Over-analyzing a Week-End Camping Trip

This is a quick write up over last week-end’s camping trip. Read if you are new to EVs, or want some examples of what information loggers like TeslaFi can give you. The best part of logging? You don’t have to take notes, you can just look at the data in the comfort of your home. And normally I don’t spend time writing things up.

Last week-ends trip melted down to a single night, due to lots of calendar conflicts. Still, we were able to squeeze it in. It was just my wife and I, so we decided to not bring a tent and sleep in the car. The trip took us from the Bay Area to the a reservoir in the foothills of the Sierra Nevada. We could have just loaded the car, driven there and back, and Tesla would have told us when and where to charge. It’s 265 miles round trip, so we will need to charge, but there are plenty of SC on the way. But I rather obsess over minute details.

A quick ABRP search gives a rough plan: five minutes charging in Tracy on the way back. We’ll be sleeping in the car, and if we use more than say 10% overnight, we can always stop at the Supercharger in Copperopolis (on the right, close to the destination) or in Manteca (on the alternate route, in the middle)

As we approach Copperopolis two thoughts cross my mind. First, I want to check out the Supercharger for touristic reasons, and second I might as well charge, and have some extra capacity in case plans change tomorrow. Also, it’s always better to arrive with 80% at the campground, than with 50%. There is also the issue of a deserved and needed bio break after two hours of driving. So we pull in, explore the town, and charge.

As we get back to the car, it stopped charging at 80%. By now we were the only car, but Tesla still thought it was a high demand charger, and limited us to 80%, and then charges idle fees. I could have manually set the limit back to 100%, but I didn’t think of checking.

At this point, we drive to the campground, meet friends and enjoy the next 16 hours. This is a boater campground, and most sites feature a truck and a boat. I mentioned that truck and boat in the next site cost more than my MYLR. Turns out each of them costs more than a MYLR. We were the paupers on that campground.

Tesla Model Y at Night
The ISS made a pass that night, but the angle didn’t work out. The line is just a plane.

The next day we decide to do a detour to a winery, and then drive home, with a short stop at another reservoir. The car could have made it, rolling in on 2%, possibly after driving 55mph for a while – easy given the traffic jams. If I’d charge the full time in Copperopolis we’d have been fine. But between bio break and desire for iced coffee we stopped in Tracy to buy drinks, and that got us home comfortably.

High Level Summary

Let’s start with a high level summary.

TeslaFi graph of the actual route driven. Total was 296 miles, mostly due to having lunch at the winery. The right charging stop (Copperopolis) was on the way up, the left (Tracy) on the way back.

Teslafi creates a nice summary of the trip. Total miles driven (296 miles) and how many rated miles this would be (381 miles). Current rated range of the car is 298 miles, so charging was required. The efficiency is 78%. That’s kind of low given it was warm, and and much of the driving is on roads with 55mph speed limit, and freeways were slow due to traffic. We will look at that in more detail below, just because we can.

The cost numbers are bogus, it’s based on whatever I told ABRP to assume for charging cost, and I don’t even remember what that is. Ignore them.

There are three charges listed, because when I came back at Copperopolis and realized the car stopped, I decided to charge more before I decided it’s not worth it. As a result there was a one minute charge

Tesla Supercharger charges.

Total actual cost for the charging are $23.47. They didn’t charge me for idling, I returned just in time – but it would have been better to keep charging those 4 minutes. Also note that the two charging sessions were about the same amount of energy, but the Copperopolis (20min) lasted almost twice as long as Tracy (8 min). Tracy started at 22% vs Copperopolis at 49%. Cars charge faster when the battery state of charge (SoC) is lower.

I did start the trip at 96% and returned home at 29%. Those 67% of battery add another $11 at off peak home charging of $0.20/kWh. Total cost $33.47 for 296 miles, or 11c/mile. Lunch at the winery for two was $27, not including the wine.

So much for the high level stuff. It’s fine to move on with your live now, but we have a lot more data.

Drive by Drive Analysis

Below are all the drives and charges on Sunday. Ignore any cost numbers. The blue half circles show the Safety Scores for each segment. You see how Tesla limited charging to 80%, and stopped at 1:50pm. We returned 1:54, and I started charging again, for one minute. There are even more detailed views in TeslaFi, that actually shows you the parking before and after the charge (1 minute each) and the break in the middle (4 minutes).

The drive back is below. Note that you can drill down into each of these drives to get a lot more information, including elevation profiles, speed, temperature, fan status, inside and outside temperature and more. You can also show all parking and idling, and even when the car goes to sleep.

One data point is that we added 100 miles in 8 minutes in Tracy. This is the time it took us to walk to BevMo, chose among the poor selection of non-alcoholic drinks, pay, and walk back to the car. We added 30% in that charge, and made it home with 29%. All we really needed (other than cold drinks) as a few percent of charge.

The Night

One more interesting aspect is what happened overnight? TeslaFi has some data, too. It starts with an aerial view of the campsite, then a summary, and below that you see the incredibly detailed updates that TeslaFi collects. There is a little note about a drive that may have occured. It did, I actually moved the car to the site across the campground road, and TeslaFi missed that. Oh well.

If we look at the summary, we find that the car was parked at the campground for 18 hours 34 minutes. Inside temperature was between 73 at 3pm and 87 at 10am, while outside temperature dropped went from 77F to 68F.

Detailed data shows (not shown below) the inside temperature going to 101F at 4pm, and cabin overheat protection kicked in. It used about 3% until 6pm. We went to bed around 11pm, and the detailed data said 65% at that time . So we used 5% sitting there 8h from 3-11pm. We were in camp mode set to 70F and later 67F the whole night. At 6am, the outside temperature was down to 51F. We got up at 7am, at 57%.
Overall, pretty ideal conditions in terms of energy consumption and the car used 13% of battery, or 43 miles of battery to cool and heat for 18 hours. 8% just for the night.

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Last Updated on June 3, 2022.