Monday, October 23, 2023

The Test Trip V1


     Over the past couple of months, we have been getting used to mostly driving an electric car.  It has become clear that our daily driving needs are more than met by having a Tesla and charging at home over night.  Our normal daily activity can actually be exceeded with a 110v 15 A mobile charger, but having a 220v 48A wall connector gives us flexibility to guarantee we can fully charge a completely drained battery over night.  So, at this point, I am trying to put myself into a situation where I need to charge;  technically, I didn't really do that yet, but I was a little nervous testing the limits of the battery while taking my family through a mountain pass with occasional drops in cell phone reception.

     So, to keep this kind of data focused, I created a Grafana Dashboard for the trip.  The dashboard itself was 99% created by TeslaMate, and I filtered the data from the time I parked my car the night before until I got home.  I included just a couple minutes of charging after I got home to make sure I had the final battery percentage in the tables.  I hope you enjoy!  

     So, moving to the trip, my original plan was to charge the battery to 100% over night, drive over a 4,000ft mountain pass to the village of Leavenworth that is about 100 miles away, charge at that location while hanging around town for the day, then drive home along the same route. It turns out, as soon as my kids learned they can watch shows on the screen while parked at a charger, they insist that we let them watch as soon as we plug in.  This was okay with me, as it gave me some time to get out, stretch my legs, and walk into a nearby market that actually had normally priced products.  There were 13 chargers at the station, and only about 5 of them were occupied by vehicles charging.  One was occupied by someone who parked their Tesla at the charging station but was not charging their car.  Very rude, and poor etiquette.

The total trip distance turned out to be 221 miles, and it cost me about $13.90 for electricity.  By contrast, if we had made the same trip in our Honda Odyssey, the 11 gallons of gas would have cost us about $55 based on local gas prices, which hover around $5/gal if you shop at Costco or a grocery store.  As I'll cover a little when going over the charging, you will see I could have cut nearly 25% off of the electricity costs if I were more aggressive with my battery.

     I had set the wall adapter to charge the car as slowly as possible the night before.  I don't know if this actually matters, but I have never charged the car to 100% before, and wanted to put as little stress on the battery for this first trip.  It ended up taking around 10 hours to charge, but I could have done it in 3 or 4 hours if I maxed out my Tesla Wall Adapter.  You may also notice that when I charged in Leavenworth, I added 30% capacity to the battery, and I returned home at the end of the day with 43% capacity.  This means I did not need to charge the car at all that day, and I could have either completed this trip on a single charge; meaning I could have saved $3 by charging at home compared to using the charger in Leavenworth.  Alternatively, I could have charged the battery to 80%, and put less wear and tear on the battery by not charging to 100%.  So, it turns out this trip, which apparently a lot of people think is too long for a day trip, 

     Here I take a look at my battery state of charge for the trip.  I had gone a couple days before the trip without charging, which is why the battery was under 40% the night before, and you can see I slowly charged the battery over night.  This was done by setting the charger Amperage to try and target my originally scheduled departure time of 8AM; as usual, the family did not like to wake up in the morning, so our actual departure time was a couple hours later.  Our power usage increased steadily as we traveled over the mountain pass, then leveled off after crossing Steven's Pass.  The majority of the time, we were traveling 55-60MPH the entire time, but I don't think anyone would be surprised to hear that mountains effect battery consumption.  We charged up in Leavenworth before parking and hanging around town for the day.  Finally, you can see on our way home, we used a lot of battery initially on our way up the pass, and actually regained about 3% going down the other side.  The weather was dark and fogging going down the west side of the pass, so we actually slowed down to around 45MPH.  Regenerative breaking was used to maintain speed, and this resulted in a little boost.

     Finally, here is the elevation chart.  I cut off the left side because it was a long line sitting at 387 feet.  You can see the mountain pass was about 4,000 ft high, and Leavenworth is about 1,100 ft in elevation.  you will also notice right around noon, we stopped at a rest area for the kids.  Like I have read many others report, we need to stop for bathroom breaks far more often then we need to stop and charge the car. You can also see while in Leavenworth, we moved the car down by the river at about 17:00 so the kids could play in the park for about an hour before we drove home. 

     In conclusion, the Tesla was perfectly suited for this type of trip.  I also have no doubt that most electric cars these days would have a similar experience.  There is an Electrify America charging station just a couple blocks away at a grocery chain across the river from the Tesla chargers, but I didn't actually investigate to see if it was good.  I will also noticed that several hotels in the area have destination chargers, which could be nice if you were staying overnight; however I have no experience with that.

     In hindsight, I think I should choose a slightly more challenging route for a road trip in preparation for our cross country journey.  Maybe something with an overnight stay that requires stopping to charge in both directions to reach our destination.  We also primarily drove 2 lane highways for this trip, and I've heard that Interstate highway travel uses more battery.  So, until the next phase in my electric car journey, I will go back and plan something.

   One final note about the driving experience.  As I commented to my wife at one point, the Tesla pretty much drove itself on Basic Autopilot for the entire trip.  I had my hand on the wheel, and there were 2 or 3 disengagements where I didn't like the way the car was handling some of the sharper turns, and I often found myself uncomfortable with how close to the center line the Tesla would drive.  I am confident it was just keeping the car centered in the lane, but I do prefer hugging the outside line when going 60mph on a 2 lane road; I just don't trust the other people to stay on their side that much.  However, the basic autopilot functionality did surprisingly well on those curvy mountain highways.

So, that's all for now.  I will start planning for a longer road trip, but I'm really starting to feel good about this cross country trip!