In Car Nav Messed Up

[AcuraDude]

I used to be a fan of the in car nav. In 2021, I traveled over 600 miles each way from KC to Longmont, CO, and the nav was spot on. My car is a 2018 Model 3 Dual Motor Long range with 18” wheels w/out aeros. My average speed was 84mph in both directions.

Fast forward to last weekend when I was making the same KC to CO trip again. I was charging in Russell, KS and after ~15min, it said I had enough charge to make it to Colby, KS. I thought the charge was oddly quick, and the arrival SOC was 26%. That is plenty for me as I try to go ‘Out of Spec’ style and arrive with a 10% SOC to maximize charging. About 1/2hr west of Hays, KS, the nav tried to reroute me back to Hays SC. Being about 50mi outside of Colby, I thought I’d try and make it, so I forged ahead. I slowed down to 65, then 55, then 52mph. That was extremely dangerous as the speed limit is 75mph. Fortunately, it was during the day and my hazards were on and I hugged the shoulder. After 1hr of driving like this with no ac in 85deg weather, I rolled in to Colby with 1mi remaining. It is not a good feeling when your miles of range remaining drops faster than your distance to destination!

Several times, both the in car nav and my phone app would say I had enough charge to get to my destination. However, after clicking ok, the arrival SOC read as -8%. Other times the nav wanted me to charge to 100% and skip multiple SC’s. I of course cancelled that.

I did a reset while in CO but that did not help, and weather wise I do not believe it was significantly different than 2Yrs ago. When I overrode the nav planner, my arrival SOC seemed to be pretty accurate.

 

[Soul Surfer]

Yikes! I’ve never trusted the “you’ve got enough to get there” messaging. I tend to always add an additional 10-20% more just to be safe.

 

[LoudMusic]

I've seen weird behavior like that as well. It's a good idea to do your own math. For interstate cruising in my Model Y I tend to estimate 2 miles per percent. To go a step further if I cancel the route and specify the next Supercharger it typically gives a more accurate estimation.

 

[AcuraDude]

Yes good suggestions. After my first trip was so successful, I became too reliant on the in car nav. On future road trips I will do more pre planning, key in my own charging stops, and add a 10% buffer after the 'you have enough charge to continue' message appears.

 

[RTPEV]

Yeah, that stinks...I think I've seen that happen as well, but I can't recall the circumstances that cause it. It's kind of like it temporarily forgot where it was or something.

I usually use ABRP as my primary planner while on a trip. It does a better job (for me anyway) of predicting charge times, whereas the car would have me stay 5-10 minutes longer than necessary (although I must say, the car has gotten much better recently).

My work flow is like this: I'll fire up ABRP and have it plot the full trip. If I like its choice of the next charge stop, I'll navigate directly to that Supercharger in the car (I much prefer the car for actual navigation, and I can keep tabs on my energy progress using the Energy Trip graph). Just before I stop, I look at ABRP's estimated time to charge and target SOC, and then plug in and take a break. The reason I make sure I look at ABRP beforehand is that when I get back into the app, many times it doesn't realize I'm still charging (I really wish it did) and assumes that I'm unplugged and already traveling to the next stop, which now it will recalculate as being closer than it needs to (because I'm still charging). Once I reach the target SOC %, I'll unplug and repeat the process for the next leg.

If at any time I see a huge discrepancy between ABRP's and the car's predicted arrival SOC, I'll try to figure out why. I do this BEFORE I leave the Supercharger. If something doesn't make sense, I want to figure it out then.

 

[Gasaraki]

I've never had that happen but sometimes rebooting the car while driving with the NAV set will reset the remaining battery guesstimate.

 

[AcuraDude]

Here is a pic after I clicked Ok when the 'Enough charge to continue' message popped up. In the upper left corner, you can see it says I can go, but at the bottom of the nav, on this leg it had me finishing at -4%.

I'll definitely be using ABRP and the other suggestions above.

 

[Chisale]

I do quite of traveling as well and I'd say that approximately 90% it is spot on and works great. But, yes, every once in a while it will wig out like that and miscalculate. And it also goes the other way sometimes too. Says you need another supercharger stop when you know good and well that you can make it. Then you need to reset the Nav and sometimes after starting over then it will figure out that the stop isn't needed. For the other way, I'm like Soul Surfer above. I add at least 10% to what it says it thinks I need and if it adds a little time then so be it.