Sparks's Journal

A look at electric vehicle charging.

I’ve been driving an electric vehicle (EV) (Chevrolet Bolt) for a little over a year now and have now gotten used to the way it drives and the lifestyle of charging. Getting behind the wheel of a internal combustion engine (ICE) vehicle is now quite disturbing. The noise, the handling, the inefficiencies… they are all quite annoying.

One question I get about owning an EV is charging it. Many people try to make the comparison of filling up a ICE vehicle with gasoline or diesel fuel with charging their EV. While both are adding potential energy to their vehicle, most people neither fill up their vehicles daily nor do they have this capability at home thus they only fill up every few days when they get low. With an EV, you don’t wait until you are empty; you simply plug your vehicle in every day when you get home and charge up! Because your vehicle is mostly sitting parked, it can easily be charging while it isn’t being driven, so it’s always ready to go.

Types of charging

Charging rates are measured in kWs, miles per hour, and time to finish. Depending on what information you are interested in, these different rates are important.

There are basically three types of charging that are available to modern EVs (not to include the Tesla vehicles which have their own charging environments and lingo). Each of those levels charge the vehicle at different rates as each rate is suitable for different situation.

Level 1 charging

Level 1 charging is the slowest charging method. This is basically a charger that plugs into a regular 110V household outlet and consumes 8 or 12 amps (configurable for the Bolt). At this rate, you’ll likely be charging at a rate of ~4 miles per hour. If you are charging your vehicle while you are at work (think 9 hours) or while you are home for the evening (think ~12 hours), you’ll put 36 to 48 miles of range back into your battery or a combined 84 miles per day if you can charge at work and home.

Depending on your commute to and from work, this might work well for you. We used a Level 1 charger for several months until we just decided to go with something a bit faster, just because.

Level 2 charging

Level 2 charging is a good medium speed charging method. It requires 220V of AC power instead of the standard 110V outlet, but can give you a much faster charging experience.

Our charging station is setup to deliver approximately 7.5kW to the vehicle and the vehicle’s onboard inverter controls how much of that energy it will use to efficiently charge the battery. Now we’re charging in the range of 15 miles per hour or even faster.

Level 3 charging

Level 3 charging is a very fast, direct DC charge to the vehicle’s battery. The charger will only charge the battery to roughly 80% to prevent damaging the battery, but it can bring an empty battery to almost charged in just under an hour. For me, that’s like adding around 270 miles to my battery in less than an hour!

Cost of operating

So what is the cost difference between operating my electric car and my ICE car? Well, here are some numbers for you:

In the month of January I logged 1960 miles on the EV at a cost of around $59 (based on rates set by BG&E). Had I driven those same miles in my ICE vehicle, which gets around 34 miles to the gallon, and paid an average of $2.65 per gallon, it would have cost me roughly $152 in gasoline (not including oil changes and other ICE maintenance that my EV doesn’t have).

If I factor in that I generate some of my own electricity using solar panels, and that I get SRECs for generating that power, the cost for operating my EV goes down even more.

Range

Some of the EVs from previous years had a rather short range of 100 miles or so. The Bolt we purchased has a range of 300 miles which means we don’t really look for chargers along our journey unless we’re going a long ways away. I suspect the next versions of these EVs will have an even better range as battery technology continues to improve.

Sparks's Journal

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