navigation and supercharging

[robl45]

two questions, one can I trust the navigation if it says I will have say 10% at destination that I won't run out of juice? Asking because car likes to go to 20% before saying continue and when I'm coming home from say Disney, I don't want to sit and wait.

Second and more important, is there a way to tell the navigation that you don't want to use a certain supercharger? No matter what I did, it kept adding the supercharger I didn't want even though I added two superchargers in that clearly would work.

 

[GtiMart]

The real answer is "it depends". If you drive the speed limit and there'S not too much wind, it might work. The navigation does not work well for me but I know it is reliable for others.
I suggest using ABetterRoutePlanner to see what it calculates. Make sure to enter the advanced parameters properly (wind, speed, road conditions, temperature etc). That is extremely precise. You can play around with it, learn how different conditions change the consumption etc.

 

[robl45]

A better route planner I use for the basic map out. The two superchargers it picked I added to my route, but the navigation had me going to the supercharger it wanted, then back to the first supercharger I put on the map, and then to the next supercharger. Had me getting home like 3 hours later on the screen, it finally figured it out after the first supercharger stop, but it doesn't precondition like that. I had to just change the navigation to the first supercharger so it would precondition.

I also read somewhere (probably here) that Tesla builds in some extra battery much like gas cars do (did?) when you hit empty. Does anyone know if that is accurate?

 

[jjrandorin]

A better route planner I use for the basic map out. The two superchargers it picked I added to my route, but the navigation had me going to the supercharger it wanted, then back to the first supercharger I put on the map, and then to the next supercharger. Had me getting home like 3 hours later on the screen, it finally figured it out after the first supercharger stop, but it doesn't precondition like that. I had to just change the navigation to the first supercharger so it would precondition.

I also read somewhere (probably here) that Tesla builds in some extra battery much like gas cars do (did?) when you hit empty. Does anyone know if that is accurate?

There is a buffer, but you should never (ever) depend on it. You should plan on Zero meaning your car will shut down, simply because if you push it with a gas car, you can have someone bring you some gas. In an EV, you are getting towed somewhere, with a ton of time lost, etc.

As for the first question, "no you can not simply trust it when it says you will get there with 10% left" because you might drive faster than it had computed, there might be traffic, there could be wind, or a number of other things that change how much power you use. Its up to you if you want to push it like that, but "expecting" it to be accurate, when there are that many variables, would be a mistake.

 

[RTPEV]

This of course applies to my driving style and the roads I've driven on, but I've found that the car is somewhat pessimistic (meaning that it will under-predict the arrival SOC, which is a good thing), so if the car says you will arrive with 10%, it will probably be more like 15-20%.

I've found ABRP to be accurate to within 2-3%. I have no hesitation using 10% arrival SOC target on ABRP and trusting it. I usually bring it up on the car's browser, not only to get live updates on my trip progress, but because it puts all kinds of great information front and center, including live stall utilization at your next charging stop.

Regardless of whether you use ABRP or not, you will put yourself at ease by using the car's Trip Energy Graph. That way you can monitor how you are doing versus the car's prediction. Above the line and you are doing well. Below the line, and you may need to adjust your driving style, or perhaps select a closer Supercharger.

The Detailed display is ABRP gives you the same type of graph in a more compact screen that includes much more helpful information:

The actual workflow I use to properly pre-condition the battery is to always just navigate directly to the next Supercharger in the car's nav. If you want to use the car's nav completely, go ahead and plan the trip with it, but if it tries to suggest a Supercharger you don't want to go to, cancel the nav and navigate directly to that Supercharger. Then, once you are there and plugged in, go ahead and re-plan to your destination. But don't let the car override your wishes! Also, make sure you navigate to "such and such Supercharger" and not just the address of the Supercharger. When I use the "share" facility of ABRP to send the charging stop to the car, it only sends the address, and the car doesn't pre-condition the battery.

 

[kavyboy]

I just did a road trip. I was noticing that I was charging way too much and arriving with a lot of "extra" charge at the next supercharger. I was displaying both the Trip Energy Graph and the route planner while charging. The route planner said I would reach the destination at -2% if I unplugged and left, whereas the Trip Energy Graph showed me arriving at +5%. The Trip Energy Graph was more accurate for me. Both were pessimistic, but the charging/routing screens were more so.

I'm on an older firmware version (2020.12.11.5), but this experience may still apply.

 

[EVEnergy]

I've used ABRP and it works but so does Tesla nav and I eventually dropped my subscription to ABRP as I got to know my car. As I supercharge, I watch the destination % on my screen and add 5%-10% buffer to account for wind, temperature, etc. You'll get a feel for what works for you. Using this method, I've never run out and usually arrive with 10%ish left which I'm fine with.

I agree - if you're a min/max'er then ABRP can cut those margins down even more. But honestly, waiting a few extra minutes to get a buffer over what the car says isn't a big deal (even on long trips) and I like the added security.

 

[RTPEV]

As an addendum/clarification to my previous comments about the Trip Energy Graph, it will of course start out with a potentially pessimistic arrival SOC (maybe even negative!) but as you drive (if it is in fact pessimistic) you will see the line shift above the original prediction (gray) line. It doesn't just immediately show you something above the line.

And on the ABRP subject, even though ABRP does have a premium subscription feature, you can still use it for free. I think the only thing the premium gets you is live traffic and live weather. I subscribe to premium simply because I want to support their efforts, but don't hesitate to use the free version if you want to added capability that it gives you (frankly I think it's most valuable feature is having the data I posted a screenshot of available right in the car's browser).