Heat affecting EV range

  • Thread starter Thread starter coutinpe
  • Start date Start date
  • Replies Replies 9
  • Views Views 2K
coutinpe

coutinpe

Active Member
What I hear most of the time is that it's really cold temperatures what reduces EV range. However, in a couple of REALLY hot summers of '23 and '24 I noticed a dramatic decrease in range. Last year in Vegas, before the 110's arrived I was making 60-62 miles, but when the heat hit it went down more than 10 miles, to 48-49 , although immediately after fall arrived I got back to the 60s. Now after moving to the Phoenix area in March, range went down to the mid 50's (now I live on a hilly area) until mid June, when we started having >105F, and my range dropped to 47-48. Now in July, with 110-117F, my range is down to 40-42. I measured the battery capacity, but it only dropped a bit respect to last year, from 50.2 Ah to 49.9. Curiously, I didn't notice such a significant range drop in the summer of '22, but unfortunately I have no capacity readings from back then. Anyone in similar hot conditions have the same observations? Might this range drop be somehow linked to the air conditioner problem? It failed on me last summer right after I noticed the range drop and I'm dreading it might fail this summer too...
 
Yes, my range estimate dropped significantly before the A/C failed, and has gone back up as soon as I got it replaced. I do wonder if there's any other device in the car that would start using drastically more energy as it fails and cause the range estimate to lower.
 
Around town I am fine driving at temps up to 95 degrees with no AC and windows open, and I find that the hotter the temp the better the range. Maybe that changes at higher temps, or maybe the lower ranges you found are just due to more AC use. Even a correctly functioning AC uses a lot of juice. I generally don't even use the fresh air fan unless its raining, it cuts about 2 miles from my available EV range. It doesn't matter to have it off with all the windows open anyway.
 
This is actual data from a Tesla Model Y, but it is likely that similar principles apply. The temperature is in Centigrade:

upload_2024-7-14_19-55-41.webp

It is interesting to note that the "optimum" temperature is 25C. Above, or below 25C and the range deteriorates.
The best performance occurs at a speed of 40 mph and a temperature of 25C.

This vehicle has an EPA rating of 279 miles which it can achieve (or exceed) up to 70 MPH+.
 
With so many brilliant ideas circulating around the forum lately, it seems to be an appropriate time to share one more.

A little known technique, called the Bellows Maneuver, which can help EV owners increase range by reducing the amount of stored energy that would
otherwise be used for climate control in hot, sunny areas can work wonders. The procedure involves opening the passenger window to create a 1” gap at the top. This can be done before exiting the car if the owner is confident that there will be no rain or break in attempts. Upon arrival at the car, which has been baking in the scorching sun, the owner should open the driver’s door approximately half way and then close it to just shy of the point where it would latch closed. Do this 2-3 dozen times in rapid succession, or until all the hot air inside the cabin has been pumped out the cracked passenger window and the interior has reached ambient temperature. An additional 10-12 “pumps” may be necessary to cool the seats and steering wheel.

Be sure to have a bottle of drinking water on hand and enjoy the additional range.
 
Or maybe using the A/C precondition when the car is still plugged-in/charging could also help extend range. (Although this won't be likely a possibility if the car was baking in the scorching sun, i.e. not in a garage).
 
coutinpe said:
Or maybe using the A/C precondition when the car is still plugged-in/charging could also help extend range. (Although this won't be likely a possibility if the car was baking in the scorching sun, i.e. not in a garage).
Click to expand...

My Clarity sits in the driveway, often in scorching heat (100-115 degrees), and pre-conditioning to cool the car works great (when connected to a level 2 charger). It does take a fair amount of time too cool it down, though.
 
Been trying the A/C preconditioning for several days before driving out (usually in the mornings, still below 110F), but the range keeps creeping down. So it's either the high temps affecting the battery(even if not driving while >110F), or perhaps it's the A/C heralding its imminent demise once again, as reported by @petteyg359. Time will tell...
 
Well, lithium batteries do not like high or low temps so the decrease is probably normal. Winter time in chicago I get about 23 miles on the battery. Spring and fall I get about 51. On the hot summer days I get about 47 On a 2018 touring with 51k miles.
 
You must log in or register to reply here.
Back
Top