Should you buy an EV?

Should you buy an EV?  Seems like a trend...

Let's get the most obvious reason out of the way first.  EVs are easier, smoother, quieter and more fun to drive than ICE cars. By a lot.   Also, instant heat in the winter, and full blast AC when stopped in the summer.  

But, you don't generally buy a car for that.  You buy it for transportation and you want it to be economical.  Here, it's a bit muddier - but maybe not as much as you might think.  

Best case.  You own two cars, one is ICE.  You have access to 240 VAC in your garage/driveway.  Most of you driving is local. You enjoy driving.  An EV is a slam dunk.  It will save you a lot of money and you'll fight over who gets to drive it.

Worst case.  You only have one car. You have no daily access to 240 VAC charging.  Most of your driving is road trips. You live in a cold climate.  Here, you really need both eyes open before you decide on an EV.  It'll be require more daily planning and may not save you much at all.

First some basics.  

A battery is not a gas tank.  

"Filling" a battery requires some knowledge.  Similar to having to know what grade of fuel and oil you need to feed your ICE car, you need to know some things about your battery and chargers.  

Cost of electricity

While the cost of gas varies only a little from place to place - currently about $3-4/gallon for regular, the cost of electricity for your EV can vary a lot.

Residential rates:  Typically about 12 cents a KWhr, but can vary from 4 cents to 25 cents depending on location and rate plan. This is generally 3 to 4 times cheaper than gasoline for local driving.

Fast DC chargers:  These generally vary from 30 cents to 60 cents a KWhr.  This is the same, or more than gasoline for ICE cars for highway driving.

Free charging:  Yes, free!  There are lots of businesses that offer free charging.  If you are eating out or going to a movie or shopping, you often can grab 5-10 KWhrs of juice while you're out.  Some employers offer free charging for employees, as well.

Charger types

There are three types of chargers.  Level 1, level 2 and Fast DC.

1. Level 1 is what you can get from a regular electrical outlet.  A level one charger will get you a bit more than1 KW, or 5 miles for every hour you charge.  

2.  Level 2 is 240 VAC and typically 30 amps or more.  This can get you up to 11 KW, or 50 miles for every hour you charge, although many are about half of this.  If you have an electric dryer not too far from where you park your car, you have access to level 2 charging.

3.  Fast DC charging is  depends on two things.  The rating of the charger and the car's on board charger.  The best will be over 200 KW, the worst, 30 KW.  

Take-away:  The sweet spot is having a level 2 charger in your garage.

The battery

There are two main types of battery chemistry in use, and although the "best practices" vary between them, generally, these things are true.

1.  You generally don't want to "fill" to 100%. unless you're heading out on a trip.  If you fill to 100% all the time, your battery life will degrade a bit faster.  (this 100% rule doesn't apply to LFP batteries, which are becoming more common)

2. You generally want to charge a little bit, often, rather than a lot, infrequently.  It's better for the battery to go from 60-80% every day than 20-80% every three days.  (In fact, if you do this all the time, your battery will last 800,000 miles before it degrades 15%)

3. Fast DC charging rate will vary depending on battery state.  If the battery is over 80%, the rate will decrease as the battery approaches "full".  If the battery is cold, it will charge much more slowly than if it is warm.  Many cars have battery heaters that allow you to warm the battery before charging.  

4. For fast DC charging, the rate the battery will charge depends on the car, not the charger.  

5. Fast DC charging is generally a bit harder on the battery than charging on a level 1 or 2 charger.

Take-away:  Having a level 2 charger at home means you can start out every day "full" (or nearly so)

Road trips vs local driving.

EVs win both in terms of efficiency, (https://blerfblog.blogspot.com/2024/11/fuel-economy-whats-your-mpg.html)  but the gap is narrower for road trips.  Why?  Regenerative braking isn't used much on road trips and ICE engine efficiency is a bit higher for constant load/speed conditions of highway driving.

Cost of charging vs gas.  

Charging at home is typically 8-12 cents per  KWhr.  Charging at a fast DC charger is between 30 and 60 cents a KWhr, depending on time of day and vendor.    Gasoline is running about $3/gallon.

At 2.8 KWhr per mile (typical highway efficiency) for an EV and 25 mpg for an ICE car, and 50 cents per KWhr and $3/gallon, that's 17 cents per mile for EV and 12 cents per mile for ICE.  

But, remember, that the "first tank" for the EV is likely at the much cheaper residential rates, so, a 400 mile trip with 150 miles at the residential rate of 12 cents and the rest at 50 cents per KWhr averages out to  13 cents per mile - about the same as ICE.

Battery size and range

Most cars have batteries between 50 and 100 KWhr and have range between 200 and 350 miles.  

Most people rarely drive more than 100 miles a day.

Range only becomes an issue on road trips.  This isn't a show stopper - but it does require more attention than taking an ICE car on a road trip.  More later.

Take-away. Most EVs are perfect for most people, most days.  

Charge planning

Assuming you have access to level 2 charger, start your day with 80% charge, 100% if going on a road trip, or need the range for the day.  Plug car back in and charge back up to 80% at the end of the day while you sleep.  Simple.  Cheap.  Much better than having to plan a stop at a gas station every few days.

If you are driving more than your range, plan on a stop to charge.  This is typically going to be a fast DC charger.  This is NOT just like stopping for gas.  It requires some planning.  It takes longer.  Chargers are not ubiquitous.  

Here's the basics.  

1.  It takes as much time on the charger to go from 20 to 80% as it does to go twice from 50 to 80%, so plan all your meal and rest stops around charging and charge every time you stop.  

2.  There are no signs along the highway, so use a route planning tool or Google Maps, or car's navigation system to find and plan your stops.  Make a quick list and do some Google maps street view scouting before you go to know what your alternatives are and what the amenities near the charger are like.  

3.  Know what the charger rating is and know how fast your car can charge. A 350 KW charger will NOT charge your car that fast if your onboard charger can only do 125 KW. 

Trying to go from 20-80% at a 60KW charger on your 100 KW hr battery will take an hour.  Maybe okay for a meals stop.  Going from 50-80% on a 150 KW charger will only take 12 minutes. Just about enough time to hit the restroom or grab a coffee.

4.  Use a planning tool to adjust your plan on the fly.  Need a rest stop sooner, or want to push a bit more down the road or want to avoid waiting for a charger?  You need to do some planning.  

5.  Do you have use of Tesla Superchargers?  If you do, you have a lot more choices and far fewer time spent waiting in line for a charger.  Know that some cars, for technical reasons, will charge about half as fast on a Tesla charger than other fast DC chargers.  (Teslas have 400 VDC batteries.  Some others have 800-900 VDC batteries and will not charge as fast on Tesla chargers).  

6.  The planning tools will often show you the price.  It can vary a lot.  I know that the Florida Power and Light chargers are only about 30 cents a KWhr, while Electrify America is 56 cents, for example. Choose wisely. Save money.

7.  The planning tools will often have ratings and reviews and will indicate if some of the chargers are broken. They also cann tell you how many are in use, currently.  Good for avoiding lines.

8.  Download the app and set up an account for each of the charger brands you plan to use.  Some require the app to use, or at least, use reliably.  

9.  If driving in cool/cold weather, make sure you understand what triggers your battery conditioning.  For Tesla and Hyundai (and others?), you generally have to have your onboard navigation system routing to that charger.

10.  Charging port.  Does your car have a NACS (Tesla) charging port or a CCS1/J1772 (most everything else) port?  You might want to purchase and adapter plug, depending on your circumstances, to expand your options.  Note, just having a CCS1 to NACS adapter doesn't mean you can charge your car at a Tesla Supercharger.   The Supercharger has to support your brand and car model, specifically. 

11.  If your trip includes an overnight stop, try to find a hotel with free level 2 charging.  Use your planning tools to find out which hotel have one and how availability works and what the cost is.  Also, check a few reviews to make sure others have had good luck there. 

Plugshare and ABRP (A Better Route Planner) are the two planning tools I use to "what-if" road trips.  I use the car's on board navigation while driving (https://blerfblog.blogspot.com/2024/09/owning-ev-road-trip.html)

Also know

Reliability.  EVs currently on the market have terrible to average reliability.  They also have much simpler design and far fewer moving parts.  Then, why is this?  They should be more reliable, right?  EV design is still evolving and some parts and systems are still being refined as automotive engineers tweak the design.  Use Consumer Reports to separate the "naughty" from the "nice" and to find out what the trouble spots are.    I am expecting EVs to have "bullet-proof" reliability as some point in the future, but they are not there, yet.

Maintenance.  Wiper blades and washer fluid, cabin air filter and rotate the tires.  Occasionally the battery coolant.  That's it.  Brakes will last almost forever since most braking is regen.  No oil changes.  No transmission fluid.  No timing belts.  No antifreeze. No carbon build up, intake or throttle body cleaning.  

Towing.  You can tow with many EVs, but know that it will absolutely clobber your range - like in half.  Some newer EV pickup trucks have really huge batteries to get better range, but that extends your charging time at fast DC chargers. The market isn't really there yet, for the full time RVer - unless you have a motor home and have a TOAD.  An EV would be an ideal TOAD.

Cost to replace the battery

This is the biggest "red herring" out there!  Yes.  Some people have had their batteries replaced because they fail prematurely.  But, the battery warranties are really long and failure rates are really miniscule.  Batteries will degrade a bit over time, but real world experience has shown degradation is slower than predicted by lab tests.  Even if you don't generally follow the "best practices" for your battery, you'll have 85% or better at 200,000 miles.  

Some use cases

1.  You are a family of four, have two cars.  Both used for daily commutes during the day, and kid taxi on evenings and weekends.  Once a month, there are long vacation road trips of 300 - 1000 miles, one way.  One of your cars should be an EV.  Period.  End of sentence.  Use the ICE for road trips.

2.  You are single and live in an apartment complex. You commute every day and take 400 mile road trips two weekends a month.   Can you charge at work? Does your complex have a level 2 charger?  Can you move to a place that does?  Can you lobby your landlord to install some?  Can you sneak an extension cord out a window to your car for level 1 charging?  If not, an EV is likely going to be more work than you're willing to take on.  Think hard about it before you take the plunge.

3.  You are married and live in urban home with street parking.  Commuting is by transit.  Vacation travel is by air.  Why have a car at all?  Rent one when you need one.  Maybe the EV for you is and Ebike. 

Conclusion

Should you buy an EV?  Right now?  Mostly yes, but know what you're getting into.  As EV technology and design improve and charging becomes more ubiquitous, the yes/no line will move and EVs will be even cheaper, more reliable and easier to own.

It's really a matter of "when", not "if.  

Fuel Economy - What's your MPG?

 ...or, in EV terms, your mi/KWhr?

The answer is... It depends.  And, it depends more if you're driving and EV.

We've been driving gasoline (or diesel) cars for a loooong time.  We think about fuel economy in terms of mile per gallon.  We kinda know that we get better mileage on the highway than driving around town.  We've been told things to help us improve our MPG, like "avoid jackrabbit starts" and "avoid abrupt stops".   The government has even gotten in on the game, mandating fleet average fuel economy numbers and publishing "EPA city and highway" fuel economy numbers, e.g. "18 city, 27 highway mpg".

Now, EVs show up and the whole game seems upside down.  How do you even compare?  One way is with MPGe, or MPG equivalent where you take the electrical energy and just convert, knowing there are 33.7 KW-hrs in a gallon of gas, if you burn it.  This is a pretty fair comparison, actually.  If you buy a gallon of gas, it costs about $3.00.  To buy 33.7 KW-hrs at 12 cents per, it would cost $4.00.   

I compared a Hyundai Ioniq 5 with a Hyundai Tuscon (non-hybrid) - similar sized cars - using spreadsheet calculator I built and some trip profiles I created.  Here's the result.

If you'd prefer it in cost per mile...

There's two really noticable things here.  One is the EV is considerably more efficient than the ICE car.  The second is the ICE car does better on highway trips than the ICE car on local trips.  The EV is exactly the opposite!

What the heck is going on?  Is it because of how the cars are propelled or because the fundamental differences in design make EVs move down the road more easily?

There are two parts to making a car go: Propulsion and Resistance.  Propulsion is what pushes the car forward - the engine or motor and the drive train than connects that to the wheels and wheels and tires to the road.  Resistance is what pushes back against the propulsion - primarily the friction/rolling resistance between the tires and the road and the aerodynamic drag - pushing through the air.  Another part of resistance is inertia, that is pushing to accelerate the car up to speed.  

On the surface, resistance wouldn't seem to have much impact.  The EV is a bit heavier, because of the propulsion battery.  Even replacing a heavy engine and transaxle, the EV comes in at 4700 pounds vs 3900 for the ICE. 

But, the EV is a bit more aerodynamic with a coefficient of drag of 0.29 vs 0.33 for the ICE.  The reason here is the ICE needs to allow a lot of air directed under the hood and over the radiator to keep the engine cool.  It is also harder to keep smooth airflow under the car having to deal with exhaust pipes and drive shafts.

Let's take a close look to see how these differences actually play out.

Resistance

Let's start with the resistance.  Here's the fancy equation for steady speed.

 

Where:

c_R     =     coefficient of rolling resistance
c_D      =     drag coefficient
m      =     mass of vehicle
A      =     frontal surface area
g       =     acceleration of gravity
r       =     density of air

The first part is the rolling resistance.  It's linear and goes up with the weight of the car.  It also depends on what the wheel and road are made of.  Cars tires on concrete have a CD of about 0.015.

https://www.omnicalculator.com/physics/rolling-resistance

For my Ioniq 5 EV, it takes about 70 lbs of force to overcome rolling resistance.  To make the car roll, you have to push it with 70 lbs force.  To make it roll one mile, you need 70 x 5280 =  370,000 ft-lbs of energy. 

How fast you can cover the mile depends on the power available.  Power is the rate at which energy is used.  If a person pushing on a car can produce about 1/4 HP, it would take 45 minutes to cover a mile (370,000 ft- lbs x (1 HP/33,000 ft lbs/min)  x 1 person/0.25 HP)

I baked this into a spreadsheet and calculated for various speeds. 

At 30 mph, you need 5.7 HP.  At 60 mph, you need double, 11.3 HP.

If there was no aerodynamic drag, you'd get a steady 7.5 mi/KW-hr.  It wouldn't matter how fast you went.  It takes the same energy to move each mile regardless of speed. Speed just tells you how fast you have to supply that energy.

Now lets add in aerodynamic drag - the second part of the equation.  It really is a drag.  It goes up with the square of speed.  Every time you double your speed, you quadruple your air resistance. 

It depends on  two factors- how aerodynamic the vehicle is and the frontal area of the vehicle. Shape determines the aerodynamics.  A flat fronted truck isn't very aerodynamic as it plows it's way through the air, but a smoothly shaped car would be very aerodynamic as it slices it's way through.   Size also matters.  Two similarly shaped vehicles with different cross-sectional area would have different aerodynamic drag.   The larger one would have proportionally more drag.   

I plugged the numbers for my Ioniq 5 EV into my spread sheet.   Here's the results.

At 30 mph, it takes 16.6 lbs force to move through the air.  At 60 mph , it takes 66.2 lbs.  

Including the speed you are going to the when you are producing that force, gives you this HP curve:

At 30 mph, it takes 1.3 HP.  At 60 mph, it takes 10.6 HP.  Speed kills energy efficiency.

Putting the two parts together, you get this:

Doing the same for the Tuscon and comparing, this is what you get.

Notice the Tuscon rolls a bit easier at low speeds because it's lighter, but a bit worse at high speeds because it's less aerodynamic.

The takeaway here is the differences between the cars in terms of resistance are very slight.

Some more resistance

There are a couple of other ways the car "pushes back."

One is inertia.  If you apply a force to an mass, it will accelerate.  It takes energy to go from a stop to speed or from a lower speed to a higher speed.  A mass moving at speed gains kinetic energy as its speed increases.  That energy comes from the propulsion system.  The equations for this is are

F = ma

where:

F is the net force applied 

m is the mass of the car

a is acceleration

and

KE = 1/2mV^2

where:

KE is kinetic energy 

m is the mass of the car

V is the speed of the car

The energy it takes to accelerate to a certain speed is exactly equal to the kinetic energy at that speed (less any spent to over come rolling resistance and aerodynamic drag).

How fast you accelerate depends on how fast you can deliver that energy.  Higher HP means faster acceleration, but it doesn't change the amount of energy required.

The energy to accelerate my Ioniq 5 to various speeds looks like this:

Here's the HP effect on acceleration

This chart shows acceleration times based on getting full HP to the wheels from start all the way to 60 mph.  Real world acceleration isn't this good for a couple of reasons.  One, is at very low speeds, you're limited to the adhesion of the tires.  Power = force x speed.  If speed is very low, the force is very high and tires will spin - a "burn out".  An ICE engine with a mechanical drive train just can't put out full HP from the start.  Full HP usually requires full throttle close to the "red line" of engine speed. At lower RPM, the max HP is lower.  An EV can put down the full HP almost instantaneously and hold it all the way through the speed range.  

Back to the energy...

The 0.21 KW-hr to 60 mph doesn't look like much compared the 3.5 it takes to move the car a mile at 60 mph, but driving involves lots of braking for stop signs, traffic lights, traffic, etc.  Every time you slow down, you have to spend some energy to accelerate again and that energy is later destroyed as heat from braking.

If you can capture that braking energy instead of burning it off and use it to reaccelerate, your economy will improve.  EVs and to a lesser extent, hybrid cars can do this.  It's called regenerative braking. 

Regenerative Braking

It works like this.  EVs have a motor that is attached directly to the wheels through a reduction gear set and a differential.  

When you put power to the motor, the wheels propel the vehicle.  

When you don't apply power, the motor just spins freely, with a very, very, very slight drag from friction and you basically coast. 

But when you connect the motor to a load and let the wheels drive the motor, you get braking.  You are running the motor as a generator.  If the load was just a big resistor, you'd just make heat.  But, regenerative braking connects the motor to the battery and recharges the battery instead of just wasting the energy.

The concept is simple, the execution is hard.  You have to be able to charge the battery at various rates depending on speed and how hard you need to brake.  You need to have the "regular" brakes on the car available if you need to braking that exceeds the system's ability to feed power back into the battery.  And, you need to be able to manage all this with an accelerator and a brake pedal and have is feel like driving a "regular" car.

The really good news is the cars manage all this for us sophisticated software and provide it whether we go "new school" and use "one pedal driving" or "old school" and step on the accelerator and brake pedal. 

 If your trips involve a lot of braking, you will save a lot with regenerative braking.  If it's a long stretch on freeway, not very much.  More later....

Going up (and down) hills

Hills also require energy to get up.  It takes roughly 20 lbs of force to equalize the force of gravity pulling a one ton mass back down a 1% grade (a 1:100 slope, or one foot up for every 100 feet forward).    However, any route that takes you back to where you started from, eventually, has the same amount of uphill and downhill elevation change so, you would net out zero extra energy from hills. 

However... if you have to apply the brakes to hold speed on the downgrades, you are burning off more energy as heat.

Hilly, local roads with lower speeds and grades above 2% will allow some regenerative braking.  Long, interstate trips with grades generally below 2% provide little.  There is rarely enough downhill pull to exceed the aero and rolling resistance.  

The negative power is available for regenerative braking.  A car without it burns it all off as heat - and has to worry about overheating the brakes or using "engine braking".  

Any route where downhill braking occurs, the EV has an additional advantage over ICE cars.  But, we'll ignore that in the simulated trips - later.

Propulsion

This is really simple for an EV and really complicated for an ICE car.  

The EV has a battery connected to a power supply, connected to a motor or two, that drive the wheels through a conventional differential, shafts and joints.  The performance of this equipment is very high efficiency and varies almost none regardless of speed.  There is just a bit of loss in the battery, wiring, motor and drive train.  It's in the range of 95%.

Gasoline engine drivetrains are more complicated. The problem is matching the output of the engine to the demand for propulsion.  Cars need to go fast and slow, accelerate hard or slowly, climb hills and idle at a stop.  The ICE car has an engine that is a heat engine, constrained by the laws of thermodynamics, whose performance and efficiency vary greatly with speed and throttle setting and requires a variable speed transmission to be able to power the car at all speeds and conditions - starting - cruising - uphill - fast - slow.  The efficiency of the engine typically varies from 15% up to 30% depending on RPM and throttle position.

Part of the reason the low efficiency is so low is a fundamental part of a gasoline engine - the throttle.  You control the power of the engine by adjusting how much air you let into it. When the throttle is mostly closed, the engine gets little air.  Open, the engine gets a lot of air.  The engine always has to have the exact, right mixture of air and fuel for combustion to occur.

The side effect of having a throttle, is the engine has to "suck" the air past the restriction of the throttle.  This wastes a lot of energy.  It's called pumping loss.  Manufacturers have tried hard to minimize this by installing transmissions with more gears - up to 10 speeds - or even CVTs - with infinite "speeds"  so they can keep the throttle as open as possible at relatively low HP cruising speeds.  They also have started using smaller displacement engines with turbochargers and direct injection to further reduce "pumping losses".

Even so, the very low power demands of lower speed "city" driving have very low efficiency, while highway driving with it's higher power demand,  is somewhat more efficient.

This is an engine map of a 2008 Toyota Camry.  The x axis is the engine speed in RPM.  The y axis is torque, which is a good proxy for throttle position (higher = more open).  The curved lines with the scale on the RH side, are power (in KW - one KW = 0.746 HP)  The rings in the middle are engine efficiency (in percent)

The red circle is typical urban driving.  Orange, suburban, Green, highway.  

You can see urban driving in the 10-15% range.  Suburban in the 15-20% range and highway in the 20-27% range.

The Tuscon we're using for comparison has a turbocharged, direct injection engine and does a bit better than this Camry.  But, the principles remain the same. 

Putting it all together - Some simulated trips.  

I created these trips by piecing together moving segments with stops in between each.  I assumed steady speed for each segment and zero time to get up to that speed.

For the Ioniq 5:

These assume that all acceleration energy is recouped as regen braking and the whole distance is covered at the speed limit.   Terrain is level.   Energy is in KW. 

This shows dramatically the effect of regenerative braking.

Without regen braking, the economy is right around 3, plus or minus a bit. In urban driving, it's almost double with regen.  On highway trips, it has almost no effect - there is very little braking energy to recover relative to the miles and miles of aerodynamic drag to overcome.

Now, for the Tuscon.

This shows exactly what many of us are familiar with.  Best mileage on the highway.  Worst in local driving.  Really fast highway driving starts lowering fuel economy.  But, the overall effect is a rather flat curve.  The difference between suburban driving and highway driving is minimal.  

The two big factors driving this curve are:

Lack of regenerative braking. - lowers urban and suburban driving as so much energy get wasted by braking.

Low gasoline engine energy efficiency at lower speeds despite the best engineering to match engine performance to driving conditions with multi-speed transmissions.

Conclusion

EVs beat ICE cars primarily because they are efficient with the stored energy in the battery.  Nearly all the energy stored on board  is used to move the vehicle versus only 15-30% for an ICE car.  Secondarily, the availability of regenerative braking drastically improves economy in local driving.

The weight and aerodynamic differences have little impact on overall economy.

Bonus Info! 

Range and Charging 

If you start talking about EVs, the first question that always pops up is about range. 

People driving ICE cars are used to filling their tank and driving until near empty and then buying more.  There wasn't much to think about.  Gas stations are everywhere, have virtually the same price, and all cars fill in a matter of minutes regardless of make or model.  Range and price don't depend very much on where you fill your tank or where you are driving.

EVs are different. The cars are all different and have widely different fast charging rates.  Energy economy can vary a great deal with the type of trip.  The chargers are different by type and even within type.  The cost for a KW-hr of juice can vary widely between charger brands and time of day.  And, the battery's charge rate can slow a great deal as it approaches "full".  

So, charging requires more planning and thought and knowing your range becomes more critical. 

Let's zoom in.  My Ioniq 5 EV has a 77.4 KW battery and is about 95% efficient getting the juice from the battery to the wheels.  

Here's what the economy looks like at steady speed.

Steady 30 mph, 5.5  mi/KW-hr, steady 60 mph 3.5 mi/KW-hr.  That's a really wide range. 

What range would that 77.4 KW-hr battery give me at various speeds?

400 miles at 25 mph.  200 miles at 75 mph.  A really big range. 

This shows the problem the engineers have in estimating the range to display on the dashboard.  They have no idea how fast you are going to go, they only know how fast you've been going.  Using recent history to estimate is the best they can do.  So, if you've been doing a lot of local driving at 40 mph, it might show 350 miles range for a full battery.  If start going a steady 80 mph, you're actual range is only 190 or so.  

My car will often tell me I have 240 miles range with an 80% charge after I've been suburban driving.  But, I know, if I jump on the interstate and start driving in the high 70's, I only have about 170 miles range.  

Fortunately, having an AC charger at home means not having to worry too much about range.  My practice is any day where I'm going more than a few miles from home, I'll charge up to 80%.  There's no advantage to not letting it get low before you charge.  You're not saving a trip to the gas station!  If I'm heading on a long trip, I'll charge it to 100% the night before.

How does one navigate charging on a road trip?  The key is planning tools.  They are basically navigation systems that will plan your charging stops.  They allow you to filter for the charging station types and brands, your tolerance for how low you care to let your charge get, and what features you need at the stop, like food or restroom.  

The planning will estimate based on the route and roads you'll be travelling, adjusting for your energy  economy.  It will tell you what it expects your state of charge to be on arrival and the minimum you should plan to charge to.  

Tesla has the best route planning tool.  Hyundai and Kia's keep getting better.  A Better Route Planner (ABRP) is an app you can run from your phone and actually have it connect to your car so it knows your state of charge in real time.  

Some tips and best practices for road trips:

For lowest cost on trips, charge to 100% using your home charger before your leave.

Stay at hotels that have free level two chargers and charge to 100% overnight.

Don't plan on charging over 80% at fast DC chargers on your route.  Charging slows down a lot after 80%.

Don't worry too much if you have to use a 150 KW charger instead of a 350+ KW.  The difference in charging time is small.  

Plan your rest stops around charging.  Most times your "bio-break" won't be much shorter than the charging time.

Remember that two fast DC charging sessions from 50 to 80% take the same time as one from 20 - 80% and one charging session from 20 to 80% is shorter than going from 60 to 100%.

If your car came with free charging at some fast DC charging, make sure you filter your route planning tool to take advantage of it.  Fast DC chargers generally are expensive comparted to home chargers, costing the same or more than it would to fuel and ICE car.  

Engine map.  reason for transmissions.  migration to many "speeds"  CVT.  Pumping losses clobber efficicency - engine braking.

References:

2008 Camry 

22 HP for 60 mph  about 2200 RPM

The thermal efficiency map for the I4 engine from a 2008 era Camry (derived from the I4 engine used in Ricardo baseline simulation for a standard car) (AKI 93 fuel)

Rolling resistance

Where:

c_R     =     coefficient of rolling resistance
c_D      =     drag coefficient
m      =     mass of vehicle [kg]
A      =     frontal surface area [m²]
g       =     9.8 m/s
r       =     density of are, 1.2 kg/m³ @STP

 A typical value for the coefficient of rolling resistance is 0.015. The drag coefficient for cars varies, a value of 0.3 is commonly used.

grade resistance 20#/ton

https://www.omnicalculator.com/physics/drag-equation#what-is-the-equation-for-drag-force

https://www.calculatorsoup.com/calculators/physics/kinetic.php

Owning an EV - Road Trip!

50 years ago, I graduated High School in South Jersey.  50 years!  ...not possible. 

Anyway, my class reunion was in Atlantic City and I decided to take the Ioniq 5.  I was really interested in what a road trip using fast DC charging would look like.  I had ridden with my sister in her Tesla Y from South Jersey to Buffalo and back and had gotten a good taste of Tesla Superchargers. But, for the CCS world (most all non-Teslae), would it be as easy?

Sheetz in Stephens City, VA

Short answer - yes. 

Here's the long answer.  

The trip is 780 miles total.  I split it into two days, roughly 500 miles on the first day and 230 on the second.  Actual dwell is from my Google Maps data.  Charging time is from charger data that is kept on the charger app on my phone. 

I only used Electrify America chargers because the Hyundai comes with two years of free EA juice.

Here's the data on the trip up.

So, that's 8 stops for a total of 2:44 dwell.  Comparing it to a trip in 2021 in our old Audi Q5, we had six stops for a total of 1:08.  The EV "cost" about 1:30 over the ICE car in this case.  Note that this is LESS than the 1:56 "plugged in" time because a good chunk of that was unattended - getting food, restroom, etc. 

Also, charging at the hotel avoided a trip to "fill up" as the battery charged while the car was parked. 

The trip back.

Sheetz in Wytheville, VA

That's 7 stops for a total of 1:38.  Comparing it to an Audi Q5 trip in 2021 with 5 stops for 1:07, the EV "cost" about 30 minutes. Being familiar with the whole charging routine and never having to wait for a charger helped a lot.  The reason the return trip had fewer KWhrs at fast DC chargers is that I arrived in NJ with about 80% battery, but arrived back home with only 20%.  Having a charger at home makes things easy.

The Hyundai route planner is actually pretty good.  Just pick you destination in the Navigate screen, allow it to include EV chargers, and it'll pick a route and plan the charging stops.  

Done?  Not quite.  Those stops might not be at the charger brand you prefer - i.e. "free" Electrify America - and they might not be soon enough for a "bio-break".  

EA charger at Walmart in Cordele, GA currently has 4 of 4 chargers available

No problem.  First, filter on the charger type you want from the EV screen settings prior to having the navigation system plan the route.  Then, you can see the first charging stop.  Pressing "more" brings up a list.  By selecting "route", the list will populate with all the chargers in route order.  

You can choose one and add it to your route.  The route will replan from there.  I used this feature in lieu of the Rest Stop tab on the maps screen to plan my next stop. 

It worked very well. 

Some other features.  You can see in real time, the number of chargers at the location and how many are available.  This seemed to be very accurate and it did not show "broken" chargers as available.  It doesn't do any en-route prediction like Tesla, because it has no idea how many non-Hyundais might have the charger in their route.  You can get a good idea of how popular your next charger is by watching the available charger number and planning around it with an earlier or later stop.

Other notes.  

I would only charge beyond 80% under two conditions.  Nobody waiting and it would be tactically helpful to my driving.  It's generally not worth it as the charging speed tapers off rapidly after 80%.  At 90% the rate is down to 40-50 KWs.  

With  free charging, I saved over $200 in fuel on this trip.  But, if I'd have had to pay the going EA rate of 56 cents per KWhr, it would have cost me about $200.  EA is on the expensive side, and some of the other networks are much cheaper - something to explore when my two years of free EA is up.

My driving was very much off-peak, yet I had to wait for a charger a couple of times. Hyundai isn't the only car company giving two years free at EA.  I imagine this will get easier as the "free" EA plans expire and the Tesla Supercharger network opens up.  (First quarter 2025 for Hyundai.)  There is a lot of chatter about "broken" chargers.  I found that about half of the locations had one charger down or some part of it not working exactly right.  This is better than I expected - you often see gas stations with some number of pumps down...

The Hyundai and Kia claim is "10 to 80% in 18 minutes" (or 3.9% /minute) ... I came close once at 3.75%/minute. Generally, I managed about 2.7%/min on 350 KW chargers.  How much did that matter?  Not a bit.  I generally plugged in, went to the rest room, came back and was done or only had a few minutes to go.  Hardly enough time to check my text messages!  I really didn't much care if I plugged into a 150 or 350KW charger.

There is a charging time trade off.  If you trip requires X minutes of charging, It really doesn't matter much if you do it infrequently at long intervals or more frequently at shorter intervals.  Twice for 10 minutes is the same as once for 20 minutes.  The difference is the time it takes to exit the highway and get to the charger.  Fortunately,  all the chargers I visited were almost immediately off a highway exit - no more than half a mile.  The winning solution is to time your meal and bio-stops with charging stops.

The need for speed.  

There is a lot of chatter about not driving as fast with an EV because it clobbers the range.  Two facts.  One, speed clobbers ICE car mileage just as badly.  Aerodynamic drag is the cause and the air doesn't care what's driving the car.  The reason is seems so bad in an EV is the EV's regen braking makes non-highway driving so much more efficient.  I typically get about 3.5 miles per KWhr in suburban driving.  I got 2.8 miles per HWhr at 77 mph on the highway.  I'm not slowing down.  My need for breaks exceeds the car's range.

What's next? Eventually, I'll have to investigate actual, paid fast DC charging, but for now, I'm totally satisfied with Electrify America.

The first 1000 miles - owning an EV

 We purchased and EV.  A Hyundai Ioniq 5. We've driven in about 1200 miles so far.  Here are some early thoughts.

Our EV

It's a car. It has four doors, seats, accelerator, brake, steering wheel, etc. etc.  Step on the brake and hit the start button and it turns on.  Shift into D and it goes.  It's a car!  But...

It's ridiculously quiet.  The loudest sound is road noise and it's pretty well insulated.

It's smooth.  There is zero vibration or harshness from a gasoline engine. It's noticeably absent.

It's smooth, fast, and lots of fun to drive.  We used to have an Audi Q5.  It was fun to drive. This is better.  In fact, I often say, "This is the car the Audi was trying to be."  Why?  Having the battery low and in the center of the car is ideal for handling.  Low center of gravity.  Low polar moment of inertia (weight not out past axles. closer to the center - why mid-engine sports cars are sought after).  This makes for quick and secure handling.  Power is super smooth.  No shifts.  Power is linear and  predictable.   No surprise downshifts or unwanted upshifts.  No lag.   Acceleration is mind-bending and all 300+ HP are available all the time at any speed, instantaneously.  I haven't floored it, yet.

You can do one-pedal driving - if you want to.  Or not. It's easy to set up for one or the other. How much regenerative braking is available when you back off the accelerator is variable using the "shifter" paddles on the steering wheel. One pedal driving means that letting your foot off the accelerator slows the car using regenerative braking.  You can make the smoothest of stops and starts using one pedal driving.  Most trips I don't touch the brake pedal at all, except in reverse.

It's a Hyundai, so the controls and displays are very similar to our Kia Telluride - part of the reason we chose it over other EVs - shallow learning curve and generally easy to use.  Kia is owned be Hyundai.

It has some EV weirdness.  Flush door handles that flip out when you approach with the key.  Regular old door handle would be better and the aerodynamic argument is dumb - it's a tiny, tiny advantage.  There is a lot less weirdness than in a Tesla, however.

It's range in local driving is much more than advertised.  The claim is 262 miles.  Actual range is 310-330 - and this with significant AC load - it's been hot! 

The regenerative braking often captures 50% of the energy spent on propulsion.  The more stop and go, the higher the percentage.   In the trip below, 14 kWhs were spent moving the car - 9 net with 5 recaptured in braking, so 5/14 or 35% was recovered on this trip.  Another two were spent keeping the car cool, the lights on and the 12 VDC battery charged.  A total of 11 kWh for 44 miles of driving is 4 miles per kWh - about 50 cents of electricity.

This was a trip to the airport and back.  Quite a bit of highway driving

It's sooooo cheap to run.  Cost per mile for energy so far is about 3 cents.  Put another way, it's like having gas at 90 cents per gallon. 

Charging at home is really simple.  But, you do have to have a home charger installed on a 240 volt circuit.  A clothes dryer circuit would be plenty and there are devices that allow you to switch between your clothes dryer and EV charging.  We had a ChargePoint charger installed and can charge at 11KW (240 volts, 48 amps).  Charging from 20% to 80% takes about 4 hours.  Plug it in in the evening and unplug in the AM.

An EV battery is not a gas tank.  You don't "fill-er-up" and drive to almost empty.  You just top it up after most days you do any driving at all.  It's a little bit better for the battery's overall life to keep the charge below 80%, so we rarely go above that.  If it's above 60% at the end of the day, I'll skip charging unless a there's a lot of driving to do the next day.  You start every day with "a full tank" without ever having to plan or make a trip to the gas station.

For what we sold our 1999 Expedition for, we purchased the home charger, had an electrician install it and had a Stealth Hitch 2" tow hitch installed for my bike rack. 

Old Ford on it's last day.

Doing a road trip requires quite a bit more planning... The winning solution requires that you plan to charge and take a rest break at the same location.  It looks like a 15 minute stop every 150 miles would do the trick - the Ioniq charges really quickly on the fastest DC chargers.  That's likely going to be a bit longer than trips in the Telluride, but not by much.  We haven't taken a trip that requires topping up at a fast DC charger yet.  There are quite a few trip planning tools out there - ABRP app for one (A Better Route Planner) - and I've planned a few hypotheticals.   I'll let you know about how that goes that in a future post. Full disclosure - we still own the Telly.  It has 3 row seating, hauls a lot and is best for road trips where we take the dog.  But, for all our day trips, it's the Ioniq that we go to.

So, that's the first 1200 miles.  So far, tons of fun!