Apologies to MC Hammer….
So you need to charge your rolling battery. We discussed in the previous post that a bigger charger can add more miles, in the form of kilowatt-hours (kWh), than a smaller charger. Chargers sort-a, kind-a come in three sizes called L1, L2 and L3. L means ‘level’.
Each level can charger faster than the one below.
L1 is your regular ol’ household outlet. That’s 110 volts at 15 amps. That’s 1.65kW, or, not much. I know my arithmetic is correct; 110 times 15 IS 1,650. But many web pages I see describe L1 having more like 3.7kW. They may be assuming 30 amps. Audi says an L1 charger can add 80 percent, 76kW, in 90 hours. I think that means they are assuming 0.84kW. Whatever… there’s clearly not a lot of ‘go’ in that plug.
A lot of chargers listed on PlugShare are L1. It’s helpful to set your filters to ignore these chargers. (See below.)
L2 uses more voltage and more amps. So way more kW. We have a 30 amp, 240 volt outlet in our garage. That’s 7.2kW. We need 76kW to go from empty (20%) to full. It should take 10 hours. And indeed, Audi says 9 hours on an L2 charger will fill the tank.
Both L1 and L2 are alternating current (AC). You know, the normal household stuff, but with a little more kick in the L2 case.
L3 is direct current, or DC. We generally don’t have this stuff in our homes. At least not in any wall plugs. ElectrifyAmerica and others are building nationwide networks of L3 chargers. EA has 50kW and 150kW chargers in metro areas and 150kW and 350kW chargers along major interstate highways.
Three-hundred and fifty kilowatts is, well, a lot. Fifteen minutes on a 350kW charger will deliver 87.5kW or more than we need to go from 20% to full in the Audi e-tron. We can cut our refueling time in half. Sort-of…
The other eighty percent
We already know that most EVs think 20 percent state-of-charge (SOC) is empty. L3 chargers slow down when the SOC reaches 80 percent. I’m not sure why. Apparently, L3 charges approach L2 speeds when the battery gets to 80% SOC. If the cost per minute of an L3 charger is higher than that of an L2 charger, it might be cost-effective to switch at 80% SOC.
A 350kW L3 charger can push the e-tron battery from 20% to 80% in just under 10 minutes. And that’s about 115 miles. If you had enough chargers along a route, you could drive 115 miles, charge for ten minutes, drive 115 miles, charge for ten minutes, etc. I’m not sure that’s better, but you are supposed to take frequent breaks!
You can plug that
There are a bunch of charger plugs out there. The one, or two, you want are dictated by your car. Tesla has their own adaptor. Ignoring that, you’ll find three plugs on public charging stations.
They look like this:
 |
 |
 |
| J1772 | CHAdeMO | SAE Combo CCS |
The J1772 plug is very common either by itself or in the CCS combo plug. Teslas have their own super-chargers and plugs, but they can use the J1772 with an adaptor. The e-tron uses the CCS adaptor. Which means it can also use the J1772.
The J1772 is an L2 plug. L3 chargers, other for non-Teslas, use the CCS plug. That bottom part of the CCS is the DC connector. The good stuff…
Nissan Leafs use the CHAdeMO plug. It does not fit the e-tron.
Bottom line
L3 is best, L2 is second best, L1 won’t cut it while traveling. The difference between L3 and L2 is substantial. Use L3 when possible.
