It will come from the mains.

 

Itll be the battery - mains will only be connected during a schedule.. and the car will refuse the "charge" if at 100% too.
The car will always use its battery anyway, as the mains (and a wall charger only ever connects mains to the car) will only connect to the cars charger proper.

 

I very much believe you are mistaken. As long as the charger is connected and active, power for preheating will be drawn from the mains.

It's easily tested: charge the car to 80% and end the schedule before preheating starts. Set preheating to warm up the car to 22 degrees and when leaving, check if the battery is still at 80%. When it's really cold like e.g. 5 degrees, preheating to 22 degrees will take at least 1 kWh, which is almost 1.5% of battery. So the battery would be at 79 or 78% if power was drawn from the battery.

 

See this PDF, p.H9 (but that’s all it says)..

https://www.hyundaicanada.com/-/med...feature/ownerssection/manuals/english/2021/kona-ev/os-ev-can-e-system-intro.pdf

“Pre-schedule heating
If the target temperature (1) is set with the cable connected, the cabin temperature will be adjusted to the target temperature at departure time (without loss of high-voltage battery charging level). In cold weather, pre- schedule heating helps enhance electric vehicle performance by heat- ing the vehicle in advance.”

 

Not Kona specific, but in general the components in the car will either be 12v fed from the HV battery via the DC-DC convertor, or 400v and fed directly from the HV battery ( this would include things like the air con compressor which in an an ICE would be driven via a belt ). Pre-con heating will use power from the HV battery not 240V AC, but if charging at the same time at 7kw this will be replaced as fast as it is being used.

However, if the car was charged overnight on a cheap tariff, you might be better using the cheap electricity stored in the battery to run the pre-con rather than paying for peak time - unless you need the full 100% range.

 

Not Kona specific, but in general the components in the car will either be 12v fed from the HV battery via the DC-DC convertor, or 400v and fed directly from the HV battery ( this would include things like the air con compressor which in an an ICE would be driven via a belt ). Pre-con heating will use power from the HV battery not 240V AC, but if charging at the same time at 7kw this will be replaced as fast as it is being used.

You don't have to be charging. What happens is that it will draw a high current temporarily but then it tapers off to consume from the grid what it uses for the heater. What likely happens is that it measures the current that the battery has to put out and it compensates it by letting the same amount of current into the battery. The battery charge percentage will therefore not decrease not increase. Net result is that the power that is used to heat or cool the cabin is drawn from the grid.

There's a vid that explains it all here: