Wasatch Range Anxiety

[jwanderson88]

This story will curl your hair. It's one of those "I thought it couldn't happen to me" things. My sister and her husband and I were coming from Moab, Utah, in my Rivian yesterday. We stopped in Green River to charge at an Electrify America charging station. It was 124 miles to Fairview. I was able to get to 166 miles of range in conserve mode before there was a charging error and it stopped. I thought 42 miles was enough buffer, so I didn't try to add any more. We would cross the Wasatch Range (9800 feet elevation) right before getting to Fairview. It was fully dark when we began the climb to the top. At that point it was 45 miles to Fairview. Right away I began to see that I was using "estimated range" faster than actual miles traveled. When we had finally come to a lake near the top, snowplows had carved just enough of a path for two lanes of road through four or five feet of snow. There was nowhere to pull off. I know the road well and I knew that if we could make it to the top, it was downhill the rest of the way. The range was down to single digits and it looked like we wouldn't make it to the top. We were down to 2 miles of range when I said to my passengers "We might not make it." They didn't know anything was wrong. They took it well. I really didn't have any choice but to continue. Finally I was relieved to pass a snow kite park that was very close to the top. When we did finally reach the top, the range was down to 1 mile. It immediately began to accumulate range from regen on the steep slope on the other side. By the time I got home I had 14 miles of range. I was very lucky. I learned a valuable lesson, although I'm still not sure why the range estimate was so far off.

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[COdogman]

You must have done a good job hiding the terror of what was happening. My passengers would have immediately known something was wrong.

 

[PappaBolt]

That was a close call. I might have turned around and caught some regen on the way back to that EA charger to take on a little more fuel before making another attempt.

 

[zefram47]

The range displayed is sadly *always* based on the EPA range. If you use nav, it'll be much closer if not overly conservative in its estimates, but the range remaining on the driver display will still show EPA. This is why I rely more on %SoC than estimated miles. Take %SoC remaining / 100 * 130 kWh * approx efficiency in mi/kWh and you'll get a reasonable guestimate on range, assuming your trip meter efficiency represents the remaining drive. In the mountains, that's not going to be accurate at all. I know I'll get around 1 mi/kWh going up and over 4 mi/kWh coming down. Yes, it sucks to do math, but it'll prevent this sort of issue when you run numbers at the charger for the next leg. But again, the built-in nav tends to be pretty conservative and does take elevation change into account.

 

[goldburger]

When we did finally reach the top, the range was down to 1 mile. It immediately began to accumulate range from regen on the steep slope on the other side. By the time I got home I had 14 miles of range.

Whoa you accumulated that much on the downhill?

 

[jwanderson88]

What happened to me was the best case scenario. I made it. But one has to consider the worst case scenario. Crossing the mountain I didn't see a single vehicle. There was nobody. Cell phone service is spotty in places. If I did run out of charge I couldn't use my final momentum to roll off the road because there was a wall of snow. I'd be right in the middle of the road blocking traffic. Ev's won't coast. There are coal mines in the area and during shift changes there would be lots of cars barreling up the mountain., If I happened to have cell phone service in that spot I'd have to call highway patrol that I was blocking traffic and a tow truck. Good luck with that. If I didn't have cell phone service I'd have to wait for someone to come along or start walking.

On the east side it was a 34-mile climb to get to the top. It looked like I was using around 1.5 miles of estimated range for every mile I traveled. It is 113 miles from Green River to the highest point on the mountain and a 5700-foot change in elevation. You have to take that into account if you don't want to get into trouble.

What I'm wondering is if something like this will happen to most EV owners eventually. Also I'm wondering if people should carry emergency cones in case their car is blocking the road.

 

[Denver_Paulie]

What route did you take? Elevation gain, speed, and cooler temps always dictate taking the long way to hit an extra charger even if you think you don't need it.

I would have spent the extra 30 minutes to an hour and gone home via Salina just to hit the charger there. Or gone through Price and used the 50kWh charger there just to top off a little.

Getting stuck in the middle of no where Utah in the end of February is not my idea of fun.

 

[Scottm]

Were you just looking at the estimated range in miles or were you actually navigating to the next destination? The navigation would account for the altitude gain and I’m pretty sure it would have alerted you that you might not make it?

 

[jwanderson88]

I took the shortest route. Hindsight is 20/20. I could have done lots of things. I think I'm trying to help others avoid what happened to me. And to keep it from happening to me again. I always thought charging problems were just due to lack of planning. I never planned on it taking so much charge to climb 5700 feet. The DC fast charger in Green River could be the only one in the southeast quadrant of Utah. I've used level 2 chargers and it takes all day to get a few miles of range. But that's better than bricking.

 

[Aag12]

I've done the whole 'uh oh, the range of arrival keeps ticking down' butt pucker too. It is not fun!

Another tip for you is to just slow down and turn off the heaters. If you're on a highway get behind a truck.

Glad you made it!

 

[jwanderson88]

I was thinking about the 1-mile range display. Maybe it will say 1 mile as long as you can move and doesn't necessarily mean 1 mile. It will let you dip into the "reserve" in an emergency. I'm wondering if anyone has actually "bricked" a normally-functioning Rivian and what that was like.

 

[Billyt1963]

Your story touches on my biggest question about the Rivian. When you have a significant downhill can you take your foot off the pedal and coast without the vehicle stopping? I used to drive a hybrid and had to drive a mountain in middle TN often. By the time I got to the top the battery was near 0, but since I could coast down, it was full by the time I got to the bottom. I realize battery sizes are significantly different, but I wondered how much ”coasting” was allowed.

 

[Dark-Fx]

I carry a satellite messenger in situations where I might be out of cell service with very little hope of others crossing my path if something happens. I've successfully used it to get help in that situation already but haven't had to push the SOS button on it yet.

 

[R1Thor]

Disclaimer: THIS IS NOT ADVICE to take anything for granted or abusing the battery...

MotorTrend did decide to see how far a Rivian could go when completely draining the battery:
https://www.motortrend.com/reviews/2022-rivian-r1t-yearlong-review-update-10-running-out-of-battery/

FWIW: they made it an additional ~3 miles after the battery hit 0 SoC, so there IS a tad bit of fudge factor on the backend of the battery.

It's terrible for the battery, but so long as you're not making it a habit (read: it happens once..or twice in a blue moon), it should be OK.

I know that doesn't ...really help, but I think it's at least a little reassuring that if you're on that white knuckle cusp of eking out your trip, you're likely going to be more often on the side of OK.

Glad you made it home safe, OP

 

[usulio]

Thanks for sharing the story. I saw on the forums the estimate that 1000ft of elevation gain costs 10 extra miles of range on top of the distance you're driving. I think it might be closer to 5 miles but a safe rule of thumb.

Whoa you accumulated that much on the downhill?

Surprised me too. In the mountains of Colorado I rarely get more than 2% battery from a long downhill, partially because the regen gets limited. But I could see getting more at slower than highway speeds.

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