EV Basics 4/9/22

EVs (electric vehicles) are here and growing in popularity. The biggest positive is that from an operational perspective they are zero carbon dioxide emitters if the source of the electricity for charging is renewable (solar or wind, for example, which can be elected through electricity providers). EVs are more Man-made Global Atmospheric Change friendly than vehicles with internal combustion engines.

We have 3.33 EVs in our family: our daughter and son-in-law, Sue's niece and her husband, and my nephew and his wife each have an EV. As seen below, our son-in-law gives his EV a big "thumb's up."

EV prices are roughly proportional to their driving range, mainly because the batteries are the significant cost factor. After you get past the initial sticker shock and considered the economic and ecological benefits, understanding driving range and charging options is very important. No longer will you be able to pull into the next convenience store or get off the interstate at the next exit to fill-up in a few minutes. When you own an EV, you need to plan much farther ahead.

Commercial and public charging options continue to grow, especially in more populated areas and along interstate highways. Charging locations are easily found via Google. Tesla has a very large and widely distributed system of Super Chargers (Level 3) and Destination Chargers (Level 1 or 2) that the car will identify via the on-board screen. To understand difference in charging levels, we need to understand more about the charging process.

EVs are DC (direct current) systems but commercial electrical current is AC (alternating current). The On Board Charger (OBC) located in the EV (not in the charging cord or the boxes that looks like a electric fuel pumps) is the brain in the charging process. It converts AC to DC current and charges the battery and/or passes incoming DC current onto the EV's batteries. OBSs operate at one or more or three different charging levels. These levels are actually ranges with some OBCs operating at the faster end of a range, others at the slower end, and some in the middle. The OBC also determines when the battery is "full" and ends the charging process.

If a OBC can operate at Level 1, only 3 to 5 miles of range per hour is added to the EV's battery. Plugging an EV into a standard 120 volt wall receptacle at home with overnight charging is common practice at Level 1. The following photo shows the charging cord (that came with an EV) hanging in a home garage and plugged into a standard 120v receptacle.

If the OBC can operate at Level 2, the EV can be charged using a 240 volt AC current, for example commercial chargers or a 240v receptacle at home (240v is used by home electric kitchen stoves and electric clothes dryers and use special receptacles). 12 to 80 miles of range per hour will be added to the EV's battery. Our son-in-law and daughter have a dedicate 240v line with outlet in their garage to charge their EV. It is sourced by solar roof panels.

OBCs that can operate at Level 3, the faster charging level, are typically found in EVs with high mileage ranges. The OBC in those EVs are the fastest because they can accept 400 to 900 volts of DC current from a charger, adding 20 or more miles of range PER MINUTE to the EV's battery. Tesla SuperCharging stations and other "Fast Charging" stations are designed to work with Level 3 OBCs. However, Tesla SuperChargers are not to be confused with Tesla's "Destination Chargers," which are designed for Levels 1 and 2 charging. The benefit of a Tesla SuperChargers is they provide about 200 miles of range in 30 minutes.

Most OBCs that can operate a Level 2 will also operate Level 1 if the current is 120v rather than 240v. Similarly, most OBCs that can operate at Level 3 also will automatically operate at Levels 1 or 2, though an adapter maybe needed for the plugs on EV cords with Level 3 OBCs.

You may have noticed that at the top I indicated, "...we have 3.33 EVs in our family...," but to this point in the blog entry I have only mentioned three. The .33 is a plug-in hybrid SUV that we purchased in the process of downsizing from two to one vehicle. This small SUV is designed operate as an EV for the initial 40-50 miles, after which it automatically becomes an HV (hybrid vehicle). It also can run totally on the gasoline engine and will simultaneously add charge to the battery. This plug-in hybrid matched our driving habits - 500-600 miles a month 90% of it around town. We essentially operate as a EV and charge at night every two to three days at Level 1 via a dedicated 120v circuit in the garage. We can count on one hand the number of times we fill the 14.5 gallon gas tank in a year. Some of the mileage in hybrid mode is purposeful - to keep the gasoline engine in running order.