Public charger efficiency

[MikeRTX]

Just wondering, if I have to use public chargers while traveling, what kind of efficiency can I expect?

And do public L2 chargers typically deliver the same amount of charge/range as a L2 SC? If, say, an EA charging station is delivering 150kW, is it giving me the same amount of charge (or miles of range) in a given time as a SC station with equivalent kW? (Yeah, I'm no electricity whiz.)

 

[jjrandorin]

Your asking a couple different separate things here.

Without going into a bunch of detail, there is no such thing as a "level 2 supercharger". Level 2 charging for Tesla model 3s and Ys does not go any faster than 48amps (for LR or performance), or 32amps (for the SR in your signature). The public level 2 chargers are called "destination" chargers in Tesla land, but they are AC chargers and the same chargers people have in their garages if they have home charging and bought a wall connector.

At a given amps, its going to be "roughly" the same. 32amp charging at your house and 32 amp charging at a public charger is going to be roughly the same, except the public charger might be at a slightly lower voltage due to being on commercial power.

The EA station in your example would be a DC / FAST charger (150kW), and it would be roughly similar to a supercharger with equivalent kW.

As for "what efficiency can you expect" a Level 2 charger (that your car maxes out at 32amp) is going to be roughly the same at home as anywhere else you plug into it.

 

[Gauss Guzzler]

It's not "efficiency", it's speed. The kilowatt rating is speed and your car's kilowatt-hour rating is capacity. Compare the charger's rating to your battery's capacity for a rough idea how long it would take to recharge.

A 7.5kW charger will take ~10 hours to fill a 75kWh battery.
A 75kW charger would take ~1 hour to fill a 75kWh battery, in theory.
A 150kW charger would take ~1/2 hour to fill a 75kWh battery, in theory.
etc.

In practice, the charge rate will slow dramatically as the battery approaches the 80%-100% range but the math above can help you estimate the time needed for a partial charge. You'll find that a 150kW charger may bump you from 10% to 60% in less than 20 minutes, but to go from 10% to 100% might take 90 minutes. Tesla's navigation will guide you toward the optimal partial-charging strategy for minimum downtime.

 

[ItsNotAboutTheMoney]

Just wondering, if I have to use public chargers while traveling, what kind of efficiency can I expect?

And do public L2 chargers typically deliver the same amount of charge/range as a L2 SC? If, say, an EA charging station is delivering 150kW, is it giving me the same amount of charge (or miles of range) in a given time as a SC station with equivalent kW? (Yeah, I'm no electricity whiz.)

You mean V2 SC?

EA 150kW chargers are 375A max. They're rated at 400V.

_Some_ of their 350kW chargers were actually 350 amp max. The 350kW chargers are rated at 1000V, but some can do 500A, though still 350kW max.

At any time while charging the charger and car can limits the amps. The charging voltage is the battery voltage.

 

[MikeRTX]

Thanks, guys. I've always heard that public chargers are "slower" than Tesla SC's, making other brands of EV's generally have to take longer for a given amount of charge.

I know it's more a function of the capacity of the charger built into the vehicle, but the charger station also has to deliver lots of power to get equivalent levels of charge, and I've been under the impression public chargers like EA,Blink, etc., don't deliver like Tesla SC's.

So, comparing, say, a 150kW EA to a 150kW SC for my model 3, will they charge from 20-80% in about the same amount of time? Or is there something in the electronics that makes them different?