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Old 12-18-2016, 12:15 AM   #36 (permalink)
sendler
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This 350kW number is fun for them to throw around and get people excited about but no car can use this much charge rate. It would need a 1000v battery to keep the current down to 350 amps. And full liquid cooled contacts and cables. But it will be nice to have charge stations with the massive high kv grid connection and sub station needed to quick charge several cars at the same time at whatever the max rate they can take. I did read an article about the European qick charge start up that is accepting proposals for sites and the main consideration is access to high voltage power lines and easy access to major highway travel. And they all have grid scale Lithium battery storage units to smooth the demand. here is a post from the Leaf forum.
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350kW at 1000V. This was not mentioned. At 400V it is just 140kW. Slightly faster than Supercharger.
BUT that speed is only possible with liquid cooled pins in the plug. Without that extra it is less than 100kW.

1000V packs are big questionmark on small vehicles due to extra complexity.

Also charging at 350kW is not possible due to thermal limitations (car is not capable to extract heat
at that speed from the pack). Imagine at 90% efficiency 35kW of heat. Not going to work.
Even with absurdly massive AC compressor there is not enough surface area for radiators.

I've not even heard of patents about getting heat out of the car.
With my professional opinion, 350kW charging speed is not going to happen with normal cars (at least not within a decade).
I highly doubt 200kW (at least 10 minutes) will work within 5 years.

With buses, semis, ships - definitely possible.

Also another limitation of the lithium chemistry itself. 100kWh battery can do around 120kW (Tesla).
200kWh pack could do around 240kW. But 100kWh pack (no matter the voltage) will not charge at 240kW rate without
MASSIVE improvement. Voltage per cell would tip safe limit instantly.
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