It depends on the cost of electricity where you live if you are charging at home. Public access chargers vary greatly, some being free, some being free for an hour or two, some having crazy expensive costs either by kWh or time. You can look on PlugShare app in your area to get a feel for it. The standard battery has a capacity of 52.7kWh and the extended range is 84.3kWh. Multiply that by your electric rate for the cost. Some utilities even have a flat monthly cost where they also install a charger.
I have a charger at home. For me to charge the standard Slate battery from 0% to 100% would cost $6.22 and the larger battery would be $9.95. Taking the standard range of 150miles that would require 5 gallons of gas assuming 30MPG which would cost about $15 here. You also have to consider no oil changes, air filter, spark plugs and all of the other maintenance that is required with a gas engine.
For public charging the internet shows the national average is $0.45 per kWh. The national average for regular gasoline today is $3.16. Assuming a 25 MPG car and the Slate at 150 miles per 52.7 kW, the gas car costs 12.6 cents/mile and the Slate at 15.8 cents/mile. Change to at home charging at $0.13/kWh and the Slate drops to just 4.5 cents/mile.
Add in the estimate average for maintenance per mile: EV $0.06 and ICEV at $0.10, a 4-cent delta, and EV on public fuel vs. ICE and the running cost is about even.
Charge at home and the EV has a $0.12 advantage.
More math. At 12,000 annual miles, the worst on public fuel the EV saves just $100/year vs. ICEV and on home electricity the ICEV costs $1,450 more/year than the EV.
E90400K and FL4XE explain very well that the best case for EV ownership is if you can charge at home regularly and only use public DCFC for road trips.
Both very good examples but you should look at your local electricity rates. If you have cheaper rates, say from 9pm-7am, you could save even more.
