spinn

I left my lights on the other morning and came back to a drained battery (4th time since buying the car last year). After giving it a jump start, I got the red visit workshop light. The main battery has a standing voltage of about 12.0 volts and about 13.5 volts while running. I tried to check the aux battery, but was getting weird readings, which I don't know why it's wrong. I have not received any other message of certain components not working due to low voltage...is it likely my main battery is too low now?

rchase

Thanks for the info, dealer wanted 150.00 for battery and 150.00 for install on this haha

06E55

For those that replaced their auxiliary battery, did you guys disconnect the main battery prior to installation?

mtrevelino

No. Just be careful with the cables when you pull them off the auxiliary battery.
Mike T.

06E55

Anyone have experience with Carquest's auxiliary battery? I have one on order (they didn't have the right one in stock) and it will be delivered tomorrow... I know Carquest has an OEM main battery (bought one of those last month)...

http://www.carquest.com/webapp/wcs/s...82_?acesApp=0#

moosejaw

Ironic that I found that a 2009 E350 doesn't have the AUX battery

starbrite

Why is that ironic? Well know fact.

moosejaw

It is?
The only thing a E350 doesn't have is automatic climate control?

06E55

Well, I picked up the battery this AM... Installation took 5 minutes starting by removing the old battery and installing the new one... I think the hardest part about the dang install is getting that cabin air filter assembly just right...

Problem solved.... No more convenience features disabled BS....

S2K750

Soon to follow... DIY, filling gas!

06E55

Well, I guess I spoke too soon... The next morning I started the car and got the message again... Same thing that evening, this morning, and this evening. I had the alternator replaced in August following a car accident (which was when all of this mess started). The service advisor confirmed that the voltage regulator came with the new alternator and was change on this date. Both the main batter and auxiliary battery have been replaced since getting the car back (both batteries are from Carquest). I am beginning to think that the alternator, and both batteries weren't bad in the first place... The local stealership is going to run some diagnostics on it next Tuesday... Service advisor assured me they wouldn't charge me for the diagnostics since the problem wasn't correctly fixed in the first place. I am hoping they can attribute this to the accident and I can get refunded the cost of the alternator, since it wasn't covered in my insurance claim...

06E55

Well, my vehicle ended up dying at no other place than.... the MB dealer while I was test driving the 2014 S Class for the day last Friday... I returned the vehicle after a few hours only to find my E55 wouldn't start, all displays dead, no electronics working... I had an appointment scheduled for yesterday, but they worked me in early... I picked up my car yesterday and everything appears to be fine... Apparently some wire leading to the pre-fuse box was loose... Would have been nice if they found this when they replaced my alternator... Oh well, at least I won't have to worry about my batteries again for as long as I own the vehicle... And they didn't charge me again for the diagnostics...

RobE55

Hello AMGers...

Winters a coming. Checked my 2 battery's and the main was well at 12.55V but the aux was a dismal 10.3V bought one at the local but made sure it was a AGM and fit right. Thanks to the forum search all you do is remove and replace. Didn't have to jumper it. -- NO codes or other gizmos to go awray. Its all good.

Check yours TODAY!!!

Rob

ThroughTheEsses

This thread is invaluable if for no other reason than it lists the form factor needed for the aux battery. The pics are just gravy Thank you!!!

Was having electrical gremlins lately and woke up to a dead primary battery anyway. Figured I'd replace both. Neither sears nor autozone had the Aux battery info in their systems. But given the group size, Autozone actually did carry both primary and aux form factors. So All good! All gremlins gone!

Thanks MBWorld!

SuperChargerE55

Please anyone how do I proceed if want to replace both batteries do I start with rear then front or other way or just disconnect both at one time in such case which one first?

I searched is so many threads but not a sinle one about this

CharlyE500

Reviving the old post. Not sure which one to chose. ET14B, ETX14 and ETX 14L.
Anyone knows ? thanks.

Ls1toAMG

I used the Duralast Platnum from AutoZone. Same price.