Anyone know the manufacturer of the OEM E55 batteries..???
MBWorld Fanatic!
Joined: Mar 2008
Posts: 1,230
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From: Vancouver, BC
CLS55 AMG
well i went out and got a new battery today, all the errors went away, but the car still only shows 12 volts at idle... should be around 14.4 right? i also smell a weird burning electronic smell coming from the front, i'm guessing it's the alternator dying... ****ty thing is that i just bought my warranty and it has a 30 day AND 1000 mile waiting period before I can make a claim... hopefully i can drive my car for 30 days/1000 miles before the alternator craps out completely
MBWorld Fanatic!
Joined: Mar 2008
Posts: 1,230
Likes: 32
From: Vancouver, BC
CLS55 AMG
here's a video of my voltage... it stays around 12 at idle, as soon as i give it any gas, it shoots up to 13.xx no problem... i guess my alternator is slowly dying.
http://youtu.be/D-rVfIXByGc
http://youtu.be/D-rVfIXByGc
Thread Starter
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Joined: Mar 2011
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From: The Granite State
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here's a video of my voltage... it stays around 12 at idle, as soon as i give it any gas, it shoots up to 13.xx no problem... i guess my alternator is slowly dying.
http://youtu.be/D-rVfIXByGc
http://youtu.be/D-rVfIXByGc
It sounds like a charging issue for sure. You should be at 14.4V when the engine is running.... Bad batteries will eventually kill the alternator/regulator. The alternator is NOT designed to recharge dead batteries, it's intended to run the car and provide small charge to the battery as needed.
-G
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Joined: Sep 2010
Posts: 119
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From: Arizona
2004 E55 AMG
Amazon sells high CCA Braille Batteries B10049 for the main and B14115 for the backup. They are not cheap but we do own a AMG. In cold weather you are looking at 1520 CCA vs 900 CCA for the main and 306 CCA vs 220 for the backup. 
They are sealed AGM just like the OEM.
They are sealed AGM just like the OEM.
Last edited by AMG903L; Apr 30, 2012 at 10:43 AM. Reason: add
MBWorld Fanatic!
Joined: Jan 2011
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From: West
E55 AMG
I have that same rear battery after the OEM Varta took a dump. Works well, just make sure you properly charge and condition the battery prior to install. At 2AMPS it took nearly 8 hours on mine.
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From: Arizona
2004 E55 AMG
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From: Florida-Germany-New York
2004 E55,1969 300SEL6.3,2011 ML350 BlueTec Diesel,2005 ML400 CDI
The AUX front battery only charges from the alternator. It's purpose, as I understand it, is to act as a UPS for the electronics. When you start the engine the electronics are taken off the mains before the starter is engaged and are supplied a constant voltage from the AUX battery while the starter is engaged to protect them from low voltages which can cause catastrophic damage to some components. The electronics are then returned to the mains after the starter disengages. I did not know this until Yacht Master sent me the MB schematics.
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2003 CL55 AMG
My attempts at a fix thus far:
Tested both batteries - checked out fine
Replaced rear battery with brand new one
Replaced voltage regulator on alternator
Nothing has fixed it yet. The alternator isnt old, and my BCM has the old part #.
My issues differ from yours, only that I have 12.3 before starting. It starts fine, stays at 13.6 or so around cold start idle. Once I put it in D, the voltage gets to 12.8, then eventually falls bellow 12.
Reving it brings it back up to 14.1, even driving I see 14.1, but lately, even driving at speed, the voltage dips below 12 and convenience functions turn off. Sometimes it goes back up to 14.1 instantly, other times it stays under 12. I get the battery light all the time now.
Tested both batteries - checked out fine
Replaced rear battery with brand new one
Replaced voltage regulator on alternator
Nothing has fixed it yet. The alternator isnt old, and my BCM has the old part #.
My issues differ from yours, only that I have 12.3 before starting. It starts fine, stays at 13.6 or so around cold start idle. Once I put it in D, the voltage gets to 12.8, then eventually falls bellow 12.
Reving it brings it back up to 14.1, even driving I see 14.1, but lately, even driving at speed, the voltage dips below 12 and convenience functions turn off. Sometimes it goes back up to 14.1 instantly, other times it stays under 12. I get the battery light all the time now.
what was your electrical issue? I am having a similar problem with my 2003 Mercedes cl55. rebuilt alternator with oem regulator. replaced main battery twice. I am wondering if I should use a AGM battery this time?
