Wake up full. Save about $1,360 a year over gas.

For most cars with the J1772 plug, the EVIQO Level 2 ($299 when we checked, on sale from $499): 40 amps plugged into a NEMA 14-50 or 48 amps hardwired, up to 38 miles of range an hour, app scheduling, a 25-foot cable and a 3-year warranty, the lowest price we found. For a Tesla or other NACS car, the Lectron NEXUS ($419.99): 40 amps, ETL listed to UL standards and ENERGY STAR, no app; EVIQO's NACS version ($480.99) adds the app. The Autel MaxiCharger AC Elite Home 40A ($559) is the smart pick with a hardwired 50-amp option.

Match the port on your car. Teslas and a growing number of newer EVs have the NACS (Tesla-style) port; most other EVs and plug-in hybrids have J1772. The charging speed is the same at home. If you might switch, buy for the car you have and keep an adapter for the other plug.

A 40-amp charger adds roughly 30 to 40 miles of range an hour, which refills a typical day's driving in an hour or two overnight. A 48 or 50-amp charger must be hardwired on a 60 or 70-amp circuit and only helps cars that accept more than 9.6 kW. Most people never notice the difference.

A plug-in charger uses a 240-volt NEMA 14-50 outlet (the kind for electric ranges and RVs), so you can take it with you when you move. Hardwired allows higher power and is often recommended outdoors. EnergySage puts the price difference in installation at about $100 to $200.

Not always. An ordinary 120-volt outlet adds about 5 miles of range an hour, roughly 50 miles overnight, which covers many commutes. Level 2 refills even a long day's driving overnight.