

 

[grober]

I would question whether the main battery was in fact replaced- sometimes they have a manufacture date code on them.

http://www.pistonheads.com/gassing/topic.asp?t=1289389
On recent varta--- 4 nos on top of the negative terminal first two= week of manufacture second two= year. example week23 /2012

 

[AMGeed]

I get this all the time despite replacing both batteries. The message normally clears before I've left the driveway, never longer than 2-3mins.

The car has been checked over numerous times with no error codes stored. The BCM software has been updated as per MB's recommendation.

Even if I put the car on trickle charge for a couple of days the message comes back.

My BiL, who ran the service dept in a MB dealership for a couple of years said this was the most common complaint for the E and CLS of that age, especially the 500 and 55k.

If the charging system checks out as healthy one just lives with it...

Have the Aux battery in the engine bay checked out, this often gets forgotten about

I have exactly the same experience with my E55. New consumer and aux batteries a year ago and occasionally get the convenience warning if the car is unused for a few days.
I had all the fuses and relays checked for a drain, and thought I'd cured things when replacing a known faulty door control module. But I still get the message occasionally.

 

[Dogbreath]

If they have changed the battery then there must be something draining it... My E55 was doing exactly the same....got the message then after 5-10 mins all back to normal.
Changed both battery's with MB ones and not had any messages since fitting a month ago. And the car is only used 1-2 times a week at most.
Lee

 

[AMGeed]

If they have changed the battery then there must be something draining it... My E55 was doing exactly the same....got the message then after 5-10 mins all back to normal.
Changed both battery's with MB ones and not had any messages since fitting a month ago. And the car is only used 1-2 times a week at most.
Lee

The first frosts will tell if the problem is solved.

 

[190]

Even if the dealer did replace the battery as part of the pre-sales prep how long did the car then sit before it was sold ? Just imagine every time a punter opened a door to look at the interior there would be a big current draw that would soon run the battery down. I'd be very surprised if dealers have the time to go around with a charger making sure all their stock have 100% fully charged batteries. They will just make sure it starts which is not the same thing at all. First thing I did when I got my car home was fully charge the battery and it certainly needed it because it took many hours.

 

[AMGeed]

Even if the dealer did replace the battery as part of the pre-sales prep how long did the car then sit before it was sold ? Just imagine every time a punter opened a door to look at the interior there would be a big current draw that would soon run the battery down. I'd be very surprised if dealers have the time to go around with a charger making sure all their stock have 100% fully charged batteries. They will just make sure it starts which is not the same thing at all. First thing I did when I got my car home was fully charge the battery and it certainly needed it because it took many hours.

That's what I'd try too. Just to rule out a duff battery.

 

[grober]

As I said first thing establish the age /provenance and rating/type of the main battery to determine if it has actually been replaced/correctly rated . Only then move on to potential faults. Your battery should be an AGM type if memory serves correct. This will be correct for the cars voltage monitoring systems and alternator charging voltage Sometimes people on the grounds of economy replace AGM batteries with conventional batteries leading to all sorts of weird faults? let us know what you find?

 

[Borys]

Had that message once on my cls....
If you put key in position one in ignition, press trip reset 3 times it will show you Voltage at present
Mine always sits at 12.5v before I start the car which I assume is fine

 

[190]

Mine always sits at 12.5v before I start the car which I assume is fine

That sounds like a good voltage given there is a current draw going on while the voltage is being measured. You can't expect to get the true open circuit voltage for a fully charged battery which would be 12.65-12.7 for a conventional battery or anything up to 13.0 volts for an AGM.

 

[Major774]

I get this all the time despite replacing both batteries. The message normally clears before I've left the driveway, never longer than 2-3mins.

The car has been checked over numerous times with no error codes stored. The BCM software has been updated as per MB's recommendation.

Even if I put the car on trickle charge for a couple of days the message comes back.

My BiL, who ran the service dept in a MB dealership for a couple of years said this was the most common complaint for the E and CLS of that age, especially the 500 and 55k.

If the charging system checks out as healthy one just lives with it...

Have the Aux battery in the engine bay checked out, this often gets forgotten about

I have basically done the same, I just learn to live with it.

Got myself a CTEK charger to cover me if I know the car is going to sit there for 1 week+