So, I Broder-ed my car this weekend...

[Spurkey]

It was only a matter of time before some other dipshit did it, sadly that dipshit turned out to be me.:frown::redface: I attempted to drive from my house in Edmonton to a hotel in Calgary, a 290km trip, with a full 'Standard' charge of 383km ideal. I didn't set it to a 'Max Range' charge because I figured that 90km of extra charge was enough of a buffer and that I didn't need to risk 'negatively impacting battery life' as stated on the charge screen. The battery depleted with 6km to go. This was the first major road trip with the car and I wasn't familiar enough with the various distance estimates the car provides when highway driving compared to city driving. The service I got from Tesla was fantastic and I was at the hotel plugged into a charger within an hour and a half. That's the short story.

The long story starts out the same, charged to full Standard. It was -1°C when we left, I'd run the cabin heater for about 5 minutes while plugged into wall power to get some heat in the car. I should probably point out that I don't frequent this forum as often as I should so I've missed out on many of Doug_G's informative posts about cold weather driving. The car had me plus a passenger with very light luggage, we were only going for the night. We unplugged & set off, we had the cabin heat to 21°C, the rear defrost on, and were soon doing 120km/hr (limit on Highway 2 is 110). My car has the 4.3 (1.24.45) software, we saw a huge power draw (+300Wh/km Like other battery drainers before me I didn't take good notes...) on the usage graph which didn't decrease after the defrost turned off, I assume now it was the pack heater. We assumed that draw was hugely skewing the projected distances so we ignored the dire projections & drove on. 57km into the trip, this part I did take notes of, we noticed that the draw was moving off the graph yet the projections were increasing in their 'dire-ness'. It was at this point that we turned the cabin heat & seat warmers off plus dropped the speed to 110. This put the projections right at the edge but the rated range was still well over the amount remaining so we thought we'd be ok. About 100km into the 290km trip the projections were trending below our target distance so I dropped the speed to 100, as slow as I dared on Highway 2 without risking an accident, plus we closed the Nav & switched from Internet radio to OTA radio. The rated range was still above the target but we noticed that the trip meter average energy usage was quite a bit different than the 50km projection average usage so we started to get frustrated & distrust all the numbers being shown.

The projections were right around our target distance, sometimes higher, sometimes lower. We made it all the way to the edge of Calgary and with 12km to go the car hit 0 rated range at which point it beeped and displayed a little red "Charge Now" message on the small screen. The orange speed limiter bar was down to around 50. With 7km to go the car displayed a second message stating "Car shutting down. Pull over safely." with the orange speed limiter bar now down to 40. We made it under power for a few hundred more meters to a safe spot & pulled over. The car was still on but after coming to a stop it would no longer move, no big surprise. I put it in Neutral & emptied the bricks out of my underwear before calling Tesla Service who were fantastic & helpful & didn't once mock me for the stupid thing I'd just done. I put the car in 'Jack' mode and tried to put the active suspension to 'Very High' but only the rear of the car lifted, the screen just sat and displayed a little spinning circle from there. I was still able to click on things, the Tesla service guy had me power down the car to wait for a tow. Fun Tesla Fact: the driver's seat has a weight sensor to detect someone sitting there. If you power off the car then stay in the driver's seat, for example if you want to stay out of the cold when waiting for a tow, when you shift your weight around enough the car will turn back on. After 3 or 4 times of this the car starts to display a "12V System Low" message until you remember about the seat sensor & then move to the back. Opening the driver's door, say if you're moving to the back seat, will also turn the car back on. Yelling at the car will not turn the car off, you still have to use the touchscreen. After waiting about 15 minutes while Tesla sorted out a tow I heard a weird click/thunk noise from the back driver's side of the car. I didn't see anything when I got out to look so I just got back in the car. Tesla phoned maybe 10 minutes after to sort out my location, the service guy then said "I forgot to tell you: you need to plug your UMC into the car before the 12V battery dies, once it does the mechanism holding the locking pin for the connector releases & you won't be able to plug it in." That click/thunk? Falling locking pin.

The tow company showed up about 45 minutes from when I'd pulled over, unfortunately they sent a 'regular' tow truck instead of a flatbed despite the Tesla service guy (on the conference call) and myself (the towing company phoned me directly to confirm my location) saying explicitly I needed a flatbed. The tow guy said one wasn't available so I had no choice but to watch him hook up my car. He did put a skate underneath the rear wheels so the car itself was not rolling. As it so happened I pulled off right beside an on ramp that led to a residential area, we were able to travel that way to the hotel instead of down the freeway so for the 6km or so to the hotel the tow never exceeded 50km/hr & the car wasn't bounced around too much. The charger was luckily right by the main entrance so it was easy to get the car positioned to charge. The charger had a J1772 so in the end it was good that I couldn't plug the UMC in. We were able to pull the front noseclip off the car & boost the 12V system, thankfully it didn't take long to get enough power into it to have the locking pin retract & the system turn on again. To further add insult to injury my twin-charger car would only pull 40 amps from the Sun Country CS-90 charger.

 

[Spurkey]

...sorry, I didn't realize the story would get that long. In the end it was my fault, I have nobody to blame but myself. I can't help but be a little mad though at the 'Rated Range' metric which is almost entirely bullshit. The battery graph should tell you the amount of energy remaining, no magic conversion to some arbitrary distance. Same deal with the 'Instant' projection, the distance it gives is useless. It should list the actual specific draw in energy units.

We knew fairly early on that we were drawing too much, I knew that the standard charge stored 80% which at 85*0.8=68kW. We could see that the average Wh/km was 265 on the projection graph & 290 on the trip meter 30 minutes into the trip, it didn't take us much to figure 265 Wh/km * 290km = 76.8kW in the *best* case. We knew we needed to get the usage down to at the very most 230Wh/km, when we dropped the speed to 100km/hr we got down to 210-215Wh/km but we had no idea precisely how much energy was left in the battery. We tried to find alternate charging locations via PlugShare - the 'charger' in Red Deer (about halfway) had 1 review stating 'No actual charger is here, owner has plans to install one eventually'. There was a wall plug at a library in a small town 2/3 the way but it was off the highway, had no reviews and we didn't want to waste energy on something that may not be present or usable.

Yeah I'm a bit upset at the data displayed by the car but that doesn't change the fact I didn't plan appropriately and that's what did me in. For a first-time road trip I should've charged fully so that I could learn how the car behaves and I probably should've located an RV campground halfway before leaving that I could charge at. Mea culpa.

 

[Bearman]

Thanks for sharing and dont be too hard on yourself :smile:
I'm glad things turned out ok and that service was helpful.
Dont be afraid to range charge and have back up plans for charging along the way seems to be the best advice I've found here.

 

[JakeP]

Seriously, the big lesson is don't be afraid to range charge, that is precisely what it is there for. I learned that myself the hard way on my first long trek, a 192-mile trip in temperatures under 20F, where we made it home with 7 miles to spare. Preheating the car from shore power, hypermiling techniques, driving in range mode settings and using seat heaters instead of fan-based climate control...all these help, but they cannot help as much as unless you simply starting out with maximum possible range. Failing that, be prepared to drive slowly and consistently, taking 10 mph off your speed really adds significantly to your range. Of course you now know all this if you have read Doug_G's very instructive posts.

It is very good to know the bit about plugging in the UMC prior to total shutdown, for future cases where people might be hoping for a charge from a AAA truck, thanks for sharing that info!

 

[andrewket]

Thanks for sharing. It is useful to the rest of us.

1. I wonder why the 12V battery dies so fast? Presumably the 12V system was being charged by the larger (400V?) DC system up until you got low. How small is the 12V battery in a MS that it can't power the electronics for at least a few hours?

2. Did you ever figure out why the CS-90 would only provide you with 40A? Perhaps the EVSE model is capable of 90 but it's still being fed by a 50A circuit?

A

 

[dsm363]

Glad you made it safely. A standard charge is actually 90% with no lower end reserve (backup) available to the driver.

 

[Doug_G]

Sorry to hear that... not a great experience. Yeah, you can't depend on Rated Range, especially if the temperature is near freezing. You were so close!!!

Never, ever hesitate to use Range mode. A couple of hours at 100% is nothing - way better for the pack than a couple of hours at 0%! Just don't leave it in Range mode for months.

Just so people don't have to hunt I'll repeat my road trip mantra... Start out slow until you see how your range is doing. Use Range driving mode because it limits HVAC power - enough so that it isn't all that useful to turn the heat off... just slow down 5 kph instead and stay toasty. Always use the seat heaters if cold. Switch the Energy App to Average mode (it always resets itself annoyingly to Instant mode). Preheat the car using the App, or simply charge just before you leave, so the pack is preheated; otherwise the pack heater gobbles range. Expect to knock 20% off Rated in freezing temperatures. Don't worry about the power draw of anything except (a) slow down! and (b) if desperate turn off cabin heat... but it is still more effective to slow down.

 

[mckemie]

...sorry, I didn't realize the story would get that long. In the end it was my fault, I have nobody to blame but myself. I can't help but be a little mad though at the 'Rated Range' metric which is almost entirely bullshit. The battery graph should tell you the amount of energy remaining, no magic conversion to some arbitrary distance. Same deal with the 'Instant' projection, the distance it gives is useless. It should list the actual specific draw in energy units.

We knew fairly early on that we were drawing too much, I knew that the standard charge stored 80% which at 85*0.8=68kW. We could see that the average Wh/km was 265 on the projection graph & 290 on the trip meter 30 minutes into the trip, it didn't take us much to figure 265 Wh/km * 290km = 76.8kW in the *best* case. We knew we needed to get the usage down to at the very most 230Wh/km, when we dropped the speed to 100km/hr we got down to 210-215Wh/km but we had no idea precisely how much energy was left in the battery. We tried to find alternate charging locations via PlugShare - the 'charger' in Red Deer (about halfway) had 1 review stating 'No actual charger is here, owner has plans to install one eventually'. There was a wall plug at a library in a small town 2/3 the way but it was off the highway, had no reviews and we didn't want to waste energy on something that may not be present or usable.

Yeah I'm a bit upset at the data displayed by the car but that doesn't change the fact I didn't plan appropriately and that's what did me in. For a first-time road trip I should've charged fully so that I could learn how the car behaves and I probably should've located an RV campground halfway before leaving that I could charge at. Mea culpa.

I second that. I come from a Leaf which has MUCH poorer "energy in the battery" instrumentation. Still, it would be MUCH better to have at least the option of displaying "kwh left in the battery" in the dash slot where "rated range" is currently displayed.

 

[ToddRLockwood]

I'd be interested to know if your car was running firmware v4.3 because I believe one of the improvements is that the Rated Range algorithm has been improved and takes outside temperature into account.

Tesla service told me that you can minimize the negative impact of a range charge by departing immediately after the charge is completed. When charging overnight, an easy way to accomplish this is to start with a standard charge and then switch to a range charge about an hour prior to leaving.

 

[bonnie]

You did everyone on the forum a service with that post, Spurkey.

I've been concerned over the number of posts along the lines of 'oh hey! you have at least 20 more miles after the battery says it's out'. People need to NOT count on that. Your story is a good reminder. And yes, don't be afraid of charging in Range mode. It shouldn't be a daily habit (that would ultimately harm the battery) - but no sense worrying about range on a distance trip - plus it allows more spirited driving. I typically behave at the beginning of a trip, but when I see I have more than enough to spare, well, EVs are fun to drive!

I've achieved Ideal Range (Roadster version of Rated Range), but it took some work. Between Ideal and Estimated, I have a pretty good idea of what I've got IF I keep driving the same way, with the same conditions (elevation, temp).

 

[mknox]

It is very good to know the bit about plugging in the UMC prior to total shutdown, for future cases where people might be hoping for a charge from a AAA truck, thanks for sharing that info!

That's a good tip for all of us, but I wonder if it would be better to plug the J1772 adapter in rather than the UMC? I would think you're more likely to find J1772 stations in the wild, and I would imagine that the AAA trucks would be equipped with J1772s for the Ford Focuses, Nissan Leafs etc.

 

[dgmanny]

That's a good tip for all of us, but I wonder if it would be better to plug the J1772 adapter in rather than the UMC? I would think you're more likely to find J1772 stations in the wild, and I would imagine that the AAA trucks would be equipped with J1772s for the Ford Focuses, Nissan Leafs etc.

What about just opening the charging door? Would that work or is there an additional interlock?

 

[Doug_G]

What about just opening the charging door? Would that work or is there an additional interlock?

There's a large pin that holds the connector into the socket. Until that releases you can't plug in, even if the door is open.

 

[mknox]

What about just opening the charging door? Would that work or is there an additional interlock?

There's an additional locking mechanism in there to hold the adapter to the car when the car is locked. This is presumably so your expensive UMC or J1772 adapter doesn't get stolen when the car is unattended. It sounds from this thread that 12v power is required to hold the lock open, and when the 12v fails, the locking pin falls into place, and you then can't insert anything into the port. The idea would be to get something plugged in there before this happens, if I'm reading this right.

 

[Mycroft]

It sounds from this thread that 12v power is required to hold the lock open, and when the 12v fails, the locking pin falls into place, and you then can't insert anything into the port. The idea would be to get something plugged in there before this happens, if I'm reading this right.

That's exactly what it sounds like. If so, there are two questions: 1. How did Spurkey know that the 12v battery needed to be "jumped"; and 2. Why isn't Tesla publishing this information for owners?

 

[Rodolfo Paiz]

Tesla only allows the main dash display to show either "ideal" or "rated" miles right now. But those are both hypothetical distances. Tesla really needs to allow the driver to show "projected" range (based on the average consumption in the last X miles) in the main dash display. That's the only range estimate my Roadster could display, and it was always bloody accurate. I never had to think about variables... if the Roadster says it can get there, then it'll get there as long as conditions or driving methods don't change. I miss projected range very much, and I want it back.

(And no, having projected range displayed on the energy app is not as useful for daily life. It's a band-aid, but not a solution.)

 

[Doug_G]

Really it should show both Rated and Projected. Rated is useful as an indication of how full the pack is. Projected is useful on long trips for determining if you're going to make it.

I'd love to see a "reserve" display, which is the difference between your GPS reported distance to go and your Projected range. When driving long distances I'm constantly doing that subtraction in my head. I drive to maintain my minimum safety buffer (30 km).

 

[dsm363]

Exactly. Even a '-12 miles' under the rated which would indicate delta between rated and projected or the distance to destination would be helped. You could adjust your speed until you saw the gap start to decrease.

 

[andrewket]

There's an additional locking mechanism in there to hold the adapter to the car when the car is locked. This is presumably so your expensive UMC or J1772 adapter doesn't get stolen when the car is unattended. It sounds from this thread that 12v power is required to hold the lock open, and when the 12v fails, the locking pin falls into place, and you then can't insert anything into the port. The idea would be to get something plugged in there before this happens, if I'm reading this right.

If the 12V system is sufficiently dead that the locking pin falls into place, doesn't that also mean the electronics required to begin charging are also down? In other words, even if you think to insert the UMC or J1772 into the charge port before the 12V dies, you're still going to need to jump the car to get the electronics up to enable charging, at which point the interlock would release anyway.

 

[ChadS]

Sorry to hear, Spurkey.

As you noted, you could have avoided this if you had spent a lot of times on the forums, soaked in a bunch of information, and done some calculations like the ones HERE - but that is more than EV makers should ask of their customers. It looks like you averaged about 65mph in freezing weather. Your consumption would be increased above the Range number by 8% for speed and 21% for temperature. That would still give you 12-13km to spare, but there is also a 1300' elevation gain that would eat about 21km, so I would expect you to fall about 8-9km short of your destination. You report running out at about 7km from your destination.

As you also noted, this would not have happened if your car wasn't displaying an unrealistic range number on the dash. That number only works in 70-degree weather with no elevation gain at 60mph. Tesla (and all other EV manufacturers) that want to avoid having this happen to their customers could do something like this (which has been mentioned HERE before):

1. Take all of these range factors - speed, temperature, road conditions, elevation gain, wind, etc - in to account and display the expected range for the trip, perhaps with a confidence level
2. If that is unattainable, display a range that is at best realistic, and often pessimistic. I recommend 2/3 of EPA range, which would have been 256km in your case and clearly indicated that you could not make the trip
3. If they don't like showing a pessimistic number, then don't show any range number at all. Just show % SOC, or the kWh left in the pack. Sure customers would not feel comforted when they first sit in the car, but that's a good thing when it's a false comfort. Without a range meter to guide them, they would be overly cautious.

Making Projected range more prominent helps in some cases - those where conditions are similar for the whole trip. But when there are sudden elevation, temperature or speed changes, it can make things worse as it fluctuates wildly.