Pre heating question

[Rolfe]

Not necessarily ... until I had the recent updates applied to my car then I couldn't ever preheat whilst plugged in and not charging. The charge point was in the Waiting state waiting for the car to request a charge, and the car wouldn't accept the remote HVAC or battery heating controls from the app. Now it all works as expected ... nothing to do with being on a TOD tariff or not. (I'm not)

So does the power for that come from the mains and not from the battery now? If I'm starting on a long trip in winter I'd prefer not to lose 2% (or more I suppose if I pre-heat the battery too) before I even start.

 

[siteguru]

I've not tested that yet. My expectation is that it will come initially from the battery and then the car will request additional charge from the wall box. (Or maybe I'll have to manually request to start charging - I don't know).

 

[Rolfe]

Hmm, that could be a problem with a granny charger. If it takes the power from the battery, then it is not going to have time to replenish it from the mains before you drive off. Even with a wall charger, you're going to notice it. You want to do the pre-heat immediately before you use the car.

 

[siteguru]

I'm currently running a test ... I plugged the car in again (it's already at 100% and balanced). I turned on battery heating and also HVAC preheating. The Wallbox app shows 7.1kW being drawn from it but the iSmart app shows the car is charging at varying rates from 0.05kW to 2.28kW. So the difference in charge is going towards the HVAC and battery heating.

I'll leave it running until HVAC stops and see what the rate changes are.

Update: HVAC has stopped and Wallbox now shows 3.6kW draw, with balance charge levels going into the battery. So battery heating seems to account for about 3.5kW of draw.

Restarting HVAC for a second time increases the battery charge rate to between 0.22kW and 2kW, so it seems that HVAC takes its power from the battery thus the charging compensates for it.

Further update: 2 cycles of HVAC complete but battery heating still running. Balance charge levels going into the battery but the Wallbox is still showing about 3.6kW being pulled from it.

Final update: battery heating stopped after about 45 minutes and the car stopped the Wallbox.

 

[Rolfe]

So did the battery stay at 100% all the time this was happening?

 

[mg4mc]

So did the battery stay at 100% all the time this was happening?

Mine does, but the charger was outputting 7kW to compensate - though not continuous, it seemed to let the battery discharge a bit then charge it again. But I haven't sat and watched it continuously.

That was with battery heating running as well.

 

[siteguru]

It seemed to - certainly the app was reporting it at 100% all the time. Range dropped when the HVAC was active (as it normally does when you get in the car with AC on) but the SoC remained at 100%.

My experiment suggests that using a granny lead may still incur some battery usage.

 

[Rolfe]

Well, I'm not going to get R33 before the new year, so it's a bit academic at the moment!

 

[Martinonline]

I charged my Trophy, not on updates software, overnight to 100% on the granny charger and let it balance. Later I tried to pre-heat the car, it failed. I then tried to restart charging and I got a 'please plug in the charger' message. I unplugged the 13amp plug, counted to 10, and re-inserted the plug hoping to fool the car that it had just been given power via the granny charger. It did not work, so had to go outside to disconnect the car.