juliusa
Active Member
The car navigator told you to leave the current charger with 5% estimated range remaining upon reaching the next charger or destination??
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Range Failure
- Thread starter gnuarm
- Start date
Is he, or is he implying that when he said "use the trip planner" he meant "follow its directions"? I mean, it's been a while since I've used it, but I THINK the trip planner function includes suggestions on when to continue you trip.
People seem to be willfully ignoring how this played out. When he got to a Supercharger that was farther along the route, the target arrival estimate was 12%. It was "following the Trip Planner's directions", because it would not suggest needing to stop at that Supercharger when there is already a 12% margin.
Actually, if you pay attention to usernames as you review this thread, you will notice that I have pointed this out several times (and most of those times, you have hit like). However, if you follow the quotes back on what I just responded to, and assuming my memory is serving me correctly, gnuarm complained about not having a good tool, and tes-s pointed out a tool gnuarm might not be using (Trip Planner). The point of my response to gnuarm here was that using navigation while making your own decisions (as he at least fairly reasonably did) and strictly following trip planner's advice are not the same thing.
You implied that he did not follow the Trip Planner's directions, but it did not recommend him to stop there for charging. That's following its directions.
Tes-s implied that he didn't follow its directions, but I see your point. While he explicitly didn't at the start of the story, implicitly following them later on negates that point regardless of whether or not the previous behavior would have made a difference and perhaps even implies a problem with Trip Planner, making the title of the thread even more accurate.
juliusa
Active Member
In what way?
Are you using the Tesla Trip Planner feature (and following its guidance), or are you making your own charging decisions? It guides you to your destination via superchargers as necessary - including telling you when you have sufficient charge to leave the current charger and reach your destination.
So let's be very careful about exactly what the facts are so there is no distortion:
1. Did you have Trip Planner turned on?
2. When you left the first charger with 5% estimated range on arrival, did Trip Planner inform you there was sufficient charge to reach the next charger/destination?
3. Did you get any sort of message when your estimated range on arrival at destination dropped below 0%?
My experience has been that when the nav is worried you will not make it to the destination shown in the nav, it gives all sorts of warnings to slow down, and eventually says charging needed to reach destination.
He has implied that the answer to 1 is yes. As outlined above, the answer to 2 is irrelevant, because Trip Planner should have routed to an additional supercharger if necessary. Regarding 3, have you ever been told to slow down to reach your destination when you were going 35 mph? I believe he has already implied that he did not, but I'm not confident he should have. I've seen "drive 45 mph to reach your destination" once, but nothing lower than that. I'm not sure how low the estimated range at destination has to be before you got those warnings, but I'm pretty sure that it's below 10%, in which case, nothing before the point when it was estimating 12% is really relevant. I think the only legitimate question that might not already be implicitly or explicitly answered is, "did you ignore directions leading you to another supercharger?"
One conclusion here is that for whatever reason the energy consumption estimation is inaccurate for this "secondary roads" section of the trip and the difference is about 3% of battery capacity.
For the larger drop on your initial trip I have a theory which is just a wild guess:
In another thread you mentioned that the car got a software update recently.
I assume this update has affected the BMS and there is a chance that the "current total battery capacity" value got somehow reset to a default value (maybe the capacity of a new battery) or the new software version has different curves for estimating the total battery capacity.
The total battery capacity measurement gets more and more accurate as the SoC drops further and further. Saying it in a different way estimating the battery capacity based on a 90% to 60% discharge has a larger error than estimating the battery capacity based on a 90% to 30% discharge.
So at the start of the trip your car thought you have 100% capacity. In the first part of the trip since the SoC was still higher the estimator didn't see any deviation from its original thought. But once the car reached lower SoC the BMS realized the difference and modified the "total battery capacity" value to something like 93%. And modified the range estimation accordingly. Plus there was a loss of additional 3% due to the energy consumption estimation error for the secondary roads.
On your second trip the car already had the updated "total battery capacity", so you didn't experience similar issues.
juliusa
Active Member
Lots of implications. Looking for some direct answers so there is no guessing or "distortions".
Even if the car did tell me to slow down to reach the destination, I was already on slow roads and not driving fast at all. How slow can you go? There are laws limiting how slow you can drive and I already mentioned that on one stretch the speed limit was at least 45, the car wouldn't let me drive faster than 40 on auto pilot and that created a back up even though I otherwise barely saw cars in either direction. It seems traffic ignores the 45 speed limit and drives 55 here.
I also mentioned that at one point the car did instruct me to turn around and head back to the highway where the last Supercharger was. But I don't have a reason to believe I would have made that destination either with the way the range was continually dropping. I knew there should be level 2 charging within range. The only question was which route to take. I decided to take the most conservative route and head for the nearest L2 chargers.
This issue was not consistent. The return trip only saw a 2% drop in range over the same roads. Prior trips didn't produce any noticeable drop in range... I think. Thinking back, the very first time I drove this way I had missed my first turn off the highway and ended up running on fumes reaching the Supercharger. I didn't give it much thought at the time since I knew so little about what to expect from the car. But I've been back this way at least one other time and maybe two where I noticed nothing unusual.
I suppose anything is possible. The car wants to do another update. Not that we will know what the update actually provides. A bit like flying a 737 MAX 8.
juliusa
Active Member
1. Did you have Trip Planner turned on?
2. When you left the first charger with 5% estimated range on arrival, did Trip Planner inform you there was sufficient charge to reach the next charger/destination?
3. Did you get any sort of message when your estimated range on arrival at destination dropped below 0%?
2. When you left the first charger with 5% estimated range on arrival, did Trip Planner inform you there was sufficient charge to reach the next charger/destination?
3. Did you get any sort of message when your estimated range on arrival at destination dropped below 0%?
juliusa
Active Member
Exactly!! Some can, and some can't. Just ask the Lion Air crew and third pilot that was in the cockpit. Not the crew that crashed - the crew that flew it the day before.
BrokerDon
Active Member
I actually read every post on this thread and driven our 2015 P85D 45,000 miles without experience the extreme "range anxiety" the OP has repeatedly tried to justify. Seems like a "PEBCASW" problem to me (similar to PEBCAK - Wiktionary)
Your point is valid I suppose. When I left Rocky Mount it said I should stop at one of the two remaining Superchargers along the highway. I don't recall which one. To get an estimate for the final destination you have to turn off the charging recommendations. Once I did that it said I would reach my destination with 5%. After driving some time the estimate rose until it was at 12% prior to reaching either of the two Supercharger stations. The last station was about 7 miles from where I turned off Rt 95 onto another highway. I don't recall the distance on that highway, but it was maybe 10 or 20 miles. Still at 12% I continued on the back roads. Again, I don't recall the exact distance, but I think it was about 70 miles to my destination and 60 miles to the Supercharger I intended to stop at.
This was the point where the estimate started to drop. It didn't worry me at first since there was so much available reserve. 12% is about 36 miles which is more than half the distance I had yet to drive!
I think I've gone over the remaining details before in sufficient clarity. I continued to monitor the remaining charge carefully and changed my destination more than once to see what reserve I would have at the various charging point. Initially when I set a new destination it would give a low number but it would rise as I drove. After traveling further it stopped rising. At one point the navigator did tell me to turn around and head back to Rt 95 to reach that Supercharger. I reached a decision point where I gave up on any of the coastal destinations and had to take a different route to Conway which was the closest of any charging.
My concern is two points. Obviously I don't get why the remaining charge estimate would alter so drastically when nothing changed with the inputs. There was nothing about the route that the navigator (trip planner) didn't know about at the start. The other issue is why the trip planner would be so pessimistic at the outset of each of these and then improve it's estimate? What inputs could be changing that the tool needs to change it's estimate?
I typically don't follow the trip planner's recommendations to the letter because it will have me stop twice as often for half as long. On my trips I prefer to drive at least 200 miles on a leg then stop for a meal with a full hour of charging. I don't see any utility in stopping for 20 minutes, then stopping again for 30 minutes when I am going to eat and take an hour on the second stop and possibly be required to leave the restaurant in the middle of my meal to disconnect from the charger! Then there is the issue of finding a place with decent food. Many of the Superchargers are at gas stations with nothing else around. Who wants to eat at a Sheetz???
So on the dozens of trips I have taken, I turn off the charging suggestions to see my expected charge at the station where I want to stop. This is nearly always on highway where my range has been consistent and so I roll into a station with 12% to 20% left. In this one case (I've driven this route more than once) I saw the estimate plummet and often when I tried to explore an option it would give an initially poor estimate only to improve it as I drove.
Now I know that when traveling off the highway I need to allow another 10% on my final range estimate. The irony is that I always get so much better consumption figures on slower secondary roads. I can't understand why the car mucks up the estimate so badly.
juliusa
Active Member
So Trip Planner told you to stop at a supercharger along the way, you decided not to, and this is a "Range Failure"??
He said it told him to turn around. If that means it was directing him past or away from the supercharger and changed its mind, then it would be even more of a failure. However, multiple trips have been discussed, some of which involve taking an alternative route, so I'm not going to re-read all 5 threads to confirm whether or not that is possibly what happened.
@gnuarm as I typed the above, I thought of a logical explanation that could apply. If you did choose an alternate route and expected it to tell you to turn around for a short period of time before rerouting you the way you intended to go, is it possible that the 12% estimate you saw was for that supercharger and not your final destination? I know you say you turned the charging recommendations off to see charge at destination, but I assume you must have turned them back on in order to be told to turn around to charge. In that scenario, as you continued to get further from it, the estimate would drop quickly, because for each mile further you went, another mile would be required to get back. This doesn't necessarily make sense given your other experiences on this same route, but is it possible some atypical estimated range loss occurred on the highway and the route changed before you ever got to the surface roads or the navigation didn't reroute and you were still seeing an estimation to the supercharger vs your final destination?
You don't seem to understand his concerns.
You are ~65miles from destination. Car tells you you will get there with 12% remaining. There are no known reasons why the consumption would be higher than estimated. Yet you don't reach your destination. Explain this.
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