Guess oh meter going down quickly

B-Class Electric Drive Forum

Help Support B-Class Electric Drive Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Woosty

Member
Joined
Mar 10, 2021
Messages
10
Hi all, I have a 2018 B Class electric

My question is: when I first drive the car after a full charge the GOM seems to go down by a quarter after only a couple of miles.

Is this normal?

Many thanks,

Chris
 
Woosty said:
Hi all, I have a 2018 B Class electric

My question is: when I first drive the car after a full charge the GOM seems to go down by a quarter after only a couple of miles.

Is this normal?

Chris,

I'd say is not abnormal. I see the same when I unplug from the EVSE. As the GOM is a predictive tool it tries to anticipate range-to-empty on current driving behavior. The vehicle was not moving during the charging and it quite likely over estimates the range, and then corrects as you start to drive.
"by a quarter"? Are say that a full charge, of say, 85 miles range falls to about 60 miles after driving just a couple of miles?

Today I did my weekly B250e charging, and the session stopped at 100 miles range (I had hit the extended charge button), by the time I got home, about 11km/7miles actual distance and mostly in the HOV lane at a constant 65MPH, the range had settled to 89 miles, plus a bonus of 2.5miles on the ECO display. This to me is "normal".

Peter,
 
Chris,

The GOM is aptly named. Like all range calculators, it uses the last bit of driving to estimate remaining range on the assumption that the remainder will be exactly the same. Never really true if you think about how you drive as you approach your home after a day of driving.

Particularly if you are a newish owner, there is also the phenomenon of newbie lead foot. What fun it is to step on it initially to feel the kick of the torque. This degrades range. Last, depending on where you live climate wise, the car's battery needs to warm up before it hits its optimal range. So early on, it is worse. Worsened if you are heating or air conditioning the car to reach your preferred temperature. Then after all that, the car settles in and performs better range wise. The other factors are highway vs stop and go. There was one owner who had a sharp elevation change from home to work. Going one way, he coasted a lot and got great range. Going the other way, it ate range more rapidly.

There are other more explicit posts on this topic if you want to delve into the more technical explanation.

In any case, welcome to the club. Enjoy the ride!
 
Thanks for the replies, I do tend to drive with a heavy foot but the GOM goes down to a quarter when I just pop to the shops for 3-5miles driving gently.

Do you think I need to book it in with Mercedes or if you can recommend a better place locally (Tamworth, Staffordshire)

Thanks again,

Chris
 
Woosty said:
Thanks for the replies, I do tend to drive with a heavy foot but the GOM goes down to a quarter when I just pop to the shops for 3-5miles driving gently.

Do you think I need to book it in with Mercedes or if you can recommend a better place locally (Tamworth, Staffordshire)
Chris,

Would you mind taking a PIX of the GOM and the "Battery Guage" after a charging session and again when "GOM goes down to a quarter"?

I'm not sure I understand what you are seeing, and your concern that there may be an issue with your B Klass.

Peter,
 
Chris,

Hm, that would be unusual, yes. If you take it to a shop, it needs to be a shop that can plug into the onboard computer and read out the error codes to identify the source of the fault. If just a software fault, I am not too worried for you. However, my main point of investigation is to satisfy that you are getting the maximum charge possible into your batteries and that your batteries are operating at 95+ percent efficiency. Batteries degrade over time and if too aggressively charged up, i.e. using the range extender all the time. To maintain the battery warranty in the U.S., the owner is required to bring the car into the shop and have the technician run the annual battery test.

The other thing you should know if you don't already is that when the temperatures are below 40 degrees, the range of our B250s is in the 60 mile vicinity. We only get into the 80s and above 90 miles in the more temperate summer months. If that fits your temps right now and you are getting 60 miles per charge, that is normal in my book. I never got into the 70s in the winter months over 6 years.

So the net of all that is whether it is a harmless software thing or a real problem with your battery which I doubt but it can be checked out by an EV certified MB mechanic.
 
Great info thanks, I’ll fully charge it tonight and then take pics and record mileage of GOM going down.

Really helpful, thank you

Chris
 
Hi all, thanks for the replies.

Thought I’d update you, I reset everything and the GOM went down much slower with the following stats.

I think it was probably just because I usually drive ‘spiritedly’

10miles, 1.6mpkWh @ 18mph and had an indicated 71miles left on the display.

Cheers for all of your help,

Stay safe,

Chris
 
Back
Top