Hello all,

I've had my 2017 E350e for 18 months or so now, and love it! Especially the acceleration, and ride.



Warning "Auxiliary Battery Malfunction" came up a few days ago. I took it to dealer - not covered by Extended Warranty and they want over 500 pounds to fix!



​Thought I'd look into it myself, at least to understand what I'm paying for!



​But can't even find the thing!



(According to google they can be in a number of places depending on the car and exact date of manufacture).



Very grateful if anyone can shed any light...

1) where excyly is it located, and how do I get to it (on my car, a 2017 E350e (hybrid), happy to PM vin)

2) what's the part number / cost

3) does it need any coding etc, or once found can I just fit it?



​many many many thanks!



BOGY

 

The VIN would be useful. If it is the motorcycle size battery, it would not cost much more than £100 even as a genuine MB part and high quality after market parts are available at much less. DIY swap should be possible although the battery housing looks odd compared to other MB models.

 

When I try to PM you the VIN, it says I dont have permission. Do we need to be friends first or something?

Be amazing if you were able tell me if my car has the motorcycle type battery or not, or where on earth it is in the car!

Thanks so much!

BOGY

Cold and dark outside now, but really want to find it!??

 

have a look at your passenger footwell under the carpet. MB did away with lead-acid AUX batteries.

Now they use an electronic module to provide energy from a bank of Farad capacitors.

The one I have seen were toasted, perhaps yours can be revived with new $5 parts.

 

Not sure if this forum expects certain number of posts at the forum before private messages are allowed, some forums have that.

 

This is correct for the W213, at least most of them. Never thought it could be different for the plug-in hybrid but parts info claims it should have A0009829208 and this looks like the motorcycle battery which should be at the trunk while the park pawl capacitor would be at the passenger footwell as you say.

Do you have a part number for the capacitor, I missed it from parts info when looking at 213.050 parts (even having filters off).

 

I do not have the P/N. If you see the "motorcycle batt documented" it's very likely it.

Search in these locations:

• Engine bay pass. side
• Dashboard end
• Footwell carpet
• Trunk area

 

Perhaps the capacitor part could be A2059053414? EPC calls it voltage converter but eBay listings call it "spannungsstabilisator start/stopp-system" and it comes with the 421 option code (9G transmission). This part is not listed for a 213.050.

 

I believe this video it pretty good.


I hope it helps!