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Charging schedule driving me nuts

9.7K views 43 replies 9 participants last post by  LincolnGreen  
#1 ·
Like many people I have cheaper electricity at night and want to charge the car during those hours. The car, on the other hand, has other ideas.
I set the car to charge in the preferred hours, I set the charge limit just 12% higher than it's current SOC, and I set a departure time for 4 days time.
Now, it should charge the 12% in one night so I would expect the car to start to charge as soon as it is plugged in, pause after a few minutes (once it has done some calculations) and then charge in my preferred slot.
It has only done this once. All of the other times it has not paused.
Anyone else having issues?
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#2 ·
Like many people I have cheaper electricity at night and want to charge the car during those hours. The car, on the other hand, has other ideas.
I set the car to charge in the preferred hours, I set the charge limit just 12% higher than it's current SOC, and I set a departure time for 4 days time.
Now, it should charge the 12% in one night so I would expect the car to start to charge as soon as it is plugged in, pause after a few minutes (once it has done some calculations) and then charge in my preferred slot.
It has only done this once. All of the other times it has not paused.
Anyone else having issues? View attachment 32825 View attachment 32826
If you go in the car to the vehicle apps/charging mode you can set a time slot. It may ask you to set a departure time first. Then you can set the start and stop times.
Then check charging target and ac limit to levels that work for you.

I set the lowest current that will meet the soc in the time slot.
 
#3 ·
If you go in the car to the vehicle apps/charging mode you can set a time slot. It may ask you to set a departure time first. Then you can set the start and stop times.
Then check charging target and ac limit to levels that work for you.

I set the lowest current that will meet the soc in the time slot.
Yep. Done all of that.
 
#5 ·
I have tried that but the thing I am trying to achieve is where the car charges over a number of nights to my desired soc. So, let's say I am at 20% and want to get to 80% but only charge at night then setting as you suggest won't work. The car will calculate that I don't have enough time to charge to 80% in the six night hours and will start immediately. By telling it I am not leaving until Wednesday, it should know that it has enough nights to achieve this. Thereby sticking with my preferred hours.
 
#9 ·
This seems a bit confusing. Just get rid of departure time, set your time limits and set a low amperage limit. That way it will trickle every night with no real target in mind.

Is there any reason you only want to charge 12% per night?
 
#12 ·
If I understand correctly, you are only using a wall outlet "a la level 1", so the car will only charge about 1% every hour? If thats so, if you set charging windows without departure time, (ex. 9pm to 7am or w.e. your cheaper rate is), the car should only charge over that time period. I have a Lv 2 charger at home and plug it in every day after getting home from the gym or work and it only charges between 7pm and 7am for me, as that is the time slot I have selected in the BMW app, up to my set limit of 80%.
 
#14 ·
You are totally right, the car is ignoring your departure if you set a departure time. The departure time and date is only working for preconditioning the car, not charging to departure.
My understanding is the car will use the departure time to calculate if there's enough time (and amperage) to charge to the determined %. If not, it will start charging when it feels it's necessary and ignore the set charging window. If the OP is using a L1 charger, I'm not surprised all setting are being ignored.
 
#17 ·
I am surprised your not surprised ;).
15% per night is enough in my example to use my preferred hours if I set the departure time for 5 days time. Makes perfect sense to me and they provide the option in the menu.
If I drive the car before my stated departure time and then plug it back in again then I would expect the car to do a further check on whether it can hit my target by the stated departure time by using preferred hours. If it can't then, fair enough, charge outside the preferred hours.
Can't be that difficult can it?
 
#20 ·
I've had one occasion where I was charging from <20% to 100% and the car started changing prior to the pre-set window. Annoyingly, it finished charging with time to spare, so could have fit into the window, but at least it did what I expected and started charging early to be sure full charge was reached prior to my set departure time.
 
#34 ·
Trickle charging an EV at a very low rate has often been proven to waste appreciable energy, because every minute the car's onboard charger is active it's burning up hundreds of watts of waste heat. For this reason, 110V charging (or extremely low current 220V) is usually a false economy. Folks try to save money with an emergency or portable EVSE but if they carefully tested the losses, they'd be better off with a competent wall charger or in this case not throttling the provided BMW EVSE with an artificially low charge rate. Worst case, wasted energy could be 30-40% of total charge energy, depending on the efficiency of the onboard charger on the i4.
 
#37 ·
I don't know if that's applicable to the i4, but sure, two phases is better than one, and three phases, like I have, is even better. I have 11kW 3 phase box, in fact just today upgraded to a new one, which is a smart charger and actually takes low tariff into account also, and I can actually set a departure hour, low tariff time slot and how many kWh I want to have pumped in minimum so that it's enough for my departure. It means that if my low tariff time is long enough then it will use that time slot, if not then it will start charging before the start of the time slot so that the battery is charged with my preset desired kWh to my departure time.
 
#39 ·
It's called Zaptec Go. I don't know if you can find it in Canada, but it is very small and has a very nice web and phone / tablet app interface. The installation was easy, but it was done by an electrician since it's a law in Sweden. It means also that the government is paying 50% of the costs. I got also load balancing installed, so I can always charge at maximum available current. The hose has the priority, so if I need to heat the house or cook, wash and vacuum clean a cold winter day then the car will only get whats left and available during the charging. This, and the smart charging are features I wanted and could not get to my previous charger, plus the previous one had a fixed cable which needed to be changed and since it's the second time in five years, I did not want to pay for a new cable. The new box has Type 2 socket, so it needs a Type 2 cable also, if we want we can use our own, but I decided to get a 7.5m long cable with the box also so that we can keep our Type 2 cables in our cars and we can reach a third visitor car, if we get visitors who might need charging.

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The box is very small when the cable is not plugged in, in my opinion it looks good, and you can get with covers in several different colours. Up to three boxes can be connected daisy chained on the same mains, and they will manage the power internally so you never overload your mains. I don't plan any extension, but it's good to have that feature if I change my mind. I hope it will work well, but it has a good reputation in Sweden. The box is made in Norway.
 
#44 ·
Like many people I have cheaper electricity at night and want to charge the car during those hours. The car, on the other hand, has other ideas.
I set the car to charge in the preferred hours, I set the charge limit just 12% higher than it's current SOC, and I set a departure time for 4 days time.
Now, it should charge the 12% in one night so I would expect the car to start to charge as soon as it is plugged in, pause after a few minutes (once it has done some calculations) and then charge in my preferred slot.
It has only done this once. All of the other times it has not paused.
Anyone else having issues? View attachment 32825 View attachment 32826
Every time, although have only recently got the car. I have to stop charge on the app.