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Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 12:18 pm
by Honva
Just got my 2018 Leaf for about a week. I set charge timer to stop charge at 7:00am (end of cheaper rate) and climate control timer at 8:30am for pre-heat driving. I checked the status around 7:30am and found the car stopped charging and is at 81%. However, when I got into the car at 8:30, the warmer is on and the charge is at 87%. Looks like the car started charging again. Is starting the climate system always also make the car start charging? It is not quite desirable behaviour as electricity rate almost double at certain time of the day.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 12:29 pm
by LeftieBiker
Honva wrote:Just got my 2018 Leaf for about a week. I set charge timer to stop charge at 7:00am (end of cheaper rate) and climate control timer at 8:30am for pre-heat driving. I checked the status around 7:30am and found the car stopped charging and is at 81%. However, when I got into the car at 8:30, the warmer is on and the charge is at 87%. Looks like the car started charging again. Is starting the climate system always also make the car start charging? It is not quite desirable behaviour as electricity rate almost double at certain time of the day.


If the car is plugged in it will start charging when the climate control is activated.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 2:21 pm
by jjeff
LeftieBiker wrote:
Honva wrote:Just got my 2018 Leaf for about a week. I set charge timer to stop charge at 7:00am (end of cheaper rate) and climate control timer at 8:30am for pre-heat driving. I checked the status around 7:30am and found the car stopped charging and is at 81%. However, when I got into the car at 8:30, the warmer is on and the charge is at 87%. Looks like the car started charging again. Is starting the climate system always also make the car start charging? It is not quite desirable behaviour as electricity rate almost double at certain time of the day.


If the car is plugged in it will start charging when the climate control is activated.

And AFAIK the only way to pull power from the wall to supply the CC(climate control) is to activate charging. IOW if the EVSE is supplying power to the CC it also charges the battery(that is if your EVSE is capable of supplying more current than the CC draws). I've found in cold weather a 18a(240v) EVSE supplies just enough power to run the CC(heat) and not really charge the battery. A more amperage EVSE and you'll also gain SOC, less amps and you'll actually lose SOC during preheating. I'm talking about preheating in relatively cold MN where the heater runs much of the time during your preheating, in warmer climates or just warmer weather, you'll need less power to just run the CC and may actually gain SOC with a lesser amperage EVSE.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 2:37 pm
by LeftieBiker
IOW if the EVSE is supplying power to the CC it also charges the battery(that is if your EVSE is capable of supplying more current than the CC draws).


This is because power for climate control - and for every other accessory - is drawn directly from the battery, always. So the charging system only charges the battery, and the car powers everything from the battery, with the EVSE providing power for nothing but charging. So when preheating with "shore power" you are actually still using the battery, but replacing charge as fast as it's used, from the EVSE, if the EVSE can provide enough amperage. L-1 charging never provides enough power to replace all of the charge lost from preheating, while L-2 does if it's providing at least 20 amps, IIRC.

If the OP is concerned about the cost of the power used for preheating, they can use the same trick I use to minimize charge loss with my L-1 charging: set the climate control to only run for 5 minutes. That's long enough to heat the seats and wheel, and to bring the cabin temp up 5-10 degrees F.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 4:39 pm
by jjeff
LeftieBiker wrote:
IOW if the EVSE is supplying power to the CC it also charges the battery(that is if your EVSE is capable of supplying more current than the CC draws).


This is because power for climate control - and for every other accessory - is drawn directly from the battery, always. So the charging system only charges the battery, and the car powers everything from the battery, with the EVSE providing power for nothing but charging. So when preheating with "shore power" you are actually still using the battery, but replacing charge as fast as it's used, from the EVSE, if the EVSE can provide enough amperage. L-1 charging never provides enough power to replace all of the charge lost from preheating, while L-2 does if it's providing at least 20 amps, IIRC.

If the OP is concerned about the cost of the power used for preheating, they can use the same trick I use to minimize charge loss with my L-1 charging: set the climate control to only run for 5 minutes. That's long enough to heat the seats and wheel, and to bring the cabin temp up 5-10 degrees F.

Thats probably a better of explaining it than I tried :)
20a L2 is very close, I found with my EVSE where I could change the amperage in 1a increments that I'd ever so slightly lose charge at <18a @ 240v and gain charge at settings >18a, again depends on temperatures and note I have an S with only resistive heat, warmer temps with a heat pump Leaf could still charge the battery with a much lower amperage EVSE and yes, to work around the OP's issue a short morning warmup would be the best option.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 5:33 pm
by LeftieBiker
warmer temps with a heat pump Leaf could still charge the battery with a much lower amperage EVSE


Unfortunately, Nissan wasn't thinking about conserving charge when they programmed the system, because even heat pump equipped cars also run the PTC when preheating, as best I remember. mine sure seems to do it. They seem to have considered fast preheating to be more important than economical preheating.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 9:33 pm
by Honva
Thanks everyone for the time explaining it. Yes, I am on 32A L2 (the portable nissan charger that came with the car). Now I know why it is charging. Looks like it would work better for me to turn the climate timer off and just remote start it a few minutes before leaving using the app.

Re: Starting Climate System also start charge?

Posted: Fri Mar 30, 2018 9:35 pm
by LeftieBiker
Honva wrote:Thanks everyone for the time explaining it. Yes, I am on 32A L2 (the portable nissan charger that came with the car). Now I know why it is charging. Looks like it would work better for me to turn the climate timer off and just remote start it a few minutes before leaving using the app.


Yes, that should work best.

Re: Starting Climate System also start charge?

Posted: Fri Apr 06, 2018 7:49 am
by nerk
Might I add,

I love the heat pump! why don't all cars have it? even non-EV's! Amazing, instant heat!

Re: Starting Climate System also start charge?

Posted: Fri Apr 06, 2018 10:18 am
by BillHolz
nerk wrote:I love the heat pump! why don't all cars have it? even non-EV's! Amazing, instant heat!


Cars with internal combustion engines waste so much fuel making heat that using that heat during the winter is the easiest way to keep the interior warm. It just does not work until the engine warms up for a few minutes.