EV charging research

Charging speed (DOE AFDC). AC Level 1 runs on a 120-volt plug at about 1.9 kW, roughly 5 miles of range per hour. AC Level 2 runs on 240 V (or 208 V) at 7.2 to 19.2 kW, roughly 25 miles of range per hour, with residential units commonly up to 30 amps delivering 7.2 kW. DC fast charging goes up to 500 kW and delivers roughly 100 to 200-plus miles in 30 minutes.

Charging speed (ENERGY STAR). Slightly more conservative: Level 1 at 2 to 5 miles of range per hour and Level 2 at 10 to 20, with units wired to 50 amps charging faster. ENERGY STAR also states Level 2 is on average about 10 percent more efficient than Level 1 while adding roughly four times the miles per hour. Where two federal sources give different ranges, treat the spread as the honest answer.

Equipment and installation cost (DOE). DOE cites a Rocky Mountain Institute figure of $380 to $690 for a residential Level 2 charger and $0 to $900 for residential Level 1. National-lab research cited by DOE puts residential installation at $400 to $600 per connector for Level 1 and about $1,300 per connector for Level 2, excluding labor and permitting, and notes labor is the largest single expense in a typical installation.

Running cost (DOE). AFDC's worked example: at 10.7 cents per kWh with a vehicle consuming 27 kWh per 100 miles, cost per mile is about $0.03, and fully charging a 200-mile EV with a 54 kWh battery costs about $6. AFDC also notes actual residential cost depends on equipment, time of day and duration, and that some utilities offer time-of-use rates.

How to choose

Prefer .gov ranges over vendor single figures

AFDC and ENERGY STAR publish ranges because the honest answer is a range. A vendor quoting one number is simplifying to sell.

Note when two federal sources disagree

AFDC says about 25 miles per hour for Level 2; ENERGY STAR says 10 to 20. Both are official. Plan on the low end.

Separate equipment cost from installed cost

DOE's $380–$690 hardware figure excludes labor and permitting. Comparing it to a $959 installed average is apples to oranges.

Recompute the running cost at your own rate

AFDC's 3 cents per mile assumes 10.7 cents per kWh. Substitute your actual rate — the difference across the country is large.

Check the date on any incentive figure

The IRS publishes the exact placed-in-service window for the federal credit. Incentive claims without dates are unreliable.