Educated Guesswork

New EV Habits for ICE Vehicle Owners

Man waiting to charge

Generated by Midjourney. Prompt "Man waiting for EV to charge, bored expression, EV charging station, photorealistic --ar 4:3"

I spent some time reading this HN thread in response to Wired's article on how many EV charging stations we need and I'm dumber than when I started (isn't that usually the way it is on the orange site?). On one side, we have the Internal Combustion Engine (ICE) forever crowd enders worried about the tragedy of wasting 30 minutes charging on their 500 mile road trip and on the other side we have EV lovers acting as if there's really no tradeoff.

I have two EVs so there's no doubt about what side of the argument I'm on, but I'm also not going to tell you that it's not inconvenient at times. The truth is that EVs really are a lot more convenient for most people for day to day driving but less convenient for long road trips, especially if you treat them the way you would an ICE vehicle rather than adapting yourself to their idiosyncrasies.[1]

Background Facts #

The two basic vehicle parameters that dominate any discussion of EVs versus ICE vehicles are:

  • range: how long you can drive without refueling
  • refueling speed how long it takes to refuel

Range #

When EVs were first introduced, range was fairly bad,[2] but things have gotten a lot better. Edmunds lists the Toyota RAV4 as the most popular non-truck ICE vehicle,[3] and the Tesla Model Y as the top EV. Both of these are compactish SUVs, so pretty comparable. The RAV4 Hybrid gets about 38 mpg highway with a 14.5 gallon tank, so has a range of about 550 miles (this is a little hard to estimate because it's a hybrid). The most popular EV, the Tesla Model Y, has a listed range of 320 miles.

This is a real physics problem for EVs because the energy density of batteries is much worse than for gasoline cars: the RAV4's gas weighs about 120 lbs; the Tesla's battery weighs 1700lbs. What this means in practice is that adding range to an EV involves tradeoffs in terms of cost and weight but it's trivial to add range to an ICE vehicle just by making the tank a bit bigger. If Toyota has chosen 14.5 gallons, that's because they don't think you need more.

Power Units versus Energy Units #

The terminology around EV units can be a bit confusing. A battery stores a certain amount of energy, which is conventionally measured in kilowatt hours (kWh), which is to say the amount of energy you would put into the battery if you added it at the rate of one kilowatt (kW) for an hour. What's a kilowatt, then? It's 1000 watts, where a watt is the power needed to transfer one joule (the SI unit of energy) per second.[4] In other words, a kilowatt hour is 3.6 million joules (3.6 megajoules (MJ)). Electricity tends to get sold in units of kWh, which is probably why batteries are rated this way rather than in MJ.[5]

EV efficiency varies dramatically, but a reasonable estimate is around 3-4 mi/kWh (5-7 km/kWh). Battery size also varies quite dramatically, but the median is around 75kWh. Multiplying these two values you get a range of 225-300 mi, which is about what you should expect from the above.

Refueling Speed #

ICE vehicles charge faster than EVs. Period. The HN thread had some crazy fast estimates, but gasoline pumps do about 50l/13 gallons per minute, so we're looking at on the order of 5 minutes to fill up your tank. No deployed EV battery charges even remotely this fast.

At a high level, there are three main types of charger in the US:

AC level 1:
Plugs into an ordinary 110V socket. About 1-2kW.
AC level 2:
Requires a dedicated circuit but installable in your home. Typically around 7kW.
DC Fast Charging ("Level 3"):
Commercial charging stations. Typically between 30 and 350 kW. My experience is that there is a lot of variation in actual charging speed for fast chargers, both in terms of rated power and in terms of actual power delivery. In addition, not all cars will charge at the maximum speed of the charger, with newer cars doing better.

Of course, what really matters isn't the rate of power delivery but rather the rate of range added. If we assume 3.5 mi/kWh, we get something like:

Charger type Charging power miles added/hr Time to add 250 miles of range
L1 1.5 5.25 47 hrs
L2 7 24.5 10 hrs
L3 (normal) 50 175 85 minutes
L3 (fast) 150 525 29 minutes
Tesla Supercharger (rated) 250 875 17 minutes
L3 (ultrafast) 350 1225 12 minutes

As I mentioned above, real world experience varies. As a reference point, I have a BMW i3 and a Kia EV6. The BMW will nominally accept up to 49kW, but I don't think I've ever seen above 40. The Kia will nominally charge at up to 233 kW, but I think the highest I have ever seen is around 180 kW. It's also important to know that charging slows down quite a bit once the battery hits 80%, so as a practical matter it takes a lot longer to get to the full nominal range of the car than it does to get to 80% range. Again, this isn't an issue with gas cars where filling rate is comparatively constant.

Day to Day Driving #

The day-to-day driving experience for an EV is totally different from an ICE vehicle. With an ICE vehicle, you just drive around until you are low on gas and then visit the filling station. If you have an EV and a home charger—which you really want to have[6]—you basically never have to use a public charger on a daily basis, even if all you have at home is an L1 charger. all you do is plug your car in when you get home, which quickly becomes a habit. If you have a home L2 charger, you don't even need to do it every day.

The average US commute distance is 42 miles, which represents about 8 hrs on an L1 charger. This means that if you just drive to work and back and you're at home for 12 hrs a day, you'll always have a full battery when you leave in the morning, with about 4 hrs to spare. As long as you don't drive more than 60ish miles, you'll still have a full battery every morning. This means that you almost never have situations where you get up, are late for something, and realize you need to stop and get gas, as happens with ICE vehicles.

Obviously people don't just commute and if you take a longer drive then you'll use up more of your battery. However, on a day to day basis, most people don't drive more than the range of their car. If you drive more than overnight charge's worth in one day, then you'll just have a slightly less than full battery, but the net amount of drain is just however many miles you drove minus the amount you can charge overnight, so unless you have a lot of days with long trips, your battery never gets too low, and when you return to a normal pattern, it will refill again, unless you routinely drive as many miles as your charger can support.

For example, consider someone who has an EV with a range of 200 miles and drives 40 miles a day regularly, then has a few days where they need to drive 80. Here's what their battery state looks like after the overnight charge:

Day Morning Range Miles Driven Evening Range
1 200 80 120
2 180 80 100
3 160 80 80
4 140 40 100
5 160 40 120
6 180 40 140
7 200 40 160

The bigger your battery, the longer you can sustain periods when you're consuming more than you're charging (this is of course also the situation when you're driving the car). Consider a vehicle with a 100 mile battery driven the same way:

Day Morning Range Miles Driven Evening Range
1 120 80 20
2 80 80 0
3 60 80 -20 (oops)

On day three, instead of being down to less than half the battery, you're actually at negative battery instead! The only difference here is that you don't have as big a buffer, so that when you consume more than you charge you run out. The bigger the battery, the more buffer you have and therefore the less of a big deal it is if you do a long drive one day. This buffer is built up in the days before your long drive when you're charging more than the drain; with a small battery, the car is just sitting fully charged whereas with a big battery it would still be charging.

Of course, all of this is just with an L1 charger. If you have an L2 charger at home, then 12 hrs of charge is around 300 miles of range and so you'll nearly always have a full battery in the morning and will essentially never have to visit a public charger. You really just have to worry about situations where you do enough driving in one day to completely deplete your battery. This brings us to the topic of road trips.

Road Trips #

It's clearly more convenient to not have to worry about refueling on a day-to-day basis, once you want to drive more than the range of your vehicle in one day, the situation gets quite a bit worse. In an ICE vehicle you can just generally drive from point A to point B and when you get low on gas, pull out your phone and look for a gas station. This is not a good plan for an EV for several reasons.

First, there are a lot fewer EV chargers than there are gas stations. As of Jan 2024, California had less than 2000 DC fast charging stations (there are around 7000 total in the US). By comparison there are over 13000 gas stations in California. Moreover, because of charging network incompatibility, you can't use every charger (though Tesla is supposed to be opening up its network to non-Tesla cars, which will improve the situation for non-Tesla owners, as Tesla operates the biggest network).[7] The result of this is that when you get down to (say) 30 miles of range, you may not be able to find a conveniently located fast charger. And because the range of EVs is somewhat lower you will need to find a charger more often.

Second, as should be clear from above, EV charging is significantly slower than filling your gas tank even in the best case scenario where you have a fast DC charger (say 10-20 minutes). If you can only find a normal L3, you're looking at closer to an hour. I wouldn't generally even bother with stopping at a L2 charger, though they can be useful for charging overnight at a hotel or something. You can, of course, sit in your car at the charger for 30-60 minutes but it's not an ideal experience. Worse yet, it's not uncommon for the chargers to be full and/or one of the ports to be broken, in which case you also need to wait for someone else to finish.

Basic Strategy #

My recommendation instead is to lean into the way an EV behaves rather than trying to treat it like an ICE vehicle. What this mostly means is to plan your trip around actually stopping to charge.

As a real example, consider a trip from Palo Alto to Los Angeles in my Kia EV 6 GT (range: 210 miles). The total trip is 360 miles, so I should be able to do it with one charging stop, as long as it's located more or less halfway through. There's really only one choice here, which is Kettleman City, located 184 miles from Palo Alto and 178 from Los Angeles, where there is a 10 port Electrify America charging station. The station itself is located at Chalios Mexican Restaurant, but it's in a complex with a pile of other fast food restaurants (In-n-Out, Baja Fresh, McDonalds, etc.). To be honest, this is actually on the good side in terms of location options; lots of Electrify America stations are in Walmart parking lots. Anyway, what you want to do here is plan to get there around lunchtime, plug your car in, and then go grab some food while it charges. If there's a spare port when you arrive, it's actually reasonably likely that charging will be done before you finish eating (be nice, move your car), but even if not, you can just chill in In-n-Out for a bit.

This is basically the only good option if you have an EV with a 200-odd mile range and you want to make one stop: the next closest choices are Coalinga (203 miles from LA) and (214 miles from Palo Alto). you might make it with one of these, but you're cutting it a lot closer than I like. By contrast, if you have an EV with a 300 mile range, you could pick either of these, or even make it down to Bakersfield before finding a charging station. Of course, if you had a 400 mile range (e.g., Tesla Model 3 or S long range, Rivian R1, etc.) then you can actually do the whole trip in one shot, though you'd need to charge when you got there.

Trip Planning #

For the best result, an EV trip requires a lot more planning than with an ICE vehicle. I've certainly done trips where I just drove for a while and then searched for a charger, but this definitely has a higher risk of charging in a Walmart parking lot. You're going to be happier if you do some advance research. There are a number of trip planning tools available to you (Tesla, PlugShare, A Better Route Planner). There's no magic here, just put in your source and destination and play around a bit. Some of the tools will actually recommend specific stops and some you have to do it manually, but in either case you end up with an itinerary telling you where to stop.

Less good cases #

The Palo Alto to Los Angeles trip is basically the best case scenario: California has a lot of EV chargers and you can take Interstate 5 pretty much the whole way, so you're never that far from something. Even so, I tried a few experimental but realistic trips (Palo Alto to Yosemite, Denver to Silverton, Los Angeles to Beaver UT[8]), and was usually able to find some kind of route. There's even an Electrify America charger at the Days Inn in Beaver, so you're not stuck at 10% when you arrive. With that said, you could easily spend a lot of time in gas station and Walmart parking lots.

Probably the worst case is when you are headed to somewhere remote and there may not be a charger, so you need to plan for a round trip. For instance, Lone Pine California doesn't really have anything in the way of non-Tesla chargers, and there are only two stations on the way:

  • A Chargepoint L2 that might have one L3 port in Beatty
  • A pair of non-networked L2 plugs in Stovepipe Wells

Honestly, this would all leave me feeling pretty antsy and I'm not sure I'd want to do that trip in an EV that didn't have a really long range. You don't want to be stuck out in the middle of Death Valley with a dead battery.

Summing Up and the Future #

The bottom line is that neither an EV nor an ICE vehicle is overall better in terms of convenience. For day-to-day driving, just having a car which basically never needs to be fueled is clearly a win, so as long as you have a charger at home, it's hard to go wrong with an EV. You just have to remember to charge it every night.

When it comes to road trips, an ICE vehicle is more convenient, but you can close a lot of the gap with some good planning in terms of when you stop and charge. If you try to drive an EV the way you would an ICE vehicle by just driving until you are low on charge and then looking for a charger, you're going to have a much worse experience.

The good news is that the EV charging situation is getting rapidly better on all three fronts: (1) Batteries are getting bigger so you need to charge less frequently; (2) charging is getting faster so it's less of a hassle; and (3) more stations are being built so you have more options in terms of where to charge. As of today I'd feel comfortable doing most road trips on the West Coast in an EV, but there are still a few for which I'd want to rent something else, which seems like a reasonable tradeoff for the other ways in which an EV is better. If you buy an EV in five years or so, I expect there will be very few trips you won't be able to do in it.

  1. I'm talking here just about charging, but obviously there are a lot of ways in which EVs are just plain better, starting with dramatically better driving performance. I'm not here to sell you that, though. ↩︎

  2. For example, the original BMW i3 had a range of less than 100 miles in 2014. ↩︎

  3. The top 4 vehicles are all trucks. ↩︎

  4. As a reference point, a reasonably fit person can put out around 300 W on a bike for an extended period of time. ↩︎

  5. Note that this isn't some scenario where we're using goofy non-metric units. kWh are still defined in a sensible way from the base units, they're just not the SI official way of doing things. Calories (the amount of energy to heat a gram of water by 1oC) are in a similar position of being a metric but not SI unit that is widely used in specific contexts. ↩︎

  6. Exception: people who can charge at work ↩︎

  7. For non-Tesla owners, this mostly means you want Electrify America, which operates a lot of 150 kW and 350 kW DC chargers. The bad news is that it's not at all uncommon for EV chargers to be broken. ↩︎

  8. Ultrarunners may be sensing a theme here ↩︎