Poor range performance

[bcurious]

@ClassESage I live in Southern California. It was about 70 on my way into town and about 75 on my way home.

As reported earlier, in Maryland, my GOM has been usually displaying 66-71, with temperatures mostly in the 20's and 30's. My driving is divided about 60-40 highway-city with 2.3-2.4 mpkWh.

Has anyone compared B-class range versus temperature relationship? HarleyMYK's experience versus mine seems to suggest relatively minor effect of temperature.

Are those readings of 66-71 observed after parked in a semi-heated garage space, or outdoors in the 20s and 30s?
Here in the 0s to 10s overnight, outdoors, I'm observing 56.

I wonder what people with the Range Extender function, when switched on for a loading cycle, observe in the cold.

 

[ClassESage]

The car is parked in an attached unheated garage, so yes, it is 10-15 degrees warmer than outside when starting. Presumably, the batteries equilibrate to the outdoor temperature soon after departure...?

@bcurious, what mpkWh's do you observe at those extremely low temperatures and with what driving style/terrain?

Given that the B-class shares Panasonic batteries similar to the Model S, I wonder how the range/temperature profiles compare?

 

[bcurious]

The car is parked in an attached unheated garage, so yes, it is 10-15 degrees warmer than outside when starting. Presumably, the batteries equilibrate to the outdoor temperature soon after departure...?

I would concur about the equilibration, and my unstated presupposition was that a higher than outside air temperature parking location may influence the GOM reading away from what its reading would be if parked at the "aussentemperatur." Perhaps if your reading has been taken at the "still warmer" time of usage it is reflecting something different than if one took the reading from that if the B-class had been parked outside. I'm not familiar with the logic that the GOM employs.

@bcurious, what mpkWh's do you observe at those extremely low temperatures and with what driving style/terrain?

Given that the B-class shares Panasonic batteries similar to the Model S, I wonder how the range/temperature profiles compare?

My wife is the primary driver of the B-class, and I haven't taken the chance yet to satisfactorily monitor this reading yet. She is awarded the eco 100% rating daily, fwiw, but the drive is spent roughly 80% of the time at relatively constant highway speeds. I'd say that the driving style has been conservative and the terrain moderate. Under 800' of elevation U.S. east coast river valley stuff...probably not atypical terrain for these vehicles.

I'll see if I can come up with a mi/kW-h figure over the next week.
I do suspect that the colder temperatures have greater effects on the battery charging than they do on the energy usage while in motion, snow excepting.
I consider the recent temperatures cold but not extreme, it is not an outlier year here when it does reach -30F here overnight for a few consecutive nights, and that is what I would consider our extremes of "normal" temperature. Our northern New England correspondent(s) face this more often than I.

 

[JupiterRed]

I'm extremely disappointed with the range that my wife and I are getting. We live in Connecticut and it's been cold. Temp's in the 20s and sometimes 30's. The most we get on a charge is 55 miles. Cold definitely effects range. I hope when it warms up we get better performance.

Lucky for us, her driving habits are small trips that end up at home where we can charge again.

 

[TheStig]

We also live in CT, now I'm concerned the range is going to be more of a concern. Do you keep yours in a garage? On the coldest of days our garage is in the low 50s high 40s so I figured that would help range somewhat. If we did a B class it would not see a regular commute, just shuttling kids and groceries around town for the most part.

Maybe the range package is a nessesity in cold states. Might use it more or all the time. Do you have that?

 

[wtzouris]

I'm just outside NYC, and getting about 80 miles of range in sub-freezing weather -- but I always use range extending mode. I think it adds about 10% more charge. So my first 7 miles of my commute I am still at 100% SOC. Then I go on the highway and it switches to 99%. In essence, I feel like I am starting at 110%. So when I get to my work, 29 miles, I'm at 77% SOC (33% used from my theoretical 110% starting point) , and the one time I didn't charge at work I drove home from 76% to 31% SOC (45% SOC used). On my ride home I always use more "consumers" like heating and I usually have another passenger for half the ride. On my way into work I am careful to avoid using the heating system. So one of these days I am going to do this round trip using a standard charge. My guess is that I will use up 80% overall and have 20% remaining -- a little too close for comfort IMO. I'm saying 29 miles takes approx 40% SOC, on average. That's how I come up with 29 miles divided by 0.40 gives a 72 mile range with standard charge and 80 mile range with extended charge.. I guess I average 2.0 - 2.5 mpkWh but I really don't believe that meter is accurate. I will update as I do more commuting with the car.

 

[wtzouris]

So I did the 7 mile trip to the highway entrance again on a standard charge, same driving settings as usual. The extended charge changes the useable kW of the battery from 28 kW to 31.5 kW from an actual 36 kW battery-- I was at 90% when I got to the highway ramp - (7 miles) on a standard charge. I then drove a total of 42 miles today with the heat on the entire time @ 68 degrees fan speed on 2, and I used 55% SOC on a standard charge. So that would be a 76 mile range. 2.4 mpkWh I always use E or E+ mode. Usually E+ on the way to work, E on the way home. The extended charge would add 7 miles, or about 12%, for a total of 83 mile range. It is 34 degrees F today.
It has been suggested that that number should be multiplied by 1.2 because Mercedes calculated the mpkWh meter as WTW (Wall to Wheels) to account for charger efficiency. So 3.0 mpkWh is really 3.6 mpkWh. - W

 

[TheStig]

Wow you keep a lot of details on your range. I guess in the end in our use of the car for around town and short trips with a 40amp charger it will be fine. It will just be these few cold months where the range is on the low end I hope. Come spring and fall it will be better, we'll get the range all those folks in California get year round. Summer maybe not, I heard heat can impact range too but maybe not as bad as using the heater for a cabin and battery.

 

[JeffRay]

I too was initially disappointed not to get the advertised 87 range but closer to 50-60 depending on outside temperature, given mostly urban stop and go driving.

I have a 2014 so no range extender. Live in NYC so have experienced the limited range as others have and have posted. I came to a realization the other night, so what! For what I bought it for, in city and occasional jaunt out to Long Island, Westchester or NJ, what I need to alleviate range anxiety is 1) a little planning and 2) real convenient charging. Like a lot of new electronics (this is a big electronic) daily charging is now assumed or else. For me, not being in a house with a garage, it means watching the range and charging either at a) the dealer near work (go fetch after work), b) the charging station garage near home (go fetch next morning) or like Friday c) the charging station at our satellite LI office (plug in on arrival, unplug after lunch). The two close calls since I picked up the Be on 12.1 were plugging in with 1 mile and another time with 2 miles at the dealer. Not looking forward to running out of volts and waiting for AAA (or MB). No clue what they would do other than tow me to the dealer. I do envy those owners who live in suburbia and have a heated garage for this issue.

I admit that if one's driving is more varied, i.e. going to different places all the time, this would be a headache not worth taking on. For most of us, the question is whether it is worth the retraining. I don't miss the regular trips to NJ to fill up the gas tank twice a month. Having to think about when I have to charge is not that tough. I am going to hang in there and hope to enjoy the extended range when the weather turns warmer with goal of once a week charge if I can get 87 mile range.

 

[JupiterRed]

We also live in CT, now I'm concerned the range is going to be more of a concern. Do you keep yours in a garage? On the coldest of days our garage is in the low 50s high 40s so I figured that would help range somewhat. If we did a B class it would not see a regular commute, just shuttling kids and groceries around town for the most part.

Maybe the range package is a nessesity in cold states. Might use it more or all the time. Do you have that?

My car is garaged and its side 40's in there most days. It doesn't really seem to help. I'm going to try to delay charging until 4AM so the car will be fully charged when my wife takes it at 8am.

 

[mtodd3]

I got my Be about 3 weeks ago, and see similar 50-60 mile ranges (Philadelphia temperatures of 20-30F). With mostly short trips, this has not been a problem, although it is watched closely.

I do notice that the first mile is as low as 1-1.2 m/kwh but that this increases to 1.5 by the second mile (daycare drop-off with a dozen speed humps). After another 2 miles to work, it's up to 1.7-1.9 m/kwh. I pre-warm while in the unheated carriage house, but only have 110V charging at this time. I'm not confident about the knob-n-tube wiring handling higher current.

On longer trips (5-10 miles), the average increases to ~ 2 m/kwh at these same temperatures. I usually get close to 100% rating for acceleration and braking, about average for "steady driving" but that's the commuting path: lights, traffic, hills, etc. I suspect the warming of the batteries gives one increased efficiency just like a gas-engine...low for the first few miles, but increasing once the battery is more active. This means short errands with time to cool off are the worst case scenario for maximum efficiency

Like others, I expect this will increase once warmer weather arrives.

 

[rdavis0521]

I will admit, I don't have to fight the cold, and it definitely seems that this has a very negative impact. I typically run at least 2.9 (as per the gauge) to 3.2 miles/kWh. I will admit, it is very easy to make that lower fall quickly. You have to drive very conservatively to get those kind of numbers. No jack-rabbit starts, coast when possible rather than using regen.

Although I don't have much need to use the heater, I typically do have climate-control on, and generally it's A/C.

The word I've heard from other cold weather drivers is: (1) pre-heat, and (2) don't use the heater while driving, but use heated seats which take less power. But, if you're getting 1.5kWh, there is definitely light at the end of the tunnel when it warms up. You should be able to get almost double that.

Ray

 

[JupiterRed]

I got my Be about 3 weeks ago, and see similar 50-60 mile ranges (Philadelphia temperatures of 20-30F). With mostly short trips, this has not been a problem, although it is watched closely.

I do notice that the first mile is as low as 1-1.2 m/kwh but that this increases to 1.5 by the second mile (daycare drop-off with a dozen speed humps). After another 2 miles to work, it's up to 1.7-1.9 m/kwh. I pre-warm while in the unheated carriage house, but only have 110V charging at this time. I'm not confident about the knob-n-tube wiring handling higher current.

On longer trips (5-10 miles), the average increases to ~ 2 m/kwh at these same temperatures. I usually get close to 100% rating for acceleration and braking, about average for "steady driving" but that's the commuting path: lights, traffic, hills, etc. I suspect the warming of the batteries gives one increased efficiency just like a gas-engine...low for the first few miles, but increasing once the battery is more active. This means short errands with time to cool off are the worst case scenario for maximum efficiency

Like others, I expect this will increase once warmer weather arrives.

I'm in CT. Have the same experience. I do have 220V charging however but the experience is the same.