[moltuae]

Originally Posted by MikkiJayne

I was reading about the new generation of 450KW charging stations recently and it just blew my mind. Most EVs appear to have 400V battery systems, so thats a charge current of over 1000 amps It needs a liquid-cooled connector which is just mental. If that much power escapes it will happily vapourise any inadvertently-connected human and pretty much anything else which is in the way. Its an entirely new paradigm to have that much elastictrickery in the hands of the general public so it'll be interesting to see how it pans out.

Also worth pondering - a typical 11KV local substation has a total rating of 1MW, so basically two of those chargers! To put half a dozen of them at a service station, Tesla-style, you'd need a dedicated 132KV industrial supply line and associated (large) substation. Ironically, that might be fine in the countryside where there's plenty of space and you can run new power poles, but getting that sort of juice in cities is going to be a real challenge. Its entirely likely chargers of this type will have to be one-to-a-site simply because there isn't enough infrastructure to support more, which backs up the queues for chargers scenario.

Interesting times

Wow!

I hadn't actually done the maths and I was thinking 450KW would probably be enough to charge many cars simultaneously. Still, it should be sufficient to charge a few cars simultaneously at slower charging rates.

I don't know what the charging rate of a typical EV is but, if we take a Tesla P100D, for example, which I believe has a 100kWh battery pack, it would take 100kW of energy for one hour to fully recharge it. Assuming a 400 volt battery pack, that's a 'mere' 250 amps!

Of course if you want to charge the same battery in 15 minutes (do any EVs charge that fast yet?) that would be 400kW @ 1000 amps!


At the other end of the scale, if my maths is correct, you could charge the same battery pack overnight (say 10 hours) using 10kW @ 25 amps, which would theoretically allow simultaneous charging of 45 cars from a 450kW supply.