One Year and 11,000 Miles Driving an All-Electric Vehicle (EV)

By Michael Coppola
and Nancy Williams

Many people ask me questions about my new all-electric Vehicle, a Ford Mustang Mach-E. They stop me in parking lots, at the beach, or even on the road! This is a breakdown of the main points of owning and operating an EV and the impact I believe this market will have on Climate Change.

One of the first concerns I hear is about charging the battery and the car’s miles of range. Charging both at home and on the road has worked out well, however an understanding of the battery technology currently being used will help keep your EV running at its best. It's really no different than knowing what keeps your ICEV running its best. All batteries are degraded by heat, both by an external heat source and self-generated heat from charging and discharging. Just like your cellphone, you must protect your car’s battery from overheating. What that means for an owner is deciding how you charge to protect the battery while achieving the results you require for the kind of driving you are doing. 

EV batteries are set up to charge at different rates depending on the amount of charge that is on the battery. If your battery is very low,  say under 20% the first part of charging will be slow. Charging goes faster once the amount of charge increases. Also when the amount of charge gets above 80% the charging rate will slow down. These slower rates are designed to protect the battery, so how much charge is on the battery will effect the rate of charging. 

There are general guidelines that all the EV manufactures have for the most effective charging. My Mustang Mach-E with the 68KWH battery pack is listed with a maximum range of 230 miles. But the guidelines for this type of battery are to stay between 20% and 90% charge. So, for some trips you may want to limit range between charges to 180 miles. Charging slowly using a low voltage and amperage circuit will produce the least amount of heat and thus result in the longest life of the battery. You can use faster charging occasionally and also charge above 90% but the more you do the more the battery degrades. Ford does have a long warranty on its battery so it is unlikely you will need to replace the battery in the life of the car regardless. The next generation of EV batteries, which are beginning to be used, will have different guidelines. We will address that later on in the article.

There are a few kinds of charging methods so let’s go over them:

Charging from typical outlets at home

Ford provides an outlet cord that you can charge from an ordinary home outlet (120v 15amp) and a higher amp plug (240v 50a). My driving between 15 and 40 miles a day meant I could easily recharge back to 80%, roughly 200 miles of range using a 120v 15a outlet in my garage overnight. You only get 4 miles added per hour but there was always plenty of time to charge. 

The 240v plug provided is for a 50a outlet, so if you have a 240v 30a outlet you will need an adaptor, which I bought online for $35. Charging at 30 amps puts on around 20 miles per hour. So, if you travel 150 miles a day you can put back that longer range in less than 8 hours. If you have a 50amp outlet you will get about 25 miles per hour of charging.

For long trips there are many charging stations available with a wide range of costs and speeds and there are many ways to find them. EV manufactures provide phone apps and free apps are also available to locate and determine the status, type and, available of chargers in an area. We like PlugShare because it’s up to date and has reviews from users. A mapping feature gives locations either in your area or where you are going.

The typical types of connectors at charging stations:

1. There is one for older vehicles that use a connection that is not used in new models called ChAdeMO which is a 50 KW DC charger. It is a relatively slow fast charger.

2. Level 2, a 240v 50a charger called J-1772 that can only add about 25 miles of range/hr. These chargers are found at parks and hotels, where a long stay of up to 3 hours or overnight would be expected. They are used on all new EV’s.

3. DC fast chargers located usually at a store or mall have power ratings from 50KW to 300 KW. The connector is labeled CCS/SAE.  The higher the KW the faster it will charge. These take anywhere from 15 minutes to an hour to charge your EV depending on how much range you need to continue on. On long trips, a stop of that duration is an ordinary thing, time to use the facilities and get a snack.

4. Tesla has their own charging stations but with an adaptor they can use the other types.

All EVs have a regenerative braking system that allows the battery to be recharged when the car slows down. The Mach -E has “one-pedal mode” which means that when you back off the “gas” pedal the motor turns into a generator and sends a charge into the battery. It is charging the battery, and at the same time the resistive forces that are produced apply a braking force to slow the car.  The one pedal mode provides for the greatest number of regenerative events. One can choose not to use one-pedal mode in the Mach-E but even in that case some of the breaking energy is sent to the battery by the regenerative mechanism.  You always have the option to apply the brakes with the brake pedal in all modes including one-pedal operation. The Mach-E has 3 driving modes which affect how aggressively regenerative braking is used. The unbridled mode is the most aggressive. This extra charging capacity changes the calculation of the available range. 

Calculating the costs of EV charging

To calculate the cost of charging at home you need to know what you are paying per kilowatt hour (KWH). Florida electric rates are low compared to many other parts of the country so the cost could be more for where you are located. Our total rate per KWH is 11 cents (Electric rate has increased as of 12/02/2022 to just under 14 cents/ KWH, mostly due to fuel surcharge increase. My records show that adding 150 miles uses 14 KWH. So, at 14 cents per KWH, it now cost me $1.96. 

In addition, Duke Energy has an EV program that takes $10.00 off my monthly bill if I agree to charge during off-peak hours, which are 10 AM to 6 PM and 9 PM to 5AM. They even allow me 2 times a month that I can charge outside those hours.  The Ford software that I use to control the charging allows me to set the time it charges and the percent of charge where I want it to stop charging. The app records the miles of range added and the KWH consumed. If I were to drive 1,000 miles a month it would come to $10.27, (now $13. 06). But with the $10 credit it only comes to $.27, (now $3.06).  Charging during off-peak hours helps balance the electric load and allows the utility to operate its generating stations more efficiently. When they run more efficiently, they use less fuel.

Are there other costs to consider as an owner of an EV? Simply put, other than tires and windshield wipers to wear out, there is little maintenance needed over the life of the car.

Long distance trips

Our first long distance trip was 22 days long, 3,850 round trip miles from Tampa Florida to Rockland Maine. This was our first trip where we would need to charge outside the house, so I did have some "range" anxiety.  With respect to the quality of ride and comfort, the car is superb. There was plenty of pickup and no problem climbing the hills in Vermont.  The Blue Oval cruise control which drives the car and has accident-avoidance technology worked extremely well. It helps avoid driver fatigue. The accident-avoidance technology saved us from a possible accident stopping and steering the car around a car that had stopped suddenly on an interstate highway.

Finding a charging station was much easier than we had expected. It’s a good idea to have the phone-app from each charging service and set up your payment methods ahead of time. We have the apps for ChargePoint, Evgo, Shell Recharge, none of which require membership and Electrify America which membership came with the purchase of the car. There was little effect on travel times since high-speed DC charging hardly gives you time to use the restroom! There is however some inconvenience if it is raining or very hot because the stations are not sheltered, and the availability of chargers in very rural areas is sparse. 

The cost to charge ranged from free to 42 cents per KWH. Total cost to travel the 3,850 miles was $208. Ford gives free membership to the Electrify America charging network plus 500 free KWH. Other car manufactures give two years of free charging. The membership in the Electrify America Network gives you a reduce rate of 32 cents per KWH from the non-member rate of 42 cents per KWH. The actual out of pocket charging cost for this trip was $28 because of the free KWH's

Although you do not need your charging cable to charge at the charging stations it comes in handy if you are visiting a relative, because you can plug into any 120v outlet and charge overnight.  We enjoyed finding free charging stations at the parks and town centers we wanted to visit. They were invariably the slower level 2, 240v 50a chargers but if you are visiting for a few hours, you can add 50 miles of range.

On the new batteries coming to all EVs

A newer version of lithium-ion battery is being introduced, (LFP) that will be available in many of the EV's that are coming to market including the Mach-E. It has several advantages over the older generation of lithium NCA and NCM batteries. The LFP cost less to make, reducing the cost of the vehicle; its useful life is four times that of the older generation; it can be charged to 100% and it can be fast charged with out degrading the battery. It has two minor disadvantages. It is not as energy dense so its maximum range is about 10 miles less for the equivalent size older generation battery and it cannot accelerate the car 0 to 60 in under four seconds. The mileage difference is negligible and as long as you do not want the very fast acceleration it will be fine. Electric motors generate large amounts of torque and are very efficient, so you still have plenty of hill climbing and passing power. 

How to measure and compare efficiency of EVs vs. ICEV's

The efficiency of a system is measured by how much energy you put in and how much work you get out. The best way to determine which is more efficient is to calculate the distance each can travel on the same amount of energy. This is done by calculating the amount of joules of energy in a typical gallon of gasoline. You then convert the joules to KWH. It turns out that there are 33 KWH of energy in a gallon of gasoline. EV's will get at least 2.5 miles per KWH and up to 6 miles/KWH depending on battery size, the number of motors used and driving style and conditions.  If we take a midpoint of 4 miles/KWH, and multiply it by 33 KWH, the equivalent of a gallon of gas, we get 132 miles/gallon. If you search for the mpg of Cross-over SUV’s, I doubt you will get mpg anywhere near that amount.

The environmental impact of EV vs ICEV

Twenty-seven percent of all greenhouse gasses in the atmosphere from man-made sources come from the transportation sector. Although we still produce the majority of electricity from fossil fuels, all studies show that even if the EV was using electricity made by burning coal, its carbon footprint, from "the mine to the road" is smaller than any ICEV. One issue that has not been considered when comparing these two technologies is the climate impact of all the heat generated by ICEV. That heat disperses into the atmosphere and heats up the greenhouse gases.  One needs only to roll down the window when sitting in traffic to see how much heat they produce. EV's produce an insignificant amount of heat.

Today’s batteries have proven to be commercially and economically viable for trucks, cars, and construction/farm equipment. Also, electric trains have already replaced many diesel-powered trains. The replacement of ICEV's with EV's can have a big impact on reducing global greenhouse gasses and global warming. The future looks better from the seat of an EV and we are hoping to see more of them on the road.

References

How Can We Decarbonise Trucking? | Engineering with Rosie Live Ep 11

Sources of Greenhouse Gas Emissions