Auxiliary battery malfunction

Tiny
DTRAIN46
  • MEMBER
  • 2010 MERCEDES BENZ E350
  • 3.5L
  • V6
  • 4WD
  • AUTOMATIC
  • 100 MILES
I've changed the alternator twice and charge the battery to the full capacity and the auxiliary battery light still comes on.
Do you
have the same problem?
Yes
No
Monday, August 12th, 2019 AT 12:23 PM

15 Replies

Tiny
BMDOUBLE
  • EXPERT
You will need to replace the auxiliary battery located in the trunk area. I've attached pictures with instructions.
Was this
answer
helpful?
Yes
No
Monday, August 12th, 2019 AT 12:46 PM
Tiny
DTRAIN46
  • MEMBER
I have check the trunk, but it's not in there.
Was this
answer
helpful?
Yes
No
Monday, August 12th, 2019 AT 1:00 PM
Tiny
BMDOUBLE
  • EXPERT
Then yours may be mounted in the dash on the driver s side. It s the size of a power wheels battery, super small. The panel at the driver side knee area and the small panel on the left side of the dash accessible when you open the door, pop the panel out and remove the 10mm bolt and the battery will drop down so you can grab it from below the dash. Some E classes have it in the trunk area and some on the driver side dash area.
Was this
answer
helpful?
Yes
No
+1
Monday, August 12th, 2019 AT 5:19 PM
Tiny
JIS001
  • EXPERT
Hello, just wanted to jump in as well. As BMDOUBLE stated earlier, the auxiliary battery should be in the luggage compartment. Mercedes gives a poor diagram as to the exact location but it looks like you will need to remove the trim covers to actually see it?

I would recommend you get an advance scan tool and do a full system scan to see what codes may be posted. Once you have those codes we can further assist. Also when I mention a scan, I do not mean those quick scans you get from the parts stores. You only get engine and maybe ABS codes. I am talking about a full scan where it scans every module in your vehicle.

Let us know if you find the auxiliary battery after removing all panels in trunk or if you can get the whole computer system scanned.
Was this
answer
helpful?
Yes
No
+1
Monday, August 12th, 2019 AT 11:06 PM
Tiny
DTRAIN46
  • MEMBER
Yea, I looked it up and it looks like it might be under the driver side dash.
Was this
answer
helpful?
Yes
No
Tuesday, August 13th, 2019 AT 4:26 PM
Tiny
DTRAIN46
  • MEMBER
It's a 2010 e350 4matic.
Was this
answer
helpful?
Yes
No
Tuesday, August 13th, 2019 AT 4:26 PM
Tiny
DTRAIN46
  • MEMBER
Does it have to be a Mercedes battery? Because they have them at battery's plus but the are Duracell.
Was this
answer
helpful?
Yes
No
Tuesday, August 13th, 2019 AT 4:39 PM
Tiny
BMDOUBLE
  • EXPERT
As long as it s the same physical size and volts, it will work.
Was this
answer
helpful?
Yes
No
Wednesday, August 14th, 2019 AT 8:35 AM
Tiny
DTRAIN46
  • MEMBER
Okay, it's a little smaller and more volts. Is that okay?
Was this
answer
helpful?
Yes
No
Wednesday, August 14th, 2019 AT 1:37 PM
Tiny
BMDOUBLE
  • EXPERT
Volts or amp hours? It needs to be 12 volts.
Was this
answer
helpful?
Yes
No
+1
Thursday, August 15th, 2019 AT 10:03 AM
Tiny
DTRAIN46
  • MEMBER
Is it okay to drive it until get the battery?
Was this
answer
helpful?
Yes
No
Friday, August 16th, 2019 AT 2:44 PM
Tiny
BMDOUBLE
  • EXPERT
Yes you can still drive it.
Was this
answer
helpful?
Yes
No
Friday, August 16th, 2019 AT 3:18 PM
Tiny
DTRAIN46
  • MEMBER
Good, because I haven't driven it for weeks now. Tired of driving my truck. Just got to get that battery now. Thanks
Was this
answer
helpful?
Yes
No
Friday, August 16th, 2019 AT 4:28 PM
Tiny
BMDOUBLE
  • EXPERT
Roger that!
Was this
answer
helpful?
Yes
No
Friday, August 16th, 2019 AT 8:50 PM
Tiny
ELSAGEORGE
  • MEMBER
I was facing the same issue and came across this blog, it also helped me a lot to identify where auxiliary battery is located and how to install it.

https://xenons4u.co.uk/blog/mercedes-benz-auxiliary-battery-malfunction-explained/
Was this
answer
helpful?
Yes
No
Monday, September 16th, 2019 AT 4:35 AM

Please login or register to post a reply.

Sponsored links