jray3
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Re: Climate control confusion. Range projected drops when fa

Tue Jul 16, 2013 1:53 pm

RobbW wrote:The two or three times I have turned on the A/C, I noticed an immediate ~10 mile drop in my RR gauge.
So, I have a question about the use of CC and any drop in RR. Is this immediate drop in RR pretty much the only alarming thing I should see? Is the i-MiEV somehow calculating the estimated reduction in range and taking the number right off the top? Or will I see both that immediate drop in range AND an exponentially greater decrease in my range as I continue to drive and use the CC?


Robb, your 10 mile RR redux is exactly what most of us have seen, it will stick, and I'll say you won't see further penalties. I'm using air conditioning or heat unless I need to go farther than about 45 miles.
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acensor
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Re: Climate control confusion. Range projected drops when fa

Tue Jul 16, 2013 2:05 pm

Hi Robb.

You wrote, in part---
"So, I have a question about the use of CC and any drop in RR. Is this immediate drop in RR pretty much the only alarming thing I should see? Is the i-MiEV somehow calculating the estimated reduction in range and taking the number right off the top? Or will I see both that immediate drop in range AND an exponentially greater decrease in my range as I continue to drive and use the CC?"

It is my distinct impression that, as you speculate, the RR computer is indeed calculating the estimated reduction in range and taking the number right off the top.
Saying "if you keep driving with the AC (or heat) on based on that and the way you drove the last 15 miles this is how far I think you'll get.
Notice that if you promptly turn the CC back off the RR meter rather promptly restores the estimated range remaining back up the 10 miles it knocked off a few seconds ago.
Alex
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Don
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Re: Climate control confusion. Range projected drops when fa

Tue Jul 16, 2013 2:38 pm

Yes, the RR drop is greatest when you turn the A/C on with a full charge because it's computing the total range lost for the full trip - As far as it predicts the charge can take you. If you did the same thing with the battery half charged, the RR drop would be half of the 10 miles you saw

How far you have the temp dial set into the A/C range, and how fast you have the fan blowing affects how much RR is lost - Less of either will give a lower drop. In my experience, I believe the car's thermometer is taken into the equation as well. You'll see a bigger RR drop on a 95 degree day than on an 85 degree day

If the loss of range running the A/C in the summertime shocks you, just wait until WINTER when you switch on what passes for a heater - The RR drop will be more than triple . . . . and you still won't be comfortably warm. Preheat the car before you leave everyday for sure!

Don
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BillThompsonMIEV
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Re: Climate control confusion. Range projected drops when fa

Tue Jul 16, 2013 5:12 pm

My experience is that use of A/C causes a 12-15% reduction in RR.

BenBrown
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Re: Climate control confusion. Range projected drops when fa

Tue Jan 27, 2015 8:43 pm

I've wondered about climate controls and am looking forward to trying them out beyond my test run of an i-miev... in the next couple of weeks.

With the Leaf, I've discovered I can turn off the heat/or a/c and simply use the fan to clear away any fogging with absolute minimal draw to the battery. Has anyone else found the same technique can be used on an i-miev? I'm dressed for the outside weather when I get in the car anyway. The seat heating and heated steering wheel in the Leaf normally makes it comfortable enough. The main challenge is keeping the windshield clear, which, simply periodically turning on the fan w/no heat or cold seems to meet my needs and prolong the range. It would be SO good if I can do this in the i-miev.

fjpod
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Re: Climate control confusion. Range projected drops when fa

Wed Jan 28, 2015 2:11 am

I often do it. With no heat or a/c, it preserves your range.

PV1
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Re: Climate control confusion. Range projected drops when fa

Wed Jan 28, 2015 4:24 am

A pair of Thinsulate gloves, a heavy coat, heated seat, and the fan on one click if needed is how I roll. Lately though, I've been experimenting with having the heat on one click. This heats the liquid to around 85 F. Once the loop is up to temperature, the heater pulls around 1,000 watts, which is less than a bar for a drive less then 30 minutes.

I've also been looking at splicing the motor coolant and heater loops together to warm incoming air to at least 50 F, depending on terrain and speed. Highway heats the coolant the most, but a hilly route around 40 mph works too. Power shutters blocking air from passing through the radiator are needed though, and needed to regulate coolant temperature.

The controls for the climate control in the i-MiEV are great. They allow for full manual control of the system. The only automated function is when going to full defroster, the system activates AC and draws fresh air, but both are easily overridden and the settings stay until air is directed away from the windshield, regardless of fan speed and temperature setting. Air can be directed anywhere even when the fan is off.
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iwatson
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Re: Climate control confusion. Range projected drops when fa

Wed Jan 28, 2015 10:02 am

The imiev is my wife's car. She and I apparently drive very differently.

Most all her trips are short and thus the i's computer realizes that she has a low average speed. When she turns on the heat it has a big effect on the RR meter. In other words, the car figures that she will be driving at a low average speed, but with heat going which is a big draw against available energy.

On the hand when I drive her car I travel further distances, which means a higher average speed. Even though we all know that as you drive faster the car consumes more energy than slower, when stopped the car consumes little if any energy (just enough to keep the brake lights on). So you could park the car turned on without any accessories on and sit for a long time with no reduction in range. But when you turn the heater on under the same circumstances RR would continue to decline down to nothing (Zero) without ever going anywhere.

So my point is...as an example we went to dinner a few nights ago and used the heater. When we started out we had a RR estimate of 48 miles. When I turned the heater on it changed to 34 miles. I was driving the car, but my wife had been the sole driver for the last few days. after traveling about 5 miles with the heater on, I looked down and the RR meter had adjusted to my driving and was now reading 37 miles. We went another 4 miles to the restaurant and upon arrival the meter still read the same 37 miles.

So the imev's computer uses average speed to determine the heater's effect on range. The faster you go with the heater on the more range you'll get. The slower or stopped vehicle will use range more quickly because the heater is a constant energy draw, regardless of vehicle speed.
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JoeS
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Re: Climate control confusion. Range projected drops when fa

Wed Jan 28, 2015 12:42 pm

iwatson wrote:...as an example we went to dinner a few nights ago and used the heater. When we started out we had a RR estimate of 48 miles. When I turned the heater on it changed to 34 miles. I was driving the car, but my wife had been the sole driver for the last few days. after traveling about 5 miles with the heater on, I looked down and the RR meter had adjusted to my driving and was now reading 37 miles. We went another 4 miles to the restaurant and upon arrival the meter still read the same 37 miles.
iwatson, you've presented an interesting supposition. Traditionally, I would expect to see the RR plummet after driving a while at increased speed and I wouldn't expect the RR algorithm to do anything other than take a percentage off the RR as a function of heater energy consumption. In the example you used, I would have attributed the range increase due to the heater turning off or reducing its current draw after it had warmed up the fluid.
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PV1
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Re: Climate control confusion. Range projected drops when fa

Wed Jan 28, 2015 12:51 pm

I find that interesting, as well, but not really surprising.

Measuring the consumption of my heater at different settings, the heater runs at full power until the loop is at temperature, at that point, it only uses as much as necessary to maintain temperature. With the car stationary with 20 F ambient and the heater at 1 click into the red and fan at full speed, the heater jumps between 1,000 watts and 0. If I turn the temperature up a click, it'll use 2,000 watts until up to temperature, then drop back down. Turning the temperature down, it'll run for a few minutes and not pull anything, though the pump is still running. Turning the top knob to the green dot results in an increase in RR and an immediate drop in temperature of the air coming out of the vents since the pump shuts off. Click it back into the red, and the heat comes right back since the pump turns on.

It seems that the car does an immediate RR reduction, then continues calculating RR based on car and heater usage.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015
"Photon" - 2017 Bolt EV LT in Orange with QC - 7/31/2017

Solar-powered since 10/10/2013

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