Odd supercharger routing and -10% arrival on recent trip.

[djtaylor]

Okay sorry this is a little long. My wife’s just taken a trip from the north-west down to High Wycombe for the weekend. This is the first reasonable longer distance using superchargers we’ve travelled (MYLR). Although it’s still only 200 miles (normally trips are 140 miles and regularly executed consuming approx 50% give or take 5%). I Charged to 100% before she left and this got her all the way with 24% left. Reasonable but higher consumption than usual. There was no convenient charging at the destination so the car was parked up for a few nights. Initially made the mistake of leaving Sentry on and within 12 hours got a warning that it turned off because the battery got down to 20%. Returning to the car today it was down to 18%, a quick schedule of a trip home on the app suggested a stop in at Oxford services (18miles away) and then a further stop at Warrington for five minutes (why not just an extra 5 at Oxford?). This was then sent to the car. When the time came to select the sent route in the car and drive off (10min), it changed the routing to Uxbridge supercharger which was well out of the way, similar distance to Oxford? Leaving Uxbridge charger (which cost a £2 car park charge) once enough to resume the trip was on board it then decided to route to Warrington with an arrival charge of -10%. She didn’t notice and carried on with the journey, It was just lucky that I decided to check on the app where she was up to. I noticed an arrival at -10% the car was happily cruising up the M40 with a -10% arrival on the screen. I had to call her and get her to cancel the Nav on the fly then restart it, it then scheduled another stop at Hilton Park (10% remaining).

My points on all this:

1. When you arrive there is no guarantee you’ll have enough after a few nights to get to a decent fast charger. The Nav appears to aim to get you to the destination, if that’s with 5% left it’s up to you to check there’s a charger nearby.
2. The route you build on the phone app isn’t what you necessarily get, and it’s happy to send you 20 min out of your way (40 min round trip) to a pay car park. Even though there are 16 SC’s the same distance in your direction of travel- not great!
3. Appreciating that the aim is to get enough on board and then move on. It’s still doesn’t really seem sensible to make multiple stops to charge when the journey is only 200 miles and the range is supposed to be 300+. The full journey shouldn’t take more than 80%, although the trip down suggested pretty average economy.
4. All in all a bit of a mess really and confidence damaging for my wife. You really can’t just plumb in your destination and expect the car to work it all out. You need to put a lot of thought round it to make sure you’re not going to get stranded.
5. You need to sense check that it’s made its calculations correctly. The car was quite happy with a -10% arrival.

Not the seamless experience I expected.

1. All in all a bit of a mess really and confidence damaging for my wife. You really can’t just plumb in your destination and expect the car to work it all out. You need to put a lot of thought round it to make sure you’re not going to get stranded.

Not the seamless experience I expected.

One of the things that you'll see several asking for here and it's also my request is "Arrive with xx %" but to offer a tip that might help while you adjust and that's to not just consider the route as start to end but plot the round trip or at least next supercharger after destination.
Example:-
You want to from home (lets say Leicester) to Glasgow. If you plot that, then you'll end up ariving at Glasgow with ~13%.
For your trip, set your destination as home and then edit the trip to add Truro, then move it up in the trip planner such that your trip is
Leicester -> Glasgow -> Leicester.

By doing this, upon arrival at Glasgow, the car will have sufficient charge to route back to the next supercharger on the way home. If you're going to have sentry enabled or drive around a bit, then at the last charger before Glasgow, add appropriate % more.

e.g. (not the best example because it hasn't actually changed the plan upon arrival but illustrating the home-destination-home idea.

When i'm on a Euro trip, i'll send the entire route to the car but along the way it gets modified quite heavily, mostly destination+next and a bit.

 

[MB11]

Well I've never seen that in the 5 years I've been driving Tesla, or read anyone else on here ever detail a similar experience where it takes you the opposite direction to the way you are heading. Nearest I've seen was heading back from Wales on the M4 heading up the M5 expecting to charge at Michaelwood, but it decided it was busy so routed me to Cribbs, but that's only a small detour.

There will be a reason, and that will have been viewable in the car, perhaps Oxford was temporarily closed but seems unlikely or there could have been delays on the M40/M42 so it was quicker to go M25/M1/M6, but by the time she was charged the delays had gone, or switched.

The navigation doesn't make wildly wrong decisions.

It went from HW to Uxbridge to charge then back up the M40 past HW and Oxford -M5-M6-M56. No idea why it did this, i wasn’t in the car, but I did watch it happen on my phone app. Unfortunately the app only shows the current leg of the journey in progress so it was impossible to validate everything. I like the workaround of routing it to somewhere a bit beyond your destination, to ensure it arrives with some spare. I’m likely to do this in future if I don’t know I’m landing where there’s a fast charger near.

 

[djtaylor]

It went from HW to Uxbridge to charge then back up the M40 past HW and Oxford -M5-M6-M56. I like the workaround of routing it to somewhere a bit beyond your destination, to ensure it arrives with some spare.

The other neat thing of course is that even if not in the car, you can "help" the driver by setting a route in the app and sending to car. I went out the other day to drop a car off with my wife following in the Tesla. She's not a confident "follower" and said the usual "don't leave me behind" etc.
What I had forgotten was that i'd set the location in my Google calendar which was sync'd in the car and it set that as a desination for her too, simple things but sometimes stuff works out well
I do think that the assumption that you'll always arrive at a charger so low SoC arrival is fine is a bit short sighted though but it is what it is. We ask but instead get a new fart sound or something.

 

[init6]

Am I missing something? If you think 10% charge on arrival is too low, then just sit on the charger for a bit longer - that's what I (and my wife) do.
Seems people want the car to do all the thinking for them.

 

[btc1k]

It's a frequent complaint on here that tesla routing charges "too long" at superchargers and people find they arrive at their destinations with excess SoC (which presumably most don't want as they have destination charging available). Important presumably because of the difference between destination charging (home/friends), or at an SC.

But yes, simple solution to not arrive with 10%, is just to stay longer at the supercharger to add whatever excess you need to arrive with.

 

[ringi]

It’s simply wrong for sat nav routing to think, and thus factor in, that unclassified roads are 60mph

Lively to be correct for areas of USA with high sales and we are not important compared to USA .

 

[Tony Hoyle]

As I'm leaving town there's a nice road, not too busy. There's also a farm track, which branches off the main road then comes back to it about 100 yards further on.

100% of the time tesla tells me to navigate down the farm track, presumably on the theory that it's 'faster'.

 

[Adopado]

Lively to be correct for areas of USA with high sales and we are not important compared to USA .

Fortunately that's not actually how the nav normally works (despite what @MrBadger posted). I've no doubt it may misjudge the likely average speed on some roads but that's not routinely the case. I say this because I drive on 60 limit country roads 90% of the time. These are roads where you are going to average only 45mph yet the nav correctly predicts my arrival time, so it knew I wasn't going to be doing 60mph. I suppose there is a possibility that it operates completely differently when doing a re-route off the motorway but I can't think why it would.

 

[WannabeOwner]

Some thoughts:

When you arrive there is no guarantee you’ll have enough after a few nights to get to a decent fast charger

If predicted arrival at destination is showing, say, 10% and you want more (e.g. to allow for "Tomorrows onward trip") then over-charge at your last Supercharger stop:

With the destination set in your SatNav use the TRIP TAB on the Consumption graph. The graph will change to show "predicted arrival percentage" as you charge, and you can wait until you have "enough % prediction at arrival" before you set off.

Or put an extra destination in your SatNav (i.e. AFTER your actual destination, for the night, for where you want to go next - e.g. HOME or a Supercharger en route for "tomorrow")

The route you build on the phone app isn’t what you necessarily get, and it’s happy to send you 20 min out of your way

Like @GRiLLA I've never seen that (I've done around 200K miles in Teslas, and TeslaFi says I have used Superchargers more than 150 times)

However, I have had my destination Supercharger go off line (SatNav showed a message that there was a power cut there) and it re-routed me elsewhere.

Traffic / weather / etc. will alter the time that the original route will take and thereby actual consumption, so SatNav may choose a different route based on a variety of factors.

Appreciating that the aim is to get enough on board and then move on

A number of reasons for that:

Car charges fastest 0-70%, 70-80% is OK, above that is "dog slow". (Maybe your multiple stop SatNav route never got to 70% on any leg, but if any of that would have been more than that then that might be the reason).

Also the first stop Supercharger may be a crappy V2 where, if someone parks next to you, then the two of you will share the available power. That will be slow. If there is a V3 / V4 250kW charger further up your route it would make much more sense to only stop at the first one for the minimum you need to get to the next, much faster one

But ... there is always the risk that the next one will be busy by the time you get there, or you get a torrential thunderstorm in Summer massively sapping your range, etc. etc. So you might choose to linger at the first one.

Also, "best" is to charge as near to your destination as possible, and not as near to start of your journey. You may be held up in traffic / roadworks, and use much less fuel than expected (or encounter rain / thunderstorm / snow and use MORE). The nearer you are to destination the better the prediction will be of how much you need to reach the destination and that will benefit your time and pocket (cost of public charging vs. home charging). So short-stop at first, and "whatever needed" at the final stop is best strategy (to reduce total amount of, usually expensive, public charging) ... blended with how fast the various chargers en route are.

All in all a bit of a mess really and confidence damaging for my wife

Understood. My wife similar. On more "challenging" trips I summarise details from ABetterRoutePlanner for her. And that started back in 2015 when Superchargers were scarce, there was no back up plan possible, and 3rd party charging was absolutely diabolical (rather than just plain diabolical as it is today)

I’d rather be able to set the % on arrival so I can cover for an unfamiliar location

ABetterRoutePlanner will let you do that. It has a myriad of options you can fiddle with. Adding that sort of flexibly into the car SatNav is a balance (for Tesla) between Comprehensive and Complexity for the user

 

[WannabeOwner]

100% of the time tesla tells me to navigate down the farm track, presumably on the theory that it's 'faster'.

I presume that is based on the 3rd party map data that Tesla buys in and may very well be, wrongly, indicating that its a perfectly fine route (and shorter)

 

[MrBadger]

Fortunately that's not actually how the nav normally works (despite what @MrBadger posted).

Some definitely do and even expose the speeds to the user.

I’m not saying that it will use the speed limit as the target speed for a particular road, but some definitely use the same target speed for the same type of road.

I think it was my old NavMan unit that even allowed you to adjust the target speed for a particular road type. Off top of my head, default target speed for motorways was 60 (vs 70), single carriageway A roads was 50 (vs 60), an unclassified roads was 40 and not 60 or, in the case of many, 20 or less as a practical safe speed.

Doesn’t take much for an unclassified road with target speed of 40 to be on paper quicker than an A road with target speed of 50 before taking into account mild congestion- even if the practical speed for that road is averaging 20 or even less - I’ve been rerouted more than several times on a detour up a 6’6” road with passing places and have met oncoming traffic so ground to a complete stop whilst cars pick their way between bushes on one side and other cars mirrors on the other only to pop out at a nicely flowing A road that happened to be a couple of miles longer/couple more junctions than the magical mystery cross country tour.

As I say, it’s not just Tesla, but some sat nav’s are more transparent than others over their routing preferences.

 

[Kansalis]

I think Tesla just uses the Google Maps routing and speed estimations doesn't it? I know there are now added calculations for efficiency and arrival SoC but the routing is all Google I believe. I haven't done it for a while, but I did compare the Tesla route to Google a couple of times when I first got the car, and found the routes and arrival times almost identical.

I've always found the arrival times estimated at the beginning of a drive are very very close to reality, unless something drastic like an accident happens en route. The Google crowd-sourced traffic and road speed data is pretty impressive most of the time. It certainly seems to take into account real world speeds on national speed limit roads, in my experience.

 

[WannabeOwner]

some sat nav’s are more transparent than others over their routing preferences.

I would have expected Tesla to capture segment-times actually driven by users, drop the top / bottom 10% (or whatever) and then adjust the Map Data for those times

Maybe that's pants though ... seems to me that Waze uses segment-times based on time of day / day of week (i.e. hopeless for Monday morning rush-hour on a bank holiday Monday)

 

[Rob_S]

Just don’t trust it fully. I have found that since I dropped premium connectivity routing is less consistent.
Same route to work each week and I now get a very different way into Edinburgh each time. Previously it kept me on the same route.
Odd huh? Have taken to ignoring it telling me to go various wacky ways as it gets the ETA completely wrong and made me late each time I followed it blindly
I am going to bump the ‘route to save 10 mins’ option up a bit, or remove it, perhaps an update has coincidentally broken it.

 

[MrBadger]

I would have expected Tesla to capture segment-times actually driven by users, drop the top / bottom 10% (or whatever) and then adjust the Map Data for those times

Maybe that's pants though ... seems to me that Waze uses segment-times based on time of day / day of week (i.e. hopeless for Monday morning rush-hour on a bank holiday Monday)

You and @Adopado are right. I was thinking non live traffic sat nav’s - world has moved on from my NavMan and my other sat nav the live traffic is a subscription that I no longer subscribe to.

Would like to know what level of granularity are used though for segments and if it’s consistently applied for all roads at all times or just some as that would explain the very real magical mystery tours that take place up totally inappropriate unclassified roads.

As for Monday morning/bank holiday etc we simulated various roads around a fairly large midlands city and as a result comparison (we were simulating effects of various air quality mitigations) we used 14 baselines that could affect the simulation - the actual simulation software that we used (a partner in the project but not something we had influence over core functionality over) used 12 scenarios. I wish I could remember what the 14 were, but they did include differences for Mondays, bank holiday Mondays, Christmas mid week, Christmas weekend etc.

I suspect that Google et al have a similar baseline for different days (and times) then apply an average traffic weighting to get a better approximation for what it is seeing (I suspect around 15 minute delay). Tesla fleet speed may also be used for some values but I have never read anything to say that Tesla fleet real time traffic speeds are ever uploaded.

 

[WannabeOwner]

Tesla fleet speed may also be used for some values but I have never read anything to say that Tesla fleet real time traffic speeds are ever uploaded.

now I think about it, probably easier [i.e. for Tesla] to rely on Google Map Data (inc. traffic state)

we simulated various roads around a fairly large midlands city and as a result comparison (we were simulating effects of various air quality mitigations) we used 14 baselines that could affect the simulation

I used to work with a guy who had, previously, worked on linked traffic light sequencing (back in the '70s). I was curious how they tested changes to their algorithm:

"We went out on bikes at rush hour and saw how badly the traffic backed up" !!

 

[MB11]

Some thoughts:



If predicted arrival at destination is showing, say, 10% and you want more (e.g. to allow for "Tomorrows onward trip") then over-charge at your last Supercharger stop:

With the destination set in your SatNav use the TRIP TAB on the Consumption graph. The graph will change to show "predicted arrival percentage" as you charge, and you can wait until you have "enough % prediction at arrival" before you set off.

Or put an extra destination in your SatNav (i.e. AFTER your actual destination, for the night, for where you want to go next - e.g. HOME or a Supercharger en route for "tomorrow")



Like @GRiLLA I've never seen that (I've done around 200K miles in Teslas, and TeslaFi says I have used Superchargers more than 150 times)

However, I have had my destination Supercharger go off line (SatNav showed a message that there was a power cut there) and it re-routed me elsewhere.

Traffic / weather / etc. will alter the time that the original route will take and thereby actual consumption, so SatNav may choose a different route based on a variety of factors.



A number of reasons for that:

Car charges fastest 0-70%, 70-80% is OK, above that is "dog slow". (Maybe your multiple stop SatNav route never got to 70% on any leg, but if any of that would have been more than that then that might be the reason).

Also the first stop Supercharger may be a crappy V2 where, if someone parks next to you, then the two of you will share the available power. That will be slow. If there is a V3 / V4 250kW charger further up your route it would make much more sense to only stop at the first one for the minimum you need to get to the next, much faster one

But ... there is always the risk that the next one will be busy by the time you get there, or you get a torrential thunderstorm in Summer massively sapping your range, etc. etc. So you might choose to linger at the first one.

Also, "best" is to charge as near to your destination as possible, and not as near to start of your journey. You may be held up in traffic / roadworks, and use much less fuel than expected (or encounter rain / thunderstorm / snow and use MORE). The nearer you are to destination the better the prediction will be of how much you need to reach the destination and that will benefit your time and pocket (cost of public charging vs. home charging). So short-stop at first, and "whatever needed" at the final stop is best strategy (to reduce total amount of, usually expensive, public charging) ... blended with how fast the various chargers en route are.



Understood. My wife similar. On more "challenging" trips I summarise details from ABetterRoutePlanner for her. And that started back in 2015 when Superchargers were scarce, there was no back up plan possible, and 3rd party charging was absolutely diabolical (rather than just plain diabolical as it is today)



ABetterRoutePlanner will let you do that. It has a myriad of options you can fiddle with. Adding that sort of flexibly into the car SatNav is a balance (for Tesla) between Comprehensive and Complexity for the user

All great points, love the one about monitoring range on the trip graph, didn’t know that. It was worth the effort to post to get all the great inputs. Many more tools to improve it next time!

 

[djtaylor]

Am I missing something? If you think 10% charge on arrival is too low, then just sit on the charger for a bit longer - that's what I (and my wife) do.
Seems people want the car to do all the thinking for them.

Yes but is there any reason that the car can't do that bit too? We're still dealing with all those for whom this seems difficult, it's all in the anti-EV stuff as to why this is a problem, range anxiety etc.
The car has data for how its efficiency, it would be trivial to ask "how many miles spare would you like at destination?" and just add that to the last charge stop, no reason it can't do that and would take less programmer time than some of the other stuff that gets added, it's even a school level programming problem.

Remember, this was someone's first longer trip, those of us past that anxiety and learning the nuances see it differently perhaps but yes, the car can do this easily but doesn't and so the question when doing that last charge is "how much more should I add?" Same problem, no different than adding an extra gallon or two but easier now since it's all a coupled system.

 

[djtaylor]

All great points, love the one about monitoring range on the trip graph, didn’t know that. It was worth the effort to post to get all the great inputs. Many more tools to improve it next time!

2 or 3 long trips with supercharging is about all it takes, then you'll have lost your anxiety issues and be aiming for arrival home on 1%. I nearly did that once but traffic was slower than planned, too many caravans and I arrived at home with 2%. I felt robbed! Doubly so since the next day was FREE SUPERCHARGER DAY and that night I charged up to 60% only to have a bit of capacity for free day.

 

[ajmorr.is]

Well I've never seen that in the 5 years I've been driving Tesla, or read anyone else on here ever detail a similar experience where it takes you the opposite direction to the way you are heading. Nearest I've seen was heading back from Wales on the M4 heading up the M5 expecting to charge at Michaelwood, but it decided it was busy so routed me to Cribbs, but that's only a small detour.

There will be a reason, and that will have been viewable in the car, perhaps Oxford was temporarily closed but seems unlikely or there could have been delays on the M40/M42 so it was quicker to go M25/M1/M6, but by the time she was charged the delays had gone, or switched.

The navigation doesn't make wildly wrong decisions.

I was dropping someone off in Guildford a few weeks ago, having returned to the UK from a drive to Germany. The SOC in Guildford was 14% and I was heading to Manchester, so definitely needed to charge. Guildford Forum superchargers were 2 miles away and were just off the route north so I fully expected to be taken there for 20 minutes or so (and this is what ABRP was also suggested), with another stop for 10-15 minutes further north - but the car was insistent that I needed to drive nearly 20 miles south west to Liphook superchargers instead, and then back through Guildford to continue the journey. No amount of rerouting would fix this, even adding Guildford superchargers as a waypoint.

I'd say that it's insistence on taking me to Liphook was wildly wrong, so I went straight to Guildford superchargers instead and the rest of the journey went as expected.