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> With an EV you drive to the supermarket, plug in your car to the destination charger (22kW), do your shopping, disconnect and drive home. That's fine if your

by jjk166 5y ago

> With an EV you drive to the supermarket, plug in your car to the destination charger (22kW), do your shopping, disconnect and drive home. That's fine if your destination is 5 miles away, it doesn't work when your destination is 500 miles away. Long distance travel represents a small portion of total trips, but it's frequent enough that if you can only afford a single car, it needs to be able to make those trips. Fast charging is a hard requirement for mass adoption. Maybe it doesn't need to be quite as fast as filling up a gas tank, but it needs to be short compared to the time spent driving. 20 minutes for 200 miles might be acceptable, 30 minutes for 60 miles is definitely not. Once the infrastructure is there, I'm in. And as that infrastructure becomes more common, EVs with shorter ranges (and thus cheaper batteries) become viable. Right now there are about 5,000 fast charging stations in the US, for comparison there are 136,000 gas stations.

chipsa 5y ago
Small EVs are averaging around 3.5-4 mi/kWh. 60 miles would therefore be around 18kWh. You're postulating a mere 36 kW charger there. We actually have 150 kW chargers as being common, with 350 kW being reasonably often seen. That said, not all cars will necessarily reach that level. Neither of my EVs would see a benefit from the 350kW chargers, as it requires a 800V battery architecture. But expect cars in the next 10 years to be generally 800V systems. So you're looking at 1000 mph of charging speed with 350kW chargers. There may be limits such that cars don't actually get all 350kW, but... yeah, we're already beyond your "acceptable" level. It's just not evenly distributed. And yeah, there's fewer fast charging stations than gas stations, but if most daily charging is done at home, you don't need as many as gas stations. 5k is probably too few, but 136k is almost certainly too many.
- jjk166 5y ago
  No, I'm saying the 36kW charger is unacceptable. A 150kW charger is the bare minimum that might be acceptable and you're adding about 10% to your travel time for recharging. 350 kW is still about an order of magnitude slower than filling an equivalent sized gas tank, but is probably fast enough. And of course the fast charging capability is useless if it isn't along the route you need to travel. While we may not need quite as much coverage as gas stations, you definitely need regularly spaced stations along major routes like the interstates. It honestly doesn't even need to be a huge number - 4 stations spaced every hundred miles along the interstate system would only be 1900. It would take 27000 stations to get 1 for every hundred miles of paved road in the US, but that can come later as demand increases.
  - chipsa 5y ago
    Unsurprisingly, 150kW appears to be becoming the standard for 400V architecture. 36kW chargers don't exist. Fast chargers are proliferating along major routes. The only major area that doesn't have regularly spaced fast chargers is the northern plains area (I-90, I-94).

by jjk166 5y ago

chipsa 5y ago

Small EVs are averaging around 3.5-4 mi/kWh. 60 miles would therefore be around 18kWh. You're postulating a mere 36 kW charger there. We actually have 150 kW chargers as being common, with 350 kW being reasonably often seen. That said, not all cars will necessarily reach that level. Neither of my EVs would see a benefit from the 350kW chargers, as it requires a 800V battery architecture. But expect cars in the next 10 years to be generally 800V systems. So you're looking at 1000 mph of charging speed with 350kW chargers. There may be limits such that cars don't actually get all 350kW, but... yeah, we're already beyond your "acceptable" level. It's just not evenly distributed. And yeah, there's fewer fast charging stations than gas stations, but if most daily charging is done at home, you don't need as many as gas stations. 5k is probably too few, but 136k is almost certainly too many.

jjk166 5y ago
No, I'm saying the 36kW charger is unacceptable. A 150kW charger is the bare minimum that might be acceptable and you're adding about 10% to your travel time for recharging. 350 kW is still about an order of magnitude slower than filling an equivalent sized gas tank, but is probably fast enough. And of course the fast charging capability is useless if it isn't along the route you need to travel. While we may not need quite as much coverage as gas stations, you definitely need regularly spaced stations along major routes like the interstates. It honestly doesn't even need to be a huge number - 4 stations spaced every hundred miles along the interstate system would only be 1900. It would take 27000 stations to get 1 for every hundred miles of paved road in the US, but that can come later as demand increases.
- chipsa 5y ago
  Unsurprisingly, 150kW appears to be becoming the standard for 400V architecture. 36kW chargers don't exist. Fast chargers are proliferating along major routes. The only major area that doesn't have regularly spaced fast chargers is the northern plains area (I-90, I-94).