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2014 E350 SPORT 4MATIC (2 batteries)

Old Sep 1, 2013 | 08:37 AM
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MLRLINCOLN's Avatar
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2022 MB C300 4MATIC
2014 E350 SPORT 4MATIC (2 batteries)

Just picked up my new Benz last week (8th one) and was wondering if anyone knows the purpose of the 2nd battery in the trunk?

It doesn't seem to mention anything about it in the manual.

My guest is it has someting to do with the ECO mode.
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Old Sep 1, 2013 | 09:18 AM
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Originally Posted by MLRLINCOLN
Just picked up my new Benz last week (8th one) and was wondering if anyone knows the purpose of the 2nd battery in the trunk?

It doesn't seem to mention anything about it in the manual.

My guest is it has someting to do with the ECO mode.
You sure you have one under the hood too?

I have one battery in the trunk in my 2010 model E550. In my previous 2011 E350 battery was under the hood but invisible.
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Old Sep 1, 2013 | 10:56 AM
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Correct, ECO start/stop auxiliary battery.
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Old Sep 1, 2013 | 05:31 PM
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2014 MB E350 Luxury
I believe I read somewhere that it retains settings in computers when the primary battery is removed or dead.
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Old Sep 1, 2013 | 05:44 PM
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Originally Posted by dwright10
I believe I read somewhere that it retains settings in computers when the primary battery is removed or dead.

And if it is the same physical size as the main battery it adds about 50 lb extra weight to the car "helping" with all those environmental issues that the eco system is for, i.e. makes the car heavier each time it has to start moving from the stop. And I heard that starter motor is also bigger and heavier than the standard one...

Extra weight in the car with "priming" the cylinders probably offset all the savings that the car engine is at stop compared to idle that uses very little fuel.
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Old Sep 14, 2013 | 07:01 PM
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Originally Posted by Arrie
And if it is the same physical size as the main battery it adds about 50 lb extra weight to the car "helping" with all those environmental issues that the eco system is for, i.e. makes the car heavier each time it has to start moving from the stop. And I heard that starter motor is also bigger and heavier than the standard one...

Extra weight in the car with "priming" the cylinders probably offset all the savings that the car engine is at stop compared to idle that uses very little fuel.
Mine is a very small battery in the rear, smaller than a motorcycle battery.
I had to hunt to find real battery under the hood. I didn't take the main battery's cover off there is a special connector there if you want to charge it or jump it. I have a 2014 E350 Cab just got it.
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Old Sep 15, 2013 | 12:35 AM
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I'm going to have to check mine tomorrow, didn't know there was a second battery in my car...
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