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Go Times

Posted: Fri Jun 20, 2014 10:10 am
by EVA
Does anybody know how much electricity the car uses if Go Times are set to climate off?

I have a schedule of Go Times I set up for the school year. Now that summer vacation is here, there's no need for Go Times. I had them set to 65 degrees to get the car cool before leaving on a hot day. I'd rather not waste the electricity needlessly cooling the interior. And I'd rather not go through setting up the schedule again, if I can avoid it.

So today I set all the temperatures to Off. How much extra electricity does the car still use with the interior temp set to off?

Re: Go Times

Posted: Fri Jun 20, 2014 12:01 pm
by hybridbear
EVA wrote:Does anybody know how much electricity the car uses if Go Times are set to climate off?

I have a schedule of Go Times I set up for the school year. Now that summer vacation is here, there's no need for Go Times. I had them set to 65 degrees to get the car cool before leaving on a hot day. I'd rather not waste the electricity needlessly cooling the interior. And I'd rather not go through setting up the schedule again, if I can avoid it.

So today I set all the temperatures to Off. How much extra electricity does the car still use with the interior temp set to off?
It shouldn't use any. If the climate is set to "Off" then the only function of the Go Time is to make sure the battery is fully charged by that time. The car will try to charge during the cheapest time according to your value charge profile, but will charge even when electric rates are high in order to be charged for a Go Time.

Re: Go Times

Posted: Fri Jun 20, 2014 12:14 pm
by jmueller065
hybridbear wrote:If the climate is set to "Off" then the only function of the Go Time is to make sure the battery is fully charged by that time.
Not necessarily, the Go Time is also used to precondition the battery was well. Thus even if the climate is set to "off" the car may still do something with the battery (heating/cooling). Granted in these mild temperatures it shouldn't do much.

I was going to setup one for tomorrow and check the power consumption at the specified Go Time.

Re: Go Times

Posted: Sat Jun 21, 2014 2:25 am
by jmueller065
Here was my test setup:
  • Car fully charged parked inside garage
    Garage ambient temp 72F (measured by the opener--yeah don't know why they put a temp gauge on the opener!)
    At 5:55am (yeah I'm an early riser) programmed the go time for 6:15am with HVAC off
    Sometime before 6:10am the EVSE relays clicked on (6:10am is when I walked out to check)
    At about 6:12am or so (~3 minutes to go) the fan turned on and the Juicebox read 7A, 1.7kW
    Right at the go time of 6:15am the car shut down (but the EVSE relays stayed on)
    Total power consumption on the display was 0.0 kWh
So I guess about 3 minutes of 1.7kW isn't enough to even register at or above 0.1 kWh.

Doing a little math: 1.7kW = 1680 (7A * 240V), 3 minutes is 0.05 hours thus the total power consumption would be 84 Wh--yeah not much at all (maybe 2/5 a mile @ 200 Wh/mile).

I have noticed that I get a very slight reduction in power consumption on my morning commute if I use the go time set with climate off (like a 1% reduction in consumption). I mentioned it to my coworker and he has been attempting to verify it without that much luck. The above numbers would indicate that there is a reduction in consumption by using the go-times but it is so negligible that it is probably buried in the noise.

Re: Go Times

Posted: Sat Jun 21, 2014 10:40 pm
by EVA
JMueller - thank you so much for that test. That answers the question, I can leave the schedule and not worry about wasting significant electricity.

By reduction in consumption, you mean more power available? As in the battery works better if there is a go time scheduled with no climate. Seems like that would stand to reason, if the fans come on, the battery is probably getting to an ideal temperature - warmer or cooler.

Re: Go Times

Posted: Sun Jun 22, 2014 2:25 am
by jmueller065
Yes, more power available.

Re: Go Times

Posted: Wed Jun 25, 2014 3:45 am
by jmueller065
Update:
I've left my go times set with climate off for the week. This morning I glanced over at the Juicebox before unplugging:
24A! 4 minutes 0.3kWh consumed. (The math works out to 384 Wh.)

The only real difference was the weather: Ambient temp was a bit higher at 77F but the humidity is much higher than it was on Saturday.