E55.........just a flat battery?

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The battery I had in the car when I bought it (Exide) was the same size as the ones shown above. When it went bad I put my Reg# into the ECP website and the Bosch S5 shown in my photos was one of the brands /specs suggested. I've had 4.5 years use out of it so it can't be that bad! Now I have a new one although I realise an AGM one is really the way to go. At the time of buying mine originally, I was offered the choice of lead acid or AGM and I took the cheaper route:wallbash:
Anyone want to buy a brand new Bosch S5 :D

Battry size aside, I still need another alternaor/regulator.
The local indy doesn't open until Wednesday either and I won't risk a long drive to MBS in Southampton with the chance of breaking down in the New Forest or M27.

I will probably get myself a Varta 019 AGM battery from Tanya and sell this new one afterwards.
G14 Varta Start-Stop Plus AGM Car Battery 12V 95Ah (595901085)
 
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That is quite expensive.

Give your MB dealer a call, I am sure it is cheaper.
 
That's a good point actually - the battery in my E55K was huge compared to your battery Rog.

Even in my E320 I have a much larger battery. Although when I had the troubles with it, the battery fitted was smaller. I bought a replacement and had to adjust the bracket that holds the battery in place!

Have had the odd convenience feature message but never failed to start like it did with the old battery.
 
A quick question that is puzzling me. I still have the red Battery warning, visit workshop with two fully charged batteries in the car.
But when attempting to use the SBC HOLD feature I get this message. Does this not point to low voltage in the Aux battery?
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What is confusing me slightly is seeing this video which points to the Aux battery needing replacement and the red warning disappearing?
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I'm still going to get this checked on Wednesday, but the question is bothering me;)
 
Red battery warning is usually the aux battery.

The SBC warning could be the gear selector box, the electronic contacts gets dirty over time. If you scan it on STAR, it should point to the gear selector box. You can either take it apart to clean or replace with a new unit.

When the weather warms up, I need to take my gear selector box apart to clean up the contacts as I got the same SBC warning. There is a thread on here where someone has provided a PDF (I have already downloaded) of what to do, to clean up the contacts.
 
well as I said that's exactly what happened to me (cls55) red battery light every morning after being away fro three weeks but no convenience messages (I never use sbc hold and had not seen the above video or I would have tried it.). Because I had no convenience messages and everything worked, I assumed it was the Aux battery. Replaced Aux battery and all returned to normal as per video. However in my case prior to replacement running the engine for a few mins (ie charging via alternator) boosted the voltage enough to remove the warning if I turned off and restarted. It may be that yours is either more dead than mine or the alternator is not charging properly.
Presumably your heated seats and electric passenger seat motors all work ie have not been disabled? If so I think that too would point to the aux battery providing the alternator is charging.
 
When it went bad I put my Reg# into the ECP website and the Bosch S5 shown in my photos was one of the brands /specs suggested.

I wouldn't rely on ECP. I once sourced a battery for a Honda Jazz using their parts finder and it was blatantly the wrong one when I came to fit it.

I've not used many others but Halfords' parts finders are pretty reliable in my experience.
 
well as I said that's exactly what happened to me (cls55) red battery light every morning after being away fro three weeks but no convenience messages (I never use sbc hold and had not seen the above video or I would have tried it.). Because I had no convenience messages and everything worked, I assumed it was the Aux battery. Replaced Aux battery and all returned to normal as per video. However in my case prior to replacement running the engine for a few mins (ie charging via alternator) boosted the voltage enough to remove the warning if I turned off and restarted. It may be that yours is either more dead than mine or the alternator is not charging properly.
Presumably your heated seats and electric passenger seat motors all work ie have not been disabled? If so I think that too would point to the aux battery providing the alternator is charging.

I get the convenience message this time of yesr if I don't use the car for 3 or more days. Usually goes away within a minute of driving. SBC Hold has always worked on my car so with two supposedly fully charged batteries I'm questioning myself whether the aux battery is now failing (its 5 years old in June).
But I keep coming back to the cluster readout on the dash of the resting readout of the voltage dropping when the engine is started still pointing to alternator.
I hate electrical problems!



I wouldn't rely on ECP. I once sourced a battery for a Honda Jazz using their parts finder and it was blatantly the wrong one when I came to fit it.

I've not used many others but Halfords' parts finders are pretty reliable in my experience.

They are no better for brake pads too I found.
 
I had the convenience messages come up on my E500 w211 on cold mornings if not driven for a few days and as with you it would go out or actually say something like "convenience functions now available" after 5 mins of driving. This is basically saying the main battery is getting weak but a bit of driving boosts the voltage (via the alternator) sufficiently to go above the convenience message trigger level. This is I think quite common as the battery gets older and also happened a lot in my wifes SL R230 (In both cases replacing the main battery totally stopped the convenience messages altogether, whatever the weather or circumstances ;even after 3 weeks away in the winter)
Now that you have replaced the main battery (albeit with a smaller than ideal one ) you are not getting the convenience message. If after a few days use you do get the message then that means that the voltage is dropping in your new battery probably due to lack of or insufficient charging. If you don't get the convenience message then the car is charging the battery and I would look to the Aux battery as the culprit for the red battery light. But easier, and safer, as you say to get your dealer/indie or any good mechanic to tell you if the car is charging.
 
Confirmed this morning at Star Tech I need a new alternator. I'm not going to try the regulator change in the hope it fixes it, and going route 1 and putting a new alternator on.
Ordered this morning through a forum member and will be fitted probably early next week.
Cost?...... New exchange Bosch alternator £191 delivered.
Fitting at Star Tech .......... 2.2hrs labour £182 16 inc VAT.
 
I had the convenience messages come up on my E500 w211 on cold mornings if not driven for a few days and as with you it would go out or actually say something like "convenience functions now available" after 5 mins of driving. This is basically saying the main battery is getting weak but a bit of driving boosts the voltage (via the alternator) sufficiently to go above the convenience message trigger level. This is I think quite common as the battery gets older and also happened a lot in my wifes SL R230 (In both cases replacing the main battery totally stopped the convenience messages altogether, whatever the weather or circumstances ;even after 3 weeks away in the winter)
Now that you have replaced the main battery (albeit with a smaller than ideal one ) you are not getting the convenience message. If after a few days use you do get the message then that means that the voltage is dropping in your new battery probably due to lack of or insufficient charging. If you don't get the convenience message then the car is charging the battery and I would look to the Aux battery as the culprit for the red battery light. But easier, and safer, as you say to get your dealer/indie or any good mechanic to tell you if the car is charging.

I would maybe have looked harder at the aux battery being the culprit, but the readout on the dash dropping to 11.8 with the engine running shows the fault lies with the charging circuit. I will however take another reading of the voltage on the aux battery to see if its holding the charge I put into it.
 
It will probably be fine now you have found the cause. At least its sorted.
 
Confirmed this morning at Star Tech I need a new alternator. I'm not going to try the regulator change in the hope it fixes it, and going route 1 and putting a new alternator on.
Ordered this morning through a forum member and will be fitted probably early next week.
Cost?...... New exchange Bosch alternator £191 delivered.
Fitting at Star Tech .......... 2.2hrs labour £182 16 inc VAT.
All seems very reasonable Roger, could have been a lot worse.

Not ideal timing but at least you found the fault close to home not stranded miles away etc! :thumb:
 
^ Exactly Will. Not a bill I really need just after Xmas, but happy its diagnosed and will be fixed fairly reasonably.

I'll be interested to see what dash reading I'll be getting after the fix. I was getting 13.4 -13.6V when I checked in the summer. That sounds low so maybe not a full charge when I was using the car.
 
She lives again:banana::D

New alternator fitted this morning and all warning lights gone.
Battery reading 12.78V with engine off, 14.2V with engine running on tickover.

In a perverse way, this happening now may have done me a favour.
I have a trip to Heathrow this Saturday and would have been stuffed had this happened during the journey.
I got the old battery tested which failed the CCA test and got a new one under guarantee. Another 3 months and the guarantee was over.
I was unaware there was anything wrong with the old battery and just kept regularly charging it up.

Also, I have a feeling my low battery voltage which I've had for some time was partially down to the alternator not charging the battery properly.
During the summer I tested it and only got a maximum of 13.4V - 13.6V with the engine running.

So a good result and thanks again to merc85 for his assistance getting me a new Bosch alternator at a great price.
 
Alls well that ends well........ The thread will be very helpful to others who will no doubt face similar issues in due course. Glad all back to normal, or better.
 
Just a final post as the car was given a good run up to Heathrow and back this evening, so giving the new alternator and the electrics a good test.
Pleased to say everything is fine now, the charge rate is much higher than before, no warning messages as yet which I would have got by now with the old battery and alternator.
And as a bonus, a decent MPG figure on arrival at Heathrow earlier.
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