Speculating on how timed pre-warming works

[SanSerif]

I've been experimenting with setting a departure time and allowing the car to pre-heat in the morning. A couple of things I've noticed:

The car seems to need to be charging the battery in order to pre-heat. I had a peek at progress 30 minutes before departure time and nothing had started yet. Also, the charge socket was red (which alarmed me) and when I turned the car on I got a "High Voltage Battery Not Fully Charged" warning (that alarmed me more). But the battery was *almost* full. So I watched what happened next. About 10 minutes before departure time it started pre-heating and started charging. The red charge socket changed to the more familiar flashing blue.

Secondly, the car seems to start pre-heating very close to the departure time. Maybe 10 minutes or so. I'd have thought it would start much earlier - drawing power straight from the mains to soak the car with heat.

It also seems to be quite poor at predicting when it needs to start warming. I think (I'm still new to this and the various messages and statuses are a little confused in my mind and memory!) I've had a couple of mornings when the predicted "full" time has been later than the pre-programmed departure time. It could be, though, that my intrusive peering in and unlocking etc has upset the car's carefully laid plans.

I'll continue to experiment and will update as I observe more.

 

[noakey]

Hmmm... We will soon compute the logic of charged vs preheat saga from everyone's trials and experiments. .. let'scall Iit cloud knowledge funding... keep posting. Neil.

 

[Simon]

Same with me. At exactly 9 minutes before departure the car draws current from the charge wall box.
When you set a departure time, WITHOUT pre conditioning of the interior, it seems that nothing happens at all.

There is also a problem in my i3 related to the charging. I cannot get the full 32 Amps. It will go to the workshop in a few days. When it's fixed i will observe some more pre heating (battery) and pre conditioning the interior. I suspect this might have the same cause as the pre-heat.

Only the first few days with the car i noticed it was working half an hour before departure. But the charger responded very erratic, switching on and off for 20 minutes.

 

[CompuMagic]

I cannot get the full 32 Amps.

Just curious how you are determining that you can't get a full 32 amps? I do not have the i3 yet but is on order. Thanks

 

[Simon]

I can monitor the power taken from the house with a small device. The difference in consumed power (the whole house) between the i3 being home and connected to the wall outlet charger, or being disconnected is never more than 3.7 kW; divided bij 220 volts is 16A.
But i also measured the actual current using a current-clamp tool (to be sure) and it was also 16 amps.

 

[Atommad]

I cannot get the full 32 Amps.

Just curious how you are determining that you can't get a full 32 amps? I do not have the i3 yet but is on order. Thanks

If you are in the UK you will get a smart meter when you get the charger installed. This will have a digital display which will show you the rate of charge, which should be around 7.4 kW at 32A. The meter will also show the total energy used (kWh).

 

[CompuMagic]

I cannot get the full 32 Amps.

Just curious how you are determining that you can't get a full 32 amps? I do not have the i3 yet but is on order. Thanks

If you are in the UK you will get a smart meter when you get the charger installed. This will have a digital display which will show you the rate of charge, which should be around 7.4 kW at 32A. The meter will also show the total energy used (kWh).

Thanks. I am in the USA. I will investigate getting a meter for my self. That sounds useful for sure. I just bought a 9.6kw charge from Leviton, which was originally made for the Toyota RAV4 EV, and I wanted something that would be useful in the future if I get a vehicle later on that can draw more power.