Range Extender Tips & Tricks

[JeffRay]

Hi, so my newly leased 2017 has the range extender, my old 2014 did not. Not quite sure how it works.

1. I know, push the button on the dash before charging and wait for green LED to light. Got it.

2. What is the deal with the Pre-determined Departure time, which is mentioned in the manual in the Range Extender part. Yes, I pulled out the manual!!

3. With the Range Extender on, does the Pre-determined Departure time affect the rate of charge? My theory of why I am getting a crappy rate of charge is that without selecting a departure time, it is not charging at the full rate. Does that make any sense?

4. Not sure if selecting Range Extender affects the info on Apps. Does 100% mean 100% or 120%? Time to full charge is to 100% or 120%?

Any advice appreciated from those who have figured this out. Thanks.

 

[in2insight]

JeffRay,

I use the Range + from time to time, and do what you outlined but have not entered anything in Departure Time.
My charger has an app, and in it I have set the ideal charging times and it charges based on that.
When done, it shows as being charged 100% and the only difference is in the car display, which now shows 90 or so miles vs. the 80 or so when charging without the range +.

Hope this helps.

 

[pva]

Hi,

3. With the Range Extender on, does the Pre-determined Departure time affect the rate of charge? My theory of why I am getting a crappy rate of charge is that without selecting a departure time, it is not charging at the full rate. Does that make any sense?

4. Not sure if selecting Range Extender affects the info on Apps. Does 100% mean 100% or 120%? Time to full charge is to 100% or 120%?

3. In my experience Range+ and departure time does not affect on charge rate. I have been following this a couple of week for now because outside temperatures has been between -25C - 10C and I am using the function in every charge. Every time charging starts with a bit lower rate, but after a while it rises up to max 11kW (with my 3-phase 230VAC charger). However there is some relation between the departure time and outside temperature. More cold and heating begins earlier. In -20C the car starts battery heating about a one hour before the departure time (can hear bubling noise under hood) and indoor heating starts about 20min before departure. In case of -10C heating times are shorter.

4. 100% in dash display means actually 120%. With Range+ I can drive about 10km before battery level drops from 100% to 99%. Without R+ battery level drops to 99% right after moving the car.

 

[JeffRay]

Brought car into dealer so they can figure out how to charge at their max 6.6 KwH rate with range extender on and off and give me specific instructions. Will post if they shed any new light beyond the helpful posts so far.

Enjoy the ride!

 

[JeffRay]

Picked up car and it was clear that the technician had not even looked at car as I was asked if I could leave it for a longer stretch. As it is my get to work car, I will do that during spring break.

My Service Advisor does not know what to do so I kept it simple. Show me how to charge at 6.6 kWh rate which it is supposed to. I also showed him the app which showed it only doing 4.4 kWh. Next I suggested as nicely as I could that perhaps the tech needed to question Germany as I could not be the only one with this problem.

Tomorrow, I am going to try charging it without the range extender on and no pre-determined departure time and see what happens.

 

[GlennD]

I only use the range extender when I go to the TRW Amateur Radio Swap Meet that is 39 miles away. I likely could make it but the extra gives me a warm fuzzy feeling.

 

[JeffRay]

I am starting to think the range extender option changes the procedure to charge at fastest possible rate.

In my 2014 wo range plus, I just plugged in and voila, either 1.2 kWh on 110 or 6.6 kWh on 220 charger. Simple.

With my 2017 w range plus, when I charged without range plus activated, same as with 2014.

With my 2017 w range plus on, the charging rate was all over the place but consistently below max rate. I have started to set departure times and I have gotten close to the max rate today. Hm.

 

[in2insight]

I used Range + last night, and every so often, the kWh went from max to zero and right back up again, sharply. On the last few minutes it went from max to zero 6 and to off.
Of course, with the rain and such, this could be due to power fluctuations, as looking back at history, this is not the pattern on the other few times I have used range +.

 

[GlennD]

My car charges at 40A at 240VAC all the time. The range extender makes no difference.

 

[JeffRay]

So my guess is selecting the range extender and a departure time allows the car to choose the charging rate. While my math skills were never that good, it appears so to me. Example: It is 9 am now and I set 1 pm as my departure time. The car is 43% charged. As a result, the EVAccess app is showing the car charging at a 5.7 kWh rate to achieve 120% charge. This is instead of the available 6.6 kWh rate that this particular charger used to charge my 2014 which did not have the range extender option.

If correct, my guess is that a MB engineer programmed this to spare the battery from faster charges. Of course, in a commercial lot, they like to unplug the car for the next favorite customer so I have to do mental math to select a time that allows for a high charge rate in the shortest amount of time.

Live and learning with my new 2017 B250e.

 

[GlennD]

6K is what you get from a commercial 30A 208VAC EVSE. Most commercial EVSE's run off of a wye that supplies 120VAC and 208VAC unlike iif t was powered from a delta. In addition most EVSE's are 30A max not 40A.

208 vs 240V is a 25% hit already then add the 10A loss for a 30A EVSE. For all but Tesla powered cars that is not a problem My eGolf charged at 30A from my 40A EVSE.

The public EVSE's at both Long Beach Mercedes and Mercedes of Anahein run off of 208VAC and they are 30A max.

 

[bcurious]

My car charges at 40A at 240VAC all the time. The range extender makes no difference.

I'm glad to hear this.
If we get into another B-class, it will certainly have the range charge feature and the electrically defrosted windscreen.
Charging at home, I'll be able to supply it with 40A and will desire to do so when we're charging two EVs per night.

 

[JeffRay]

bcurious,

Having the range plus on my 2017 vs non on my 2014 has gotten me through this winter on a diet of once a week full charge with top ups at one of my work locations a couple times a week. This is versus twice a week with my 2014. There are other factors of course, temperatures have cooperated.

I am not getting into an argument with Mr. GlennD but at least in my car, the rate of sucking juice into my 2017 with range plus activated varies and the only way I can get full speed intake is either by deselecting range plus or doing a quick calculation in my head and putting in a predetermined departure time that forces the car to suck juice at fastest possible rate.

With a home charger like GlennD has, it sounds like the rate is selected on the box, not the car. At commercial stations or outlets where I charge, it seems as if the car decides how fast it wants to suck juice.

Sorry for the use of slang for those offended.

 

[GlennD]

Assuming that there is enough current available the car will charge at the full current (40A). If less is available then the car will match the available current. Phil Childs has a box to step up the 208VAC. Other than that nothing can be done about the 208VAC. The box has a transformer and you plug the EVSE cable into the box and in his case the box's Ji772 cable into his RAV4 EV. That gains him 25%. The pilot runs straight through but the L wires are stepped up.

It is unfortunate that commercial power is 208VAC vs home power at 240VAC . That places most commercial EVSE's at a disadvantage compared to home L2 EVSE's.

 

[pva]

My car charges at 40A at 240VAC all the time. The range extender makes no difference.

Same with my 2015 model. Full rate in with or without R+ and/or predefined departure time. 3ph-16A-400VAC-11kW. Only rate resisting factor seems to be ambient temperature. Cold car gives lower rate and warm car right after driving enables full rate.

 

[JeffRay]

Thanks PVA. In my new 2017 it seems to matter with R+ what is set for departure time. Hm.

 

[GlennD]

Well Jeff believe what you want. The car's charger does not care it the range button is pushed.

The only thing affecting charge current is the EVSE and how it is wired. Both of the dealers I have worked with have 30A EVSE's hooked up to 208VAC. At 30A and 208VAC the max is just over 6000 watts. If a 40A EVSE is available then at 208VAC then it will charge at 40A X 208VAC or 8320W. 10K requires 240V! Unlike my eGolf or my Leaf's the power factor is not 1, It is a few percentage off, Volts X Amps is not quite accurate. True power is Volts X Amps X the power factor.

 

[GlennD]

An extreme case of power factor is a HP power supply I own. At full load it draws 3750 Volt amps or 2200W. Switching supplies are known for bad power factors. Most cars are compensated at the rated charge level. A lab test supply obviously is not compensated.

I tested the supply when I received it but since it requires 240VAC it just sits. To use it I would have to run a 20A 240VAC circuit to my workshop. Unless I really need high power that is not going to happen.

 

[JeffRay]

GlennD,

Yes, agree believe what we want.

In my case, testing at same commercial charging stations would indicate for my 2017 selecting R+ does matter. At 3 different locations, wo R+, I get the same draw, 1.2 kWh or 6.6 kWh. With R+ selected, it varies based on Predetermined Departure time drawing at rate needed to achieve 100%.

So in my case, for my car, having tested, I believe it matters. Not having a home charger which can override, I make no warranties.

 

[evnewbie]

My EVSE controls the max power that can be supplied (~10KW in my case) and the B-ED charger controls the charging power levels (up to the EVSE max) based various car conditions and settings (e.g. battery temp, current battery level, departure time, range extender on/off, etc.) that are not visible to the EVSE. I have a 2015 B-ED with range extender and 40A/240V home charging (JuiceBox EVSE) and my observation when range extender charging is on the charger in B-ED will charge using max power (~10KW) until the normal non-extended battery level is reached then taper off power down to ~3.5KW over the last ~30 minutes of charging.