A/C effects on EV range ? Anyone know if cooling has an impact on battery range ?

Discussion in 'Clarity' started by 4sallypat, Feb 10, 2019.

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  1. 4sallypat

    4sallypat Active Member

    Since most folks are currently dealing with the winter effects (shorter days, longer nights, colder temps) - decreased EV range is due to extra use of headlights, seat heaters, cabin heaters, windshield defrost, rear window defog, etc... and subsequently causing a much lower EV range as everyone has been reporting.

    This past week with sunny nice weather, I have not had to turn on anything to load the batteries ( no seat heaters, no cabin heating, no headlights, etc) - just rolling down the window is all I needed and getting about 60 miles of range per charge....

    I know it's not hot enough in most areas of the country but being in So Calif, our weather goes to very hot, very soon.

    I wanted to know as our weather is changing in February to spring like - longer days, warmer temps and dry Santa Ana conditions:
    What is the impact of using the A/C cooling systems in our Clarity ?

    Does the A/C use the battery power from the 12V starting battery or the BEV battery pack ?

    Just wanted to know if warm weather states like So Cal would be seeing a decrease in EV range as a result of using the A/C system so much????
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  3. DucRider

    DucRider Well-Known Member

    AC use does impact range, but not nearly as much as the heater.
    A good rough estimate is 10% in very hot conditions.
    If you park in the sun and have multiple short trips, it is harder on the AC and will use more "juice"
    4sallypat likes this.
  4. KentuckyKen

    KentuckyKen Well-Known Member

    I’ve had my Clarity since Feb of 2018, so I’ve gone through one winter and one summer in Kentucky. Compared to winter, summer use of AC is far, far less a range killer. It’s so much less that a reformed old hyper miler like me ran the AC all summer and I still got high 50s to low 60s mile range.
    Some caveats here:
    I have ceramic, IR (heat) reflecting tint on all glass (including windshield) which significantly reduces heat gain and AC load.
    -I garage my Clarity which means the first trip each day is in a non solar heated oven.
    -I’ve found that just a minute on higher fan speed when first getting in when parked in the sun will let me dive the rest of the way on the two lowest fan settings (and I like it cold). That and the fact that for me ECON does not seem to adversely affect cooling comfort, seem to keep the AC power drain very reasonable.
    -I have the beige interior instead of the black which helps to absorb less heat
    -This held true for me even when it got up to high 90s F.

    So I’ve seen a much larger drop in EV range with cold weather (battery chemistry and resistance heat) than with hot weather use of AC. I’ve been very pleasantly surprised by that and by the fact that in my climate, preconditioning and seat heating have kept my winter range reduction reasonable. (Only went dow to mid 40s.)
    Our AC is very powerful since it cools very quickly and must be very efficient since it doesn’t reduce range all that much. I think you will be abe to chill out this summer and not worry about it.
    ClarityDoc, jdonalds and 4sallypat like this.
  5. Sandroad

    Sandroad Well-Known Member

    The A/C uses power from the main hybrid battery. The 12V starting battery is not used as a power source for accessories when the car is on, but some power does pass through it for a few things. The temperature differential is much less in the summer than in the winter here in Michigan. For example, the temperature could be as much as 80F different inside vs. outside in the winter, but only a maximum of about 20F different inside vs. outside in the summer. That, plus the much greater capacity of the chemistry in the battery during summer temps, makes for a way smaller effect on the range when using A/C vs. using the heater. However, any energy drawn from the main battery for anything other than propulsion will lower range.
    4sallypat and BobS like this.
  6. MNSteve

    MNSteve Well-Known Member

    Other folks have answered your actual question. I just want to mention that the only significant range reducers are the resistance heating and the AC, and the AC appears to be much less a factor than the heat. Headlights, seat heaters, rear window defog ... basically anything that is powered by the 12 volt battery, is an insignificant factor compared to the ones that are powered by the HV battery. The cabin heat really uses a lot of energy.
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  8. insightman

    insightman Well-Known Member Subscriber

    I wonder about how ECON Mode affects the operation of the climate control system but not enough to switch out of ECON Mode.

    One place in the Owners Manual (see below) cites an ECON Mode effect on cooling performance, but doesn't mention heating performance. Another place says ECON Mode adjusts the performance of the climate control system without reference to heating or cooling.

    Another paragraph prepares us to expect greater temperature fluctuations in ECON Mode. Because that paragraph doesn't mention either heating or cooling, I guess we're supposed to expect the greater fluctuations to occur with both heating and cooling.

    I wish the Owners Manual would just tell us how ECON Mode affects the operation of the climate control system instead of telling us simply to expect reduced performance and greater temperature fluctuations. In particular I would like to know the effects of ECON Mode on range-robbing electric heating.

    Sometimes the engine runs in ECON Mode in response to post-click accelerator-pedal activity or in response to the selection of high climate-control fan speeds in cold weather. Does ECON Mode affect the climate control system when the engine is running or just when the battery is providing the power for heating?

    Page 195 of the Owners Manual mentions the potential effect of ECON Mode on cooling only:
    While ECON mode is active, the climate control
    system may have reduced cooling performance.

    However, page 388 of the Owners Manual doesn't imply the effect of ECON Mode is restricted to cooling:
    The ECON mode helps you improve your energy economy by adjusting the
    performance of the climate control system and the accelerator pedal response.

    and in the sidebar on the same page:
    While in the ECON mode, the climate control system
    has greater temperature fluctuations.

    When the ECON mode is active, the driver’s side seat
    heater functions according to the status of the
    climate control system. If you want to use only the
    climate control system, press the seat heater button
    to OFF.
    Last edited: Feb 10, 2019
    Johnhaydev and ClarityDoc like this.
  9. The Clarity is a fickle beast when it comes to climate control. I started mine in about -12C weather, turned on driver’s heated seat to level 3, turned on rear defrost, set the heat to 22C and set the fans to 1-2 notches above the midpoint and everything ran smoothly. My windshield started to fog up from my body heat so I flipped on the front defogger and the ICE immediately kicked in. I was curious if there was a direct correlation to switching the defogger on so I switched it off and the ICE turned off instantly. Not really sure how relevant this is but it was fascinating behaviour.

    Sent from my iPhone using Inside EVs
    4sallypat likes this.
  10. insightman

    insightman Well-Known Member Subscriber

    The ICE didn't even run long enough to warm itself up? I thought it always runs long enough to warm itself up unless you pull over, turn off the car and restart it (which, of course, is not recommended).
  11. It was on for literally seconds. As soon as I hit the windshield defogger button the ICE kicked in and it was no more than 15 seconds before I turned it off out of curiosity and the ICE went off no more than 1 second after.

    Edit: It should be noted that this all took place while the vehicle was in Park.

    Sent from my iPhone using Inside EVs
    Last edited: Feb 11, 2019
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  13. MNSteve

    MNSteve Well-Known Member

    I am also surprised that the ICE didn't come to temperature. But I guess I've never tried exactly what you did; I just assumed that the ICE wouldn't turn off until it was toasty. We all know about that word, "assume".

    The reason the ICE started was not exactly that you turned on the front defogger, but that when you do this you implicitly turn the fan to max. I've observed exactly the same behavior in terms of the ICE starting if I request lots of heat from a high fan speed, and it turning off if I knock the fan speed down to low.
  14. 4sallypat

    4sallypat Active Member

    Thanks to all of you for chiming in !

    This car is certainly a new form of education for me - learning a lot of new tech never experienced in over 40 years of driving.

    @Kyle’s Clarity agreed this car has fascinating behavior......
  15. LAF

    LAF Active Member

    I have noticed that with a black interior- if the car is in the sun even on the coldest days the interior starts out a lot warmer than the exterior. Since EV is more sensitive to heating than AC- this could be a factor for some deciding on which interior to get.
  16. KentuckyKen

    KentuckyKen Well-Known Member

    Yeah, it’s a trade off. Since I never had a white car before, I took the beige and rationalized that since I’m not that far north that the slight summer benefit would outweigh the slight winter one. Now that I know the AC takes far less power than the heat, I think it can be argued both ways depending on where you live.

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