Well since we're here..... I had to look it up. These are public charging rates, but I feel like we were paying about that rate when we left. It's very convoluted how much they charge you, so charging at night will probably be cheaper, but here it is.
Drivers in California may expect to pay
30 cents per kWh to charge on Level 2, and 40 cents per kWh for DC fast charging. At these rates, the same Nissan LEAF with a 150-mile range and 40-kWh battery would cost about $12.00 to fully charge (from empty to full) using Level 2, and $16.00 with DC fast charging.
So basically $0.10/ mile.
If you take a similar car getting 45 mpg, fuel has to be over $4.50/gal for the gas engine to be more expensive to drive
Charging at night could cut the cost in half, but either way its still possible for the gas car to be similar or cheaper if fuel prices aren't ridiculous.
Fwiw, the same charge would be $2.40 here