Recently began looking for a new car and decided to investigate the EVs. Unfortunately, the industry has yet to implemented clearly defined markers for comparison purposes. My goal here is to explain how I came to select an EV car. I’m very happy how everything worked out and believe I made a good technical and financial decision based on my needs. I hope this helps you and perhaps you can add your own decisions formulas.
So, these cars come in 3 main configurations.
Hybrid EV vs Extended Range EV vs Fully Electric EV
Hybrid EV, a gas engine driven car that also powers a small generator. The electric motors assist and or powers vehicle directly through the common mechanical drivetrain. Great for city, limited electric range and comes with no plug-in charging. When gas runs out this unit will be limited in range and speed automatically drops down. Hybrids Explained - What’s a Plug-in, a Mild, or an ER-EV?
Extended Range EV is a full electric car with an on-board generator. It solely operates on electric and can generate electric power to store in the battery through its on-board gas engine generator. Because of greater battery capacity over the Hybrids it offers longer (electric only) commutes and has a L2 plugged in port. Braking forces regenerate battery, and when gas runs out this unit will be limited in range only. In fact, you can add 40 miles driving range to Nissan Leaf with Enginer's add-on battery pack.
Fully Electric EV is a battery only car. Great for even longer (electric only) commuting and requires to be plugged in. Braking forces regenerate battery, since this does not use gas, its range is limited by battery capacity.
In my location the government offers rebates based on how green and what price range your EV locates. I’m sure there are other criteria. So, based on my daily commute of 80 miles and budget, I decided on the Extended Range EV. Now the concern is how to select the right car with no datum to work from. I found the dealers to be wishy washy on performance, so I made my own formula. Keeping in mind I have a good commute. I started with the Volt and looked as much information as I could find at its competitors. This was the type of information I could gather.
What I found is as the engine size goes up the battery capacity goes down.
- Year - 2018
- Model - Volt
- Battery Capacity kWh - 18.4
- Engine Size - 1.5L
- Battery Regeneration - Yes
What I could readily identify for all Extended Range EV cars was battery capacity. This is a gem of intelligence because one can now compare EVs on a level playing field. One could also determine electric range and costs to operate fully electric. The formula is a rule of thumb only as I cannot determine any peripheral electronic consumers.
It takes about 15 HP for a midsize car to main 60 mph. That means no external forces added and at a nominally mild temperature. Wind and cold would lower performance. Using this for all vehicles should provide for a pretty good comparison point. (Rule of Thumb only)
Volt battery capacity is 18.4 which is 25 hp/hr. The hp required to maintain 60 mph is 15, so 25/15 = time of driving at 60 mph = 1.7 hours. This was the highest result I could find in all my EV car comparison. Distance driven is 60 x 1.7 = 102 miles, albeit this is obtainable with influences like regenerative braking, long steady declines and slow speeds.
To take this a step further, our electric charge costs are 7.7 cents per kWh during off peak times. Therefor the cost to charge battery is 7.7 x 18.4 = $1.42.
I hope with this technical review this may help you select your Ev. Also see: Is Chevy Volt an EV, Hybrid or Both?