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Discussion Starter #1
Hi,
I'm sure there are answers to these question but I can't find them on the forum.
I want to charge only with off-peak electric (even of it doesn't get 100% charge), and manual preheat the car from battery. My off peak rate is 00:30 to 04:30.
Is this possible?
Also- how does the i3 work out when to start charging if the departure time is set?
The car seems to connect to the power briefly when you initially connect it- is it at this point it works out the power available (16 or 32amps) and then works backwards from the departure time to see when the start time for charging should be?
 

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I recently tested my i3 (for the first time in 3 years from new) to check if I could use off peak charging as I am considering getting off peak rate, I just set the time I wanted it to charge 00:30 until 04:30 and it worked perfectly, but you do have to put a departure time in as well, now I am not sure why you cannot do one or both separately but that seems to be the way it works.
I did notice after about four days it came up with a message saying the departure time had not been used.....I just ignored the message and the system continued to charge off peak.
 

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You're right that the i3 will charge briefly to check the available power supply.

If a departure time is set, with the tariff box checked, the car should start charging within the specified hours, time to start such that it will complete charging near the departure time.

If no departure time is set, it should still complete charging during the first opportunity.

The caveat is that if the i3 determines it can't complete charging prior to the programmed departure time, it will begin charging outside of the tariff slot window.
 

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Discussion Starter #4
I can't set off peak charging without entering a departure time.
I think the Off-Peak Charging times only work if the i3 thinks it can charge to 100% within that time period. I've got a fault on my Rolec charger (hopefully sorted soon), so its only charging at 16amps. I set the departure time for 4:30am, but the charging starts before 00:30.
Hopefully once the charger is fixed the car will be able to fully charge in 4 hours.
 

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Mine is charged using the granny charger so when more than 75% depleted never gets a full charge during off peak, but it still charges.
I set the charging time at 00:30 until 04:30 and set the departure time at 09:00 and it all worked fine, apart from the message after a few days telling me I hadn’t departed at the allocated time, must be the German precision doesn’t like British “couldn’t give a monkeys“ attitude :D
 

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...apart from the message after a few days telling me I hadn’t departed at the allocated time...
I've only done that while not plugged in. Once it misses two or three consecutive departure times, I see the same message as you, but the car also informs me that it will stop executing preconditioning so not to run down my battery. It would make more sense to send that message to my phone, so I can make adjustments to my departure times.
 

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I set the charging time at 00:30 until 04:30 and set the departure time at 09:00 and it all worked fine, apart from the message after a few days telling me I hadn’t departed at the allocated time, must be the German precision doesn’t like British “couldn’t give a monkeys“ attitude :D
Don't forget that you are spending money to precondition the car at 9am - probably 2kWh worth as shown below at 6am.

My i3 starting charging at 1am and precon at 6am. Zappi charger:

128049
 

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Some good advice here. If I just want to use off peak charging, then I just set a departure date a few days ahead. Preconditioning - are we talking cabin or battery, or both?
 

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Discussion Starter #9 (Edited)
In the Connected Drive app preconditioning is optional.
So I presume if you don't tick it the departure time is used purely to work out charge start time to get to 100%.

Once my charger is repaired I might reinstate the smart relay board which would allow me to disconnect the Control Pilot line to the car after 4:30am, this should stop charging, and I'm hoping the car will then preheat off batteries if I tick the option.
 

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Don't forget that you are spending money to precondition the car at 9am - probably 2kWh worth as shown below at 6am.

My i3 starting charging at 1am and precon at 6am. Zappi charger:

View attachment 128049
Yes indeed, but I was just testing the system, if and when we get off peak I shall set the departure time to the end of charging so as to combine the two, I realise it will still be using more leccy but it’s the only way I can find to set charging time, no option for setting off peak charging without setting the departure/pre conditioning time I can find.
 

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Discussion Starter #11
There's a write up here BMW i3: How Preconditioning Works about preconditioning the i3.
The car can precondition the interior (heat or cool?), and/or the batteries in order to maximise range.
If I understand it correctly- the departure time sets the battery preconditioning. The 'Preconditioning' toggle switch in the app is for the interior.
From the web link above the guy says the i3 has to be plugged in for battery preconditioning.
So........
If I want to charge the car off peak only i need to-
  1. Set the 'Departure Time' for some time after the Tariff Time Slot
  2. Set the Tariff Time Slot to 00:30 to 04:30
  3. Install my smart relay to cut the Pilot Signal after 04:30. This should stop any further charging, but also stops battery preconditioning.
Hopefully then if I want to set the 'Preconditioning in the app' the car interior will warm/cool just off the battery.
I'll do some testing at the end of next week.
 

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As I said in an earlier post, if I set a departure day of, say, Sunday with 0030 to 0430 off peak at a 25% SoC, then I guarantee that tonight the car will charge for just 4 hours and stop whatever the SOC. The following night it will charge for another 4 hours/or until it reaches 100% SOC.

If I set at departure time of 0600 hrs tomorrow, the car will charge off peak for 4 hours and to 100% SOC in peak. It may well achieve 100% SOC before 0600 hours. If you set battery preconditioning, the BMS will determine when preconditioning starts which, in turn, is dependent on the temperature of the battery. Cabin conditioning usually starts at about 30 minutes before departure.

PS When setting a departure time with preconditioning, the set time must be at least 3 hours in advance.

PPS You do not need a departure time to condition the cabin via the App. It is though a bit hit and miss and it requires both your phone and the car to be contact with BMW’s server.
 

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As I said in an earlier post, if I set a departure day of, say, Sunday with 0030 to 0430 off peak at a 25% SoC, then I guarantee that tonight the car will charge for just 4 hours and stop whatever the SOC. The following night it will charge for another 4 hours/or until it reaches 100% SOC.

If I set at departure time of 0600 hrs tomorrow, the car will charge off peak for 4 hours and to 100% SOC in peak. It may well achieve 100% SOC before 0600 hours. If you set battery preconditioning, the BMS will determine when preconditioning starts which, in turn, is dependent on the temperature of the battery. Cabin conditioning usually starts at about 30 minutes before departure.

PS When setting a departure time with preconditioning, the set time must be at least 3 hours in advance.

PPS You do not need a departure time to condition the cabin via the App. It is though a bit hit and miss and it requires both your phone and the car to be contact with BMW’s server.
Aha that’s interesting, I had not noticed (having never used the facility in anger) that you could pick a day as departure time, that’s better.....now I know I can programme in the off peak all week without the system trying to precondition every day saving that leccy.

Excellent, thanks for pointing that out, no one else has ever mentioned that as I recall.
 

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Some good advice here. If I just want to use off peak charging, then I just set a departure date a few days ahead. Preconditioning - are we talking cabin or battery, or both?
^^This. Select the day of the week when you don't charge the car or differently, when you want the car to be charged to 100%. The rest of the week it will follow the off peak charging schedule with "german" accuracy.
 

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And remember, even if you don't set up the recurring departure schedule (or even if you do), you can arrange a one-time-only departure time on your dashboard screen when exiting the car. (Maybe that's what you're referring to; seems like a buried / hidden feature to me.)


I can't set off peak charging without entering a departure time.
.
Oh, I see what you're saying! The tariff time slot option completely disappears.

Huh, I must have had a departure time set, or maybe my phone app wasn't synced with the in-car settings.
 

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Huh, I must have had a departure time set, or maybe my phone app wasn't synced with the in-car settings.
In my experience, the i3 can get confused when the App is used unless you can guarantee that both your phone and the car have a good connection to BMW’s servers.
 

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I almost always have good connectivity, but I notice that if I change settings by way of the in-car display, the phone app doesn't always reflect those changes right away.

If I make many schedule changes, get out, and then make a minor change via the phone, there's a chance I might overwrite everything I had just done from inside the car.
 

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I almost always have good connectivity, but I notice that if I change settings by way of the in-car display, the phone app doesn't always reflect those changes right away.

If I make many schedule changes, get out, and then make a minor change via the phone, there's a chance I might overwrite everything I had just done from inside the car.

I have occasionally tried to condition the cabin using my phone which appeared to work as intended (ie, a SEND indication in the App) only yo get to the car to find that the message had not been received. Not unique to the i3 I should add.
 

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Discussion Starter #20
OK. Charger has been repaired so it charges at 7kw. I installed my internet connected charger relay mod board which basically allows me to make/break the control pilot wire.
I've set the i3 to immediate charge, and the relay activates at 00:30am and stops at 04:30am (in line with the Octopus GO tariff). 7am cabin preheating now works purely off the battery. No battery conditioning- but I don't need it for the distances I travel.
FYI- the dashboard shows when I've insert the charging cable, it show a cable with a clock symbol. The i3 must be detecting the Proximity resistor in the charging cable, but thinks the cable is not plugged into a EVSE because there is no Control Pilot signal.

I've not worked out any electric cost savings- they might be minimal. Maybe £70 a year if you use cabin preconditioning everyday.
That might be offset by the batteries not being preconditioned and working less efficiently. Who knows????
 
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