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 higher DC) classifications, but within those categories can be a wide range of charging rates. Level 2, for example, can range from a 6.0-kW ChargePoint outlet you might encounter in a parking garage to the maximum rate of 19.2 kW. If you own an EV, you want to charge as much as possible at home; it’s more convenient and much cheaper that way. And we think the best is the ability to recharge your vehicle’s battery roughly overnight: call it in 10 to 12 hours or so.

For many EVs with moderately sized battery packs, this is possible with mainstream home charging options, such as those featured in this roundup. But for vehicles with larger packs, like 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 significantly more juice for anything close to ‘ an overnight charge. For example, charging time for a Lightning using a 6.0-kW plug is about 24 hours, and a Hummer EV with its gigantic 212.7-kWh pack will take nearly 40 hours.

How charge rates and times are calculated

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

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

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

porsche wall socket

Car and Driver

We were hoping we’d be able to see our charging remotely through the My Porsche app, but it turns out you need to charge a Porsche that’s in your account to do this. Instead, we see the energy consumption on the screen to track EVs efficiency and can look back through previous charging activities if needed. There’s also the option to connect to the charging unit’s own hotspot to see activity, although we haven’t managed to get it to work yet.

Try it at home?

To be able to charge at the maximum 19.2kW rate, three things must match: your home must have a dedicated 100-amp circuit for EV charging, your charging equipment must 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. It therefore cannot charge at a higher rate than that on a Level 2 outlet, regardless of what charging equipment is installed. To be able to charge a Porsche Taycan at the maximum rate, you must choose the $1680 option for the 19.2-kW on-board charger when you order, or there is the possibility to adjust it later.

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