Confused about "Enough Charge to Continue Trip"

[JeffreyC]

We were coming home last night on a fairly short trip - about 150 miles. We started at 30% SOC and I knew we would not have enough charge to complete the trip. I entered our final destination into the Nav and the car routed us to a Supercharger (150KwH) along the route as I expected it would. When we stopped at the SC with about 12% SOC, the car indicated we would need to charge for 25 minutes. This seemed like a long time to me as we only had about 100 miles left. Nevertheless, we waited for the 25 minutes until the car indicated it had enough charge to continue the trip. However, when I checked the Energy graph in the car, it indicated we would arrive at our destination with a 31% SOC, which is much more than we needed. And we did arrive with 31% SOC.

My question is why would the car indicate I needed to charge for so long when I clearly did not need the additional energy? I would have been happy to arrive home with 10% SOC and then charge in my garage overnight. I think we could have charged for 10-15 minutes and made it home with no issues. I know 10 minutes is not much, but it was late at night and the kids needed to get to bed.

 

[TSteve]

Excellent question! On my last long trip the same thing happened to me. Do you know if the car had adequate time to precondition? In our case the supercharger was only 10 minutes away when we started our trip with ~30% so the battery wasn't preconditioned fully. The car said 40-45 minutes to charge, but we just waited until the trip screen showed we'd arrive home with 20%, which ended up being a way shorter charge time. I think we ended up with 22% when we got home.

 

[JeffreyC]

Excellent question! On my last long trip the same thing happened to me. Do you know if the car had adequate time to precondition? In our case the supercharger was only 10 minutes away when we started our trip with ~30% so the battery wasn't preconditioned fully. The car said 40-45 minutes to charge, but we just waited until the trip screen showed we'd arrive home with 20%, which ended up being a way shorter charge time. I think we ended up with 22% when we got home.

The car had about half an hour to precondition, so I think that is enough time? I think the take away here is to look at the Energy graph and not wait until the car tells me I have enough charge to continue my trip.

 

[ATPMSD]

Tesla does not provide information on how it determines arrival SOC. I suggest you use something like ABRP where you can set the SOC you want, and use it to determine what you need. When on the road use the onboard navigation system and energy graph to monitor.

 

[ChrisMPK]

The car doesn't want you to arrive with less than 20%, and in my experience it usually shoots for 25-30%. If you leave your destination in the nav and tap cancel charging stops, it will tell you how much battery (as a negative number) you will have when you get there. Just figure out how much you would have to add to get to +20% and charge that much. Or if it's a trip you take often just remember what you need.

-30% at destination, would mean you need to add 50%. If you get to the charger with 15%, charge to 65%.

 

[JeffreyC]

I guess if I were arriving at a destination that did not have any charging capabilities and the nearest Supercharger was some distance away, I would not want to arrive with less than 20-30%. Since my destination last night was my home and I have level 2 charging in my garage, I will use the Energy chart to manage to arrive with about 10%.

 

[roblab]

If you're sure of your charge and usage requirements, remember that YOU ARE SMARTER than the machine, and drive ahead.

 

[xyeahtony]

I dont ever follow the timer. I just look at the GPS and see what my arrival percentage will be and when its at 10% i unplug and move on. I dont need a large margin of safety like some people. With over 100k+ EV miles over 6 years I’ve been fine.

 

[GtiMart]

The "time remaining" which indicated 25 minutes is based on the charge limit that you set, not your destination in the navigation. You needed 25 minutes to reach your 80% or whatever limit you had set.
If you scroll down the turn by turn steps of the navigation, you'll see what percentage the car currently thinks you'll arrive at. Let it charge until you have a much SOC remaining as you'Re comfortable arriving and leave the SC.

 

[TomServo]

If you scroll down the turn by turn steps of the navigation, you'll see what percentage the car currently thinks you'll arrive at. Let it charge until you have a much SOC remaining as you'Re comfortable arriving and leave the SC.

And This is why I hope Tesla will find the time to move the Arrival SOC box from the BOTTOM of the Nav Turn By Turn steps to the TOP. I use that number to set my GO TIME vs the "time remaining" number, which has NEVER failed in predicting my Arrival SOC to a single percent delta.