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Old 04-15-2018, 09:44 PM   #65
JST
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Join Date: Oct 2003
Posts: 24,593
Quote:
Originally Posted by TD View Post
So...

I’ve now taken the car on a couple of road trips and I’m officially annoyed with the trip/supercharger planning built in to the NAV. It assumes you are going to drive like a grandmother.

I headed out this afternoon heading home to DC from Ithaca NY. I left with about a 90% charge, ~230 miles showing on the range.

It had me head in to Binghamton NY to hit the supercharger there. I was supposed to get 30 min of charge there and then go to Harrisburg PA for another 20 min charge. I was to get home with about 15% of battery.

I arrived at Binghamton with about 190 miles of range. After about 35 min, it throttled back my charging after telling me I had enough charge to resume my trip. I spent another 10 min adding more charge but at a significantly reduced charging rate. Finally I gave up and got on the road.

Within 10 min, it was advising me to keep it under 70 mph if I wanted to make it to my destination. It was showing I’d be at 5% of battery at Harrisburg. Clearly it didn’t factor in either my driving style or the fact that this portion of the trip was almost entirely in mountains.

That’s too much anxiety for me so I turned off the routing and had Waze route me to the supercharger in Scranton. I’m here having dinner now and topping off. I’ll probably still need to add 10-15 min of charge in Harrisburg but I won’t be at risk of coming up short.

Still, I am pissed at the planning functionality. Know that I don’t drive 65 and that this is a series of climbs, there was no way it was going to make the 197 miles from the Binghamton SC to the Harrisburg SC on a stated range of 220 mi (what I left Binghamton with). Now I’m stuck making three stops on a trip that would be 5:30 in an ICE vehicle.

I’m not annoyed with the overall Tesla road trip limitation, just with the trip planning. If it would have let me get a full charge in Binghamton, I would not have had to stop until Harrisburg. It should have been able to figure out that I needed it. And it should not throttle my charge rate if I decide I need more juice, especially with only 1 charger out of 8 occupied.

Matt and Josh, how do you guys deal with this? I’m thinking I’ll have to just do my own planning and not put my destination in the system. I have it charging now without a route loaded and it’s not throttling it back - just charging away.

I hate it when things that try to be too smart end up being maddening as a result. Working around “features” like this really negatively impact the experience.

TD--

Sorry, that sucks. The Tesla trip planning software is decent, but I've found that it works better if I do the planning on my own. It simply doesn't take into account as many variables as it should. As you probably know, "rated" range is calculated at about 300 kwH/mi, so if you're using more than that you need to adjust your range expectations accordingly. There are websites that help plan for stuff like this, if you want to geek out about it. For example: https://evtripplanner.com/


That said, I've never run into a situation where the Supercharger throttled my charge based on it thinking I had enough juice to reach my destination. I haven't kept up with the most recent software revisions, but I don't *think* it works that way. At least it didn't used to.

What does happen, and what you may have run into, is that Superchargers will throttle back as you get closer to the full capacity of the battery. So it will charge very quickly to 80 percent or so and then start slowing down. The final 5-10 percent of charge takes forever. If you arrived with 190 miles of range, you were already near 80 percent of battery capacity when you plugged in. It doesn't surprise me that after 30 min or so it throttled way back--it would have done that no matter what your destination was. That's just the physics of the battery.

Because of this, stopping three times can actually be faster than stopping twice. If you're charging a battery at a lower state of charge it will charge faster than one at a higher state of charge. The 10 to 15 min charge from 20 percent will add a lot more range than an additional 10 to 15 min from 80 percent.
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