Winter is around the corner; performance differences

[JeffRay]

For those that are experiencing their first winter in the Be250, this is a good thread. Today, I went out having activated the remote climate control and the car was still cold. Must be doing something wrong. I then did as WTZouris suggested and turned on the heated seats and windshield for a few minutes. I was a little shocked when I read it was 15 degrees out as I missed that forecast.

Anyhoo, plugged into the office 110v at a measly 1.2 kwH recharge rate. Will be interested to see what this winter requires in terms of full top ups.

 

[kinabalu]

How are you guys measuring your per kWh efficiency? I'm seeing people post things about mpkWh of 2.5 - 3 but no idea how you get these numbers?

And someone said they were doing 115mi during the summer? I live in CA which its always summer (except for actually getting what we'd call winter of late). The farthest range I've gotten so far is 93mi (albeit with a lot of hills throughout).

And the climate control ... I see it on the webapp but don't have any idea how it works, can you set a specific temperature because it doesn't appear so?

All-in-all loving the B, can't wait to get an EVSE at the house, will make the dread of 110v charging a thing of the past hopefully!

 

[jwarcd]

I've done 115 miles in the summer (80-90 deg F, 85% highway) with about 12-15% battery left at my destination. Whenever I do long trips, I use range plus charging mode. I drive pretty conservatively, keeping the %power display in the "economy" area when accelerating, max speed of 65mph I use D+ on highway to allow coasting down hills. I don't use cruise control since it will cause the car to use regen when going down hills to keep the car at the mph set point.

Today I did my first longer 86 mile "winter" drive (11-29 deg F, 80% highway). 2.8 mpkWh reported on instrument cluster (multiply by 1.2 to get the 3.36 actual mpkWh), average of 50 mph, with 15% battery left. I charged with Range Plus enabled, used climate control preconditioning. Since this was my first longer winter trip I didn't know if it would make it so I turned off the heat for the first 30 miles. At 30 miles I turned on the heat (60 deg) and the battery % dropped about 4% pretty quickly over the next few minutes, but then retuned to a more normal rate after that. I should have used the heat from the start since it seems not to use too much battery once it reaches the temperature set point. I probably only saved a few % by not using the heat for the first 30 miles.

 

[kinabalu]

Interesting, so I was watching it today and I was averaging about 2.4 mpkWh (lots of hills where I live, and somewhat steep grades at times).

Why are you multiplying that number by 1.2 btw?

And is there something specific about the car using regen? I use D- a lot so it regens the battery, but you mention something about mph set point. I have no idea what that is?

Thanks! And it's always good to hear stories about that. 115 miles with 12-15% battery life left is pretty damn good. I did 93mi coming back from a 110mi trip and ran it to near empty, long story.

 

[jwarcd]

The mpkWh value shown on the instrument cluster is using the kWh that was supplied by the power grid to charge the battery, not what was actually stored in the battery. Since the charger is not 100% efficient, not all the power supplied by the power grid makes it into the battery. Most other electric vehicles will show you the mpkWh value using the battery kWh. If you multiply the value shown on the instrument cluster by 1.2 you will get a mpkWh value that you can use to compare to other types of EVs.

The mph set point I was referencing is for the cruise control. It's more efficient to coast rather than using regen, but the cruise control will always try to keep the car at mph set point. So when going down hills when cruise control is active the car will use regen to slow itself down which is less efficient than coasting. Around town I use D- as well since I like control I have over regen.

 

[Stretch2727]

I agree with the range hit on cold weather short range driving but it is not as bad on longer trips once the battery is warmed up.

Did a trip last weekend.

Start temp 42 Degrees
End Temp 48 Degrees
Extended Charge before leaving.
86 Miles Round Trip
End Battery State 21%

I was a little worried we would need to stop to charge but that did not turn out to be the case. There are 2-3 chargers on the route home so I had a back up plan just in case.

We stopped for about 2 hours at the destination. (no charging).

Average Speed was 40 MPH and we got an indicated 3.0 Miles/kWh.

It is a pretty good route for efficiency. Lower speeds, some red lights but not too many.

When I started indicated was 1.2 miles/kWh but after 3-4 miles it began to climb.

This is and actual 297 watts/mile or 3.37 miles/ kWh assuming the extended range battery capacity of 31.4 Kwh. Drives me nuts that the MB does not indicate miles/kWh correctly.

Calculated Range 105 Miles. (3.37 * 31.4 Kwh)

So the MB has pretty good range in moderate cold temps as long as you are not stopping and letting the battery get cold again. The route also helped as it is not high speed or does not have a lot of stop and go.

One other thing I noticed. The GOM was at 57 miles when we started and 45 miles at the mid point. So we drove 43 miles and it indicated we used 12 miles of range. (Part of the reason for the discrepancy is it does not consider the extended charge.) This is how messed up the mileage meter is on the MB.

 

[camaroguy]

Stretch, the GOM does account for extended range. In fact this is the only way you can tell after the car has charged, whether or not it is range charged (which is super annoying in itself). The range continues to go up after you it 100% SOC if you are still charging on a range charge.

I have been hoping for mileage that you have posted, but never come anywhere near it. Its been in the 30's lately, and its usually raining/dark so the lights are on. I guess these have a pretty big effect. We try to leave the heat down at 68, but 60 is just too cold for the baby and wife. We will soon attempt a 70 mile one way trip on the freeway and see how it goes. There is charging on our way, and at the destination if we end up needing it.

 

[JeffRay]

With overnight temperatures in the 40s here, I thought I would reread this thread.

Today, not so bad but I turned off the climate control to conserve the battery so I could make it to my weekly charge this weekend.

 

[Stretch2727]

Ah yes winter again....

I pretty much completely ignore the GOM so not sure if it accounts for the extended charge. Trust me it is guessing way low.

One trick in the winter time is to charge just before you leave. It helps warms the battery.

On short trips the efficiency is pretty bad in the winter no matter what I do. Does not matter so much as it is a short trip.

On longer trips I find it is not so bad as eventually the battery warms up. I have to drop the wife at the airport end of October, 50 miles each way...pretty sure it will do it round trip without a re-charge. I continually look at the % battery used versus miles traveled to guesstimate the range. 25% battery used, 25 miles traveled = 100 miles of range.

On the highway I use D+ this way it just coasts when I leave off the accelerator. Try to avoid the brake. In town I use D- so I am sure I a braking with regen. Try to avoid the brake.

 

[JeffRay]

Great reminders Stretch.

Well, weather hasn't gotten worse than high 40s overnight so no issues this week. Good to be prepared.

This weekend, have to winterize my outdoor terrace plants. Less fun than driving the MBe.

 

[GlennD]

What is this winter thing. Is that when the temperature dips into the forties?

 

[JeffRay]

OK socal Glenn, rub it in again. BTW, headed out to lovely LA and SAN in a couple of weeks so plan to bring my sun glasses.

 

[JeffRay]

With overnight temperatures dropping into the 30s finally, it has affected my morning commute efficiency. I remind that I park outside on the street with no ability to plug in to warm up the car before heading out.

Back to twice a week charging. Costs me $10 per chargeup to charge at most commercial chargers.

 

[JeffRay]

Well, winter is here in the Northeast at least. Last night, the low was 25 degrees F. How does that affect range and my driving habits you ask? Well here are some thoughts for the curious.

1. I drive my ICE wagon all chilly mornings so I can warm it up and run the heated seats in the front and the aftermarket heated seat pads in the rear. Then off to drop off at school and onto work. If the overnight was above 40 degrees F or I happened to park the B250e in the indoor parking lot overnight, I will drive it in the morning. It also has aftermarket heated seat pads in the back.

2. Range drops to 60 miles at most, so forces a twice a week full recharge even if I plug into the work 120v outlet while at work. By driving the ICE wagon some days, can limit my full recharge to once a week.

3. Fridays, I drive my B250e to work for full recharge over 24 hours. Swing by over the weekend to pick it up. Oh yes, I hit the range extend button to charge up to 112.5%.

4. Since I have to have the front end repaired before turning the leased car back, plan to drop it off at my mechanic next week so he can work on it over the slow holiday period. He has all the parts already, has to paint the bumper black and then install it, the new headlamp and fix the quarterpanel as the part was not available. Will drive the ICE wagon as needed but generally tend to hibernate over the holidays.

5. Last, it strangely occurred to me last week that with a 100 mile ish range compared to say 400 miles with my ICE wagon, I was driving figuratively with a quarter of the accustomed range. I have long since gotten over range anxiety as I have been conditioned to charge when the battery drops to 35% in the winter and 20% in the summer.

Happy holidays to all whether like me you are in the Northeast/Canada/UK/Midwest or one of the lucky ones in the Southeast or West. There is at least one member in Hawaii and the Caribbean.