I3 not following delayed off-peak charging

[Jawahar]

Hello all - I’ve set my I3 (2020 reg) to charge between 00:30 and 04:30 to take advantage of cheap electricity. This has worked well for the last month I’ve had the car.
However, this evening when I plugged in the car (70% charge remaining), the car started charging immediately even though both the EV and the app are set to charge off-peak. I’ve tried turning this feature off and on both on App and EV with no success. Reading up on previous threads on this topic here don’t suggest a solution/diagnosis. Any help/pointers greatly appreciated.

 

[eNate]

You sound well versed in this already, so these may be obvious suggestions you've already considered:

- is it possible you mistook the initial handshake for "charging?" This is the brief period after you plug the car in and it begins a short cycle of charging to assess what level of charge is available.

- if there isn't enough time to charge to 100% before the next scheduled departure time, iDrive will ignore tariff time slots and begin charging immediately. You didn't mention what rate you're charging at.

 

[Jawahar]

Ah yes. I thought it would turn off as always in a minute or so, but it kept on charging at 4.3KW (on a 7KW wall mounted charger) for the next 30 minutes before I switched it off (in which time it got from 70% to 73%). Interestingly the app continued to show “Charging Paused” and Off-Peak schedule through it all.

The end time to full charge was 3 hours away so that would have been enough time to charge off-peak.

I will try again tomorrow and then fix up with BMW to check it over. Was just wondering if there was an obvious fix/reset I could do to save the hassle.

 

[jadnashuanh]

In theory, the car is supposed to ignore your charging window in a few situations:
- if the battery state is quite low to prevent cold from damaging them...it's supposed to charge some, than pause
- if there's a departure time set and it determines it can't fully charge by then
- if the batteries are quite hot, it may not actually start charging, but go full cooling mode which does use energy from the EVSE
- if the charging window is not large enough to fully charge the batteries

It seems, the only way to ensure the vehicle can only charge during a specific window is to either have an EVSE that can do it, or use some smart power control to turn the power on/off to the EVSE.

 

[alohart]

The i3's delayed charging software implementation seems to have been buggy for years, or we just don't understand all the situations in which it ignores the delayed charging start time.

 

[Jawahar]

Update: The problems seem to have miraculously solved itself this evening. I did absolutely nothing to the car since my previous update.
Strange!

 

[JonK]

Yup - the software on this feature is indeed buggy. My 68 reg will sometimes work perfectly toggling between immediate charge or a timed slot and other times won’t take any notice of a timed slot and just charge immediately.

To counteract this, I have organised my home charging point to commence charging at 00:30 when things go cheap, and all is therefore well.

If possible, I’d suggest you do the same - programme your home charge point with the hours you want and leave the car in ‘charge immediately’ mode.

 

[Beardsley]

My 2015 i3 worked fine for off peak charging for years. Sadly it does not work now. I am not sure what happened.

I have a departure time set for 7:50 am daily and Off-Peak Timer set from 11:00 pm to 7:00 am. Also, low cost charging set. There are a little 1 2 with circles around them. I assume that stands for level 1 & 2 charging.

Every time I plug in the level 2 charger it starts charging and displays the departure time.

The dealer plugged the charger in at their work station and it started charging right away (which is the problem). They said everything looks fine. Obviously they don't understand what low cost or off-peak charging means. So I don't have much confidence in them.

Off peak time is 8 hours so there is plenty of time to fully charge my 20 kWhr battery. Should I try a different departure time?

Any help would be appreciated.

Other than that the car drives great. I will be sad to see sales of the i3 go away. Thinking of a new Galvanic Gold i3s.

 

[frictioncircle]

by Beardsley » Wed Apr 07, 2021 4:40 pm

Other than that the car drives great. I will be sad to see sales of the i3 go away. Thinking of a new Galvanic Gold i3s.

Galvanic Gold is the best i3 color since Solar Orange!

Regarding forcing the i3 to low-cost charge between specific hours, I've found that the best way to do it (like others have suggested) is to specify the valid charging period at the EVSE, not in the i3. Doing this allows you to absolutely control when your i3 will charge from your EVSE.

Relying on a "departure time" + "low-cost charging" in iDrive empowers the i3 to consider the battery state + when you plan to start driving, and (in my experience) it overestimates the time needed to reach a full battery. Because of this, the car tends to disregard the "low-cost" times that have been specified in iDrive and will start charging sooner than the "low-cost" time that you've specified.

 

[Beardsley]

Thanks for the info.

The next level 2 charger I buy will definitly be a smart charger.

I am thinking of modifing my current Bosch charger by putting a timer on the on/off switch which I can set to the low cost time from the power company.

I have to say the level of compitance I see about electric cars at the dealership has me a little worried about BMWs electric car future.

 

[Neil]

When I purchased my i3 Rex in 2014 and expected to use low cost charging, I was in for a real surprise. Long story short, it was not reliable. I went back and forth with the dealer about this, sending in reports of the failures over periods of weeks but finally gave up as no help was forthcoming. I ended up installing a water heater timer on my EVSE (a basic Clipper Creek model) and set the car to immediate charging which solved the problem. A smarter EVSE would have eliminated the need for the timer but I had expected low cost charging to work. Silly me! :lol:

 

[Beardsley]

Sounds like a really good idea. I just ordered a "Programmable Timer Switch Time Relay Digital LCD" from amazon for $12 to wire to the on/off switch of my Bosch Power Max Level2 charger. I will post my results.

I love my i3 but I am lossing my confidance in BMWs electrification.

 

[alohart]

I just ordered a "Programmable Timer Switch Time Relay Digital LCD" from amazon for $12 to wire to the on/off switch of my Bosch Power Max Level2 charger.

How many amps is your Bosch Power Max Level 2 EVSE providing and what it the amperage rating for your Programmable Timer Switch Time Relay Digital LCD? It looks like most timer switches in the $12 price range are limited to only 16 A whereas the i3 can charge at up to 30 A.

 

[Beardsley]

I am switching the on/off switch not the main power. The relay is rated at 30A which seems high, but the on/off switch is very low power just to enable the charger.

Thanks

 

[alohart]

I am switching the on/off switch not the main power. The relay is rated at 30A which seems high, but the on/off switch is very low power just to enable the charger.

An on-off switch on the low-power side of the relay is a nice feature that few EVSE's seem to have. However, to access the low-power side, are you splicing into the internal EVSE wiring? Otherwise, all EVSE power usually comes through a single power cable that carries high power.