Extreme Heat's Effect on Range

[Buffalo Bob]

Sorry for the novel... I'm planning to depart on a trip from AZ to WA this weekend. Following both this forum's and one of ABRP's recommendations, my current plan is to travel from Phoenix to Flagstaff, charge up, and then travel about 270 miles to St George, Utah to charge again. The problem is that there seems to be no truly reliable chargers en route. (There is a ChargePoint location at around 210 miles in Kanab, Utah with a PlugShare score of 10, but all of the chargers were noted as broken on 6/3/24.) If I charge my Pure AWD to 95% in Flagstaff, I would have to average at least 3.1 miles/kWh to make it to St. George. Given that this is a cooler (higher elevation) route with a net elevation decrease and lower non-freeway speed limits, achieving 3.1 miles/kWh seems very doable, and well below my 3.7 average, but that possible lack of alternative charging concerns me.

The are alternative routes through LA and Las Vegas with more charging options, but they involve a lot more desert travel on a weekend when record-breaking heat dome temperatures are expected, and the more remote chargers in places like Quartzsite don't have the greatest reputation.

My biggest question is what people have experienced range-wise when driving in something like 110 degree heat, and the car is working hard to cool both the batteries and the interior, as even these alternate desert routes do have fairly long intervals between chargers.

Perhaps I'm overthinking this, but the heat-related part of the equation is new to me. Any advice would be greatly appreciated.

 

[xponents]

Sorry for the novel... I'm planning to depart on a trip from AZ to WA this weekend. Following both this forum's and one of ABRP's recommendations, my current plan is to travel from Phoenix to Flagstaff, charge up, and then travel about 270 miles to St George, Utah to charge again. The problem is that there seems to be no truly reliable chargers en route. (There is a ChargePoint location at around 210 miles in Kanab, Utah with a PlugShare score of 10, but all of the chargers were noted as broken on 6/3/24.) If I charge my Pure AWD to 95% in Flagstaff, I would have to average at least 3.1 miles/kWh to make it to St. George. Given that this is a cooler (higher elevation) route with a net elevation decrease and lower non-freeway speed limits, achieving 3.1 miles/kWh seems very doable, and well below my 3.7 average, but that possible lack of alternative charging concerns me.

The are alternative routes through LA and Las Vegas with more charging options, but they involve a lot more desert travel on a weekend when record-breaking heat dome temperatures are expected, and the more remote chargers in places like Quartzsite don't have the greatest reputation.

My biggest question is what people have experienced range-wise when driving in something like 110 degree heat, and the car is working hard to cool both the batteries and the interior, as even these alternate desert routes do have fairly long intervals between chargers.

Perhaps I'm overthinking this, but the heat-related part of the equation is new to me. Any advice would be greatly appreciated.

There has been research pertaining to this that show EVs losing 20-30 percent of their range when the temperature is above 95 degrees, this can be seen by googling “extreme heat evs.” Therefore, I would prepare for an ABSOLUTE worst case scenario of about 240 miles of range (using extrapolation with your 3.7 average). This would lead to 2.6 mi/kwh, which is lower than what you would need.

This rule may not apply to the Air, though. I have not come upon a “rule” for the Airs, but the 20-30 percent range loss seems to be a common guide for EVs.

 

[BS8899]

Sorry for the novel... I'm planning to depart on a trip from AZ to WA this weekend. Following both this forum's and one of ABRP's recommendations, my current plan is to travel from Phoenix to Flagstaff, charge up, and then travel about 270 miles to St George, Utah to charge again. The problem is that there seems to be no truly reliable chargers en route. (There is a ChargePoint location at around 210 miles in Kanab, Utah with a PlugShare score of 10, but all of the chargers were noted as broken on 6/3/24.) If I charge my Pure AWD to 95% in Flagstaff, I would have to average at least 3.1 miles/kWh to make it to St. George. Given that this is a cooler (higher elevation) route with a net elevation decrease and lower non-freeway speed limits, achieving 3.1 miles/kWh seems very doable, and well below my 3.7 average, but that possible lack of alternative charging concerns me.

The are alternative routes through LA and Las Vegas with more charging options, but they involve a lot more desert travel on a weekend when record-breaking heat dome temperatures are expected, and the more remote chargers in places like Quartzsite don't have the greatest reputation.

My biggest question is what people have experienced range-wise when driving in something like 110 degree heat, and the car is working hard to cool both the batteries and the interior, as even these alternate desert routes do have fairly long intervals between chargers.

Perhaps I'm overthinking this, but the heat-related part of the equation is new to me. Any advice would be greatly appreciated.

I drove my AGT this past Saturday (Jun 1) from Phoenix to Marin County. I don't recall the temperatures, but they are probably in the 90s-100s. I set the speed @75mph. I was getting about 3.6-3.7 miles/kWh. If you drove at 80-85mph, it will be substantially lower. I found speed is the major modulator.

 

[BS8899]

I drove my AGT this past Saturday (Jun 1) from Phoenix to Marin County. I don't recall the temperatures, but they are probably in the 90s-100s. I set the speed @75mph. I was getting about 3.6-3.7 miles/kWh. If you drove at 80-85mph, it will be substantially lower. I found speed is the major modulator.

I travelled on I-10/I-215/I5. Therea re plenty of charging options en route.

 

[Adnillien]

When I have driven in 118 degree heat I notice about a 10% loss in efficiency compared to the same drive at 95 degrees.

 

[Buffalo Bob]

When I have driven in 118 degree heat I notice about a 10% loss in efficiency compared to the same drive at 95 degrees.

Thanks. Is 95 about normal?

 

[Steveinarizona]

Thanks. Is 95 about normal?

In the winter.

 

[TLamm7751]

I drove about 75 miles yesterday with exterior temperature of about 90 degrees. The car had been sitting outside, so it needed a lot of A/C. For that 75 miles, driving about 75mph average, the efficiency was around 2.5-2.6kw. I noticed it starting to improve a bit toward the end of the drive when the A/C had finally stabilized, etc. If I went 100 miles instead, probably would have seen an overall overage of 2.8 or so. But, then again, 90 isn't really that hot. If I were personally "budgeting" my stops, I would probably use 2.5kw to be conservative.

 

[Steveinarizona]

I drove about 75 miles yesterday with exterior temperature of about 90 degrees. The car had been sitting outside, so it needed a lot of A/C. For that 75 miles, driving about 75mph average, the efficiency was around 2.5-2.6kw. I noticed it starting to improve a bit toward the end of the drive when the A/C had finally stabilized, etc. If I went 100 miles instead, probably would have seen an overall overage of 2.8 or so. But, then again, 90 isn't really that hot. If I were personally "budgeting" my stops, I would probably use 2.5kw to be conservative.

Elevation changes can also make a big difference.

Yesterday in my Genesis I was driving home very fast, passing others on the highway and city streets, with the temperature at 101 and going from about 1180 ft above sea level to 1440 feet above sea level for 24 miles. AC on full after car had been sitting in the sun for four hours. My lifetime average is 3.0 and I averaged on this trip about 2.4. If I had been going in the other direction I would likely have averaged around 3.0 driving the same route and style (except for direction). So, all other things being equal, elevation changes make a great difference as well.