Scary range anxiety day!

[Doug_G]

Surprisingly I've never had Range anxiety. When I first got my Roadster there were NO charging stations around. The first road trips I did were carefully and conservatively planned - spreadsheets, the works. The car performed in accordance with Tesla's predictions. From there I learned how to manage range so if I had to push things, I just slowed down EARLY so I didn't get into trouble. And I occasionally got pretty cold.

On one occasion a reporter really wanted a highway demo when I was already low on power - there was no way I'd make my destination afterwards. No problem, I had a fallback charging location in my pocket. I did get a little below what I consider my minimum range buffer, but despite the warning messages I knew I'd definitely make it. So I wasn't anxious.

What I have had on occasion is "schedule anxiety". On one memorable trip the temperature was unexpectedly cold, and I was running A048 sticky tires for the first time. It turns out that freezing temperatures turn them into bricks. I had no idea just how bad an effect this would have on range. But it was very obvious early on so I slowed down. The only charger available provided only 24A, so I spent a LOT more time than planned charging. This resulted in me getting caught in Toronto rush hour on top of all that. I very nearly missed a flight as a result (running was involved!).

[brianman]

Surprisingly I've never had Range anxiety.

When you first got the vehicle, were you charging at home on 110/12 or something higher?

[Doug_G]

When you first got the vehicle, were you charging at home on 110/12 or something higher?

Higher - I had a Roadster HPC installed before the car arrived - 240V 70A.

[Liz G]

I had a similar stressful day yesterday. I didn't charge the night before because we had thunderstorms but I thought I'd be ok as I had 211miles of rated range. I drove to the gym and back, went to work, and then out to lunch with a friend. When I got back from lunch I had 119 miles of range. I still had about 60 miles worth of driving to do so should be able to do that easy. Well that "easy" feeling quickly dissipated when I returned to my car after work and I had 94 miles of range. I had lost 25 miles of range in 4 hours while the car sat in 32 degree F weather. This I was not prepared for. I called Tesla and they indicated that this was do to a faulty algorithm that didn't take ambient temp into account. So I figured I was still fine. So I drove down to my appointment, had to get some bubbles in my paint armor repaired. Interestingly when I arrived at the shop I had 78 miles of rated range but after the car sat in their warm garage for about 45 mins I had 81 miles. So I went out to dinner and then drove home the remaining 34 miles with about 76 miles of rated range. Ended up getting home with 19 miles of rated range. It should be noted that the heater basically turns off when you get that low though the heated seats still work.

I'm still not sure how many miles of range I truly had, especially since I seemed to gain range while sitting in the shops heated garage. Bu I've learned 2 leasons. 1 always plug in at night or whenever home, wish I'd plugged in after going to the gym, and leave with a full charge. 2 sitting in the cold I will loose about 6 miles of range so watch the weather and take that into account when planning my day.

[brianman]

Higher - I had a Roadster HPC installed before the car arrived - 240V 70A.

I suspected. The only time I've had any rational range anxiety was when I was charging on a mere 110/12 at home. Ever since getting the 14-50R (240/40), it's been a non-issue.

[Krugerrand]

Agree completely...it's (the white knuckle range anxiety trip) kind of a rite of passage required to cure range anxiety...

Yeah, but who hasn't experienced that a time or two in an ICE? I happen to know EXACTLY how many km's I can go in my minivan after the needle hits E.

[Doug_G]

I'm still not sure how many miles of range I truly had, especially since I seemed to gain range while sitting in the shops heated garage.

There are actually two things to consider.

First, as you have recognized, if the pack is cold then the mileage will display lower than what is actually available. This "lost" range will magically reappear if the pack is warmed up. If you warm up by driving the number won't actually go up, because you are after all using power to drive, but the display will go down more slowly than it should. Once the pack is warmed up the display will be accurate.

The second thing matters when it is extremely cold, say -20C (-4F). If the car has been sitting out in that for a couple of hours, the pack heater goes on full power at first. By the time the battery is warmed up (something like 20 minutes) the heater could easily have consumed 3 kWh (~10 miles). Also you would be using a fair bit of cabin heat; at full power that could consume ~20 miles per hour. Again, once the pack and the cabin warms up the extra power draw will be less.

The upshot here is if you are planning a long trip you should charge immediately before leaving. That way the pack is already warm.

[stevezzzz]

Pilots know in their bones that the most useless things in aviation are altitude above you, runway behind you, and air in the fuel tanks. In a similar vein, for EVs, I offer these rules of thumb:

1. Never pass up a charging opportunity!
2. When in doubt, slow down. You can always speed up later.*
3. Never pass up a charging opportunity!
4. "Rated Miles" range is optimistic. "Ideal Miles" range is a fantasy.**
5. Never pass up a charging opportunity! ***

* This is especially true if you have a multi-leg trip with charging stops en route. Slowing down 10mph almost always results in a reduced overall time en route because you'll more than make it up by spending far less time charging, unless you're lucky enough to have a Supercharger where you need it.
** Unless you're willing to wait for perfect weather and road conditions on a flat course with no wind, and have the bladder of an 18-year-old combined with the patience of Job.
*** By "charging opportunity", I don't mean you have to stop at every L1 charger you happen to pass along the way: it refers to those times when the car is sitting idle within reach of a charger and all you have to do is plug it in.

[bonnie1194]

Pilots know in their bones that the most useless things in aviation are altitude above you, runway behind you, and air in the fuel tanks. In a similar vein, for EVs, I offer these rules of thumb:

1. Never pass up a charging opportunity!
2. When in doubt, slow down. You can always speed up later.*
3. Never pass up a charging opportunity!
4. "Rated Miles" range is optimistic. "Ideal Miles" range is a fantasy.**
5. Never pass up a charging opportunity! ***

* This is especially true if you have a multi-leg trip with charging stops en route. Slowing down 10mph almost always results in a reduced overall time en route because you'll more than make it up by spending far less time charging, unless you're lucky enough to have a Supercharger where you need it.
** Unless you're willing to wait for perfect weather and road conditions on a flat course with no wind, and have the bladder of an 18-year-old combined with the patience of Job.
*** By "charging opportunity", I don't mean you have to stop at every L1 charger you happen to pass along the way: it refers to those times when the car is sitting idle within reach of a charger and all you have to do is plug it in.

+1. Let me add two more:

6. Always plug in. Always.
7. Never pass up a charging opportunity!

- - - Updated - - -

8. When on a roadtrip, always have enough range to get to the charging station beyond the station where you're planning to charge. That way if the spot is occupied or nonfunctional, you have another option.

[Doug_G]

9. When possible, always go for the higher power charger
10. Never pass up a charging opportunity!

Unfortunately, Bonnie, around here #8 is pretty much impossible. Charging infrastructure is still pretty thin. Some day I'm going to show up and find the plug occupied, and am going to be in trouble!