How We’re Charging EVs at Level 2’s 19.2-kW Maximum at Our Office

EV charging rates are often referred to by their simple Level 1 (120V), Level 2 (240V), and Level 3 (400V and up DC) classifications, but within those categories can be a wide span of charging rates. Level 2, for example, can range from a 6.0-kW ChargePoint hookup you might encounter in a parking garage to the maximum rate of 19.2 kW. If you own an EV, you want to be charging at home as much as possible; it’s more convenient and far cheaper that way. And we think the sweet spot is the ability to recharge your vehicle’s battery roughly overnight: call it in 10 to 12 hours or so.

For many EVs with moderate-size battery packs, this is possible with mainstream home-charging options, such as the ones featured in this roundup. But for vehicles with larger packs, such as the 131.0-kWh Ford F-150 Lightning, the 128.9-kWh Rivian R1S or R1T, or the 112.0-kWh Lucid Air, you’ll need substantially more juice for anything close to an overnight charge. For example, the charge time for a Lightning using a 6.0-kW outlet is roughly 24 hours, and a Hummer EV with its gigantic 212.7-kWh pack would take almost 40 hours.

How Charge Rates and Times Are Calculated

A quick refresher: The rate is simply the power output, or voltage times current, e.g., 240 volts and 40 amps equal an output of 9600 watts, or 9.6 kilowatts. And an electrical circuit can run continuously at 80 percent of its rated capability, so a 50-amp, 240-volt circuit is required to be able to charge at 40 amps or 9.6 kW. To estimate an EV’s charge time, take the battery capacity, add 10 percent for losses, and divide by the charge rate.

The long charge times with some of these latest big-battery EVs on the 6.0-kW ChargePoint units we have at our office caused us to search out a replacement for the two Tesla Wall Connectors we also have at our office, both of which were wired to support 19.2-kW charging on the Model S, an option Tesla has long since discontinued. While we’ve used a Tesla-to-J1772 adapter to charge non-Tesla EVs, that connector is only rated for charging at half the 19.2-kW maximum.

We landed on the Porsche Wall Connector, which sells for $1586. Expensive, yes, but there aren’t that many options for the fastest Level 2 charging. Ford’s Charge Station Pro goes for $1310, Lucid’s Connected Home Charging Station for $1200—both which support bidirectional charging. Clipper Creek is the rare third-party choice, and it goes for $2195. And the Porsche unit is the only one with a display on it, the same 5.0-inch touchscreen interface found on Porsche’s optional portable charging equipment, which is a $1120 option when purchasing a Taycan.

We were hoping we’d be able to view our charging remotely through the My Porsche app, but it turns out you have to be charging a Porsche that’s in your account to do so. We instead view the energy use on the screen to track EVs’ efficiency and can look back through previous charging activity if necessary. There’s also the possibility of connecting to the charging unit’s own hotspot to view activity, although we haven’t yet been successful in making that work.

Try This at Home?

To be able to charge at the maximum 19.2-kW rate, three things must align: your house must have a dedicated 100-amp circuit for EV charging, your charging equipment has to have the capability, and the vehicle must be able to accept it. For example, the Hyundai Ioniq 5, our 2022 EV of the Year, has a 10.9-kW onboard charger. So, it can’t charge at a higher rate than that on a Level 2 outlet no matter what charging equipment is installed. To be able to charge a Porsche Taycan at the maximum rate, you have to select the $1680 option for the 19.2-kW onboard charger when ordering, or there’s the possibility to retrofit it later.

But, when all of these things align, the charge times are impressive: a Taycan with the large pack can be charged from empty to full in under five hours, a Lucid Air in about 6.5 hours, and a F-150 Lightning or Rivian R1S or R1T in about 7.5 hours.