First DC Station capable of charging at a rate of up to 350 kW, operational by 6/17?

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edatoakrun

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Sounds like EVgo might be planning to skip interim increases in kW from the ~50 at its existing stations, increasing charge rates all the way to ~350 kWh (and with multi-BEV charging capacity able to support a significant level of traffic) at least on some high-traffic corridors.

Today's press release:

EVgo Breaks Ground On The First Public High-Power Electric Vehicle Charging Station, Connecting Los Angeles And Las Vegas

EVgo, operator of the nation's largest network of public electric vehicle (EV) fast charging stations, today announced it has broken ground on the very first High-Power U.S. public charging station in Baker, California, home of the World's Tallest Thermometer. EVgo is turning up the heat on EV charging with a station capable of charging at a rate of up to 350kW. The new chargers being installed are seven times faster than any fast chargers currently available and represent a new level of convenience for EV charging.

When complete, EVgo's High-Power charging station at the site of World's Tallest Thermometer, will link Southern California to Las Vegas, furthering EVgo's position as the leading national fast charging provider. The High-Power Charger complements EVgo's existing fast charging stations throughout California and the U.S., allowing EV drivers to travel with confidence.

"EVgo is laser focused on the needs of our customers, and they want faster charging at more locations," said Terry O'Day, Vice President, Product Strategy and Market Development at EVgo. "The World's Tallest Thermometer High-Power station is an important step for the EV industry, as this new standard will open the EV market to even wider audiences. When this station opens to the public next year, EV drivers will enjoy a new level of freedom."

The World's Tallest Thermometer High-Power station will include four High-Power DC fast chargers capable of up to 350kW each, and can accommodate expansion of up to eight chargers in the future. The site will include a solar canopy to help power the chargers, as well as backup batteries. The High-Power chargers will be compatible with the two protocol standards used by all EV manufacturers, CCS and CHAdeMO. EVgo expects the project to be completed by June 2017...
http://www.prnewswire.com/news-releases/evgo-breaks-ground-on-the-first-public-high-power-electric-vehicle-charging-station-connecting-los-angeles-and-las-vegas-at-worlds-tallest-thermometer-300378564.html
 
Some 20 - 30 miles range per minute. Wow
I wonder what voltages are offered
I would never let a LEAF near that thing, but an EV with proper cooling would be brilliant.

Current Teslas have a Chademo adapter ...
This could be the technology that VW should spend it's $2B of diesel penalty money towards
 
SageBrush said:
Some 20 - 30 miles range per minute. Wow
I wonder what voltages are offered
I would never let a LEAF near that thing, but an EV with proper cooling would be brilliant.

Current Teslas have a Chademo adapter ...
This could be the technology that VW should spend it's $2B of diesel penalty money towards


I thought about that. Is there something onboard the leaf that would limit the charge rate to something the leaf could handle. That way we could still use the facility.
 
Wannabeleafowner said:
...Is there something onboard the leaf that would limit the charge rate to something the leaf could handle. That way we could still use the facility.
EVERY DC-capable BEV has a battery management system that controls DC Charge rates.

So every BEV that has DC CHAdeMO or CCS capability (Teslas, only if they have an adapter) will be able to charge.

And don't panic, it won't hurt your LEAF's pack any more (or charge it any faster) than any ~50 kWh DC charger would.

Of course, some BEV drivers have such severe battery anxiety, that they are afraid to charge with DC at all...
 
edatoakrun said:
Wannabeleafowner said:
...Is there something onboard the leaf that would limit the charge rate to something the leaf could handle. That way we could still use the facility.
EVERY DC-capable BEV has a battery management system that controls DC Charge rates.

So every BEV that has DC CHAdeMO or CCS capability (Teslas, only if they have an adapter) will be able to charge.

And don't panic, it won't hurt your LEAF's pack any more (or charge it any faster) than any ~50 kWh DC charger would.

Of course, some BEV drivers have such severe battery anxiety, that they are afraid to charge with DC at all...

Thanks for the info. Good to know. So much to learn about these things.
 
edatoakrun said:
Wannabeleafowner said:
Of course, some BEV drivers have such severe battery anxiety, that they are afraid to charge with DC at all...
That would not be me. I figure a couple times a year is fine ;-)

And joking aside, at least after a DC charge the car is liking moving again rather than stewing.
 
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.
 
arnis said:
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.

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.
I gather that newer Tesla SC has liquid cooling but most the network does not and it charges 60 kWh Tesla cars at up to 120 kW just fine. Liquid cooling gets them up to ~ 140 kW, for all Tesla cars.
 
arnis said:
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.
The inefficiencies of AC to DC conversion occur off board. So I believe that the DC charging of the battery is 98% to 99% efficient. At 98% efficient that would mean the amount of heat generated during a 60 kWh charge is 1.2 kWh. If the pack weighs 400 kg and has a heat capacity of 1.0 J / gC (a guess, iron is 0.45 and water is 4.2), that would raise the pack temperature 11C without any cooling.

Cheers, Wayne
 
Incorrect. Both of you.

Tesla tried liquid cooled cables, not pins. 60kWh Tesla has never charged at 120kW rate.

There is conversation inefficiency from AC to DC but there is also inefficiency in the pack itself.
Or you think Leaf battery heats up with magic during 30 minute DC charge cycle? :roll:
Does your car do this sound when you cool the cabin at 1.2kW AC?
https://www.youtube.com/watch?v=D18gsJgYfd4
 
arnis said:
Incorrect. Both of you.
Perhaps.

I spent ten minutes trying to the find the heating rate of charging a lithium ion battery at 1C or 2C, and didn't find any good answers. Battery university (http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries) seems to claim that charging cobalt blended lithium ion at rates of 0.5C to 1.0C is 99% efficient, but I'd prefer a primary source. I doubled the 1% inefficiency for my computation for good measure.

So I'd be interested in any references you have for the charging efficiency being only 90%, heating-wise.

Cheers, Wayne
 
That's the thing. It is not a fixed number. It depends on charge state and chemistry and
charging speed and temperature and how old the battery is (degraded Leaf vs new).

90% is a number easy to understand. It is not that bad with Leaf. I believe.
I will check DC charging station DC output and LeafSpy charge data next time.
But I'm not sure that station calculates independently.
 
arnis said:
That's the thing. It is not a fixed number. It depends on charge state and chemistry and
charging speed and temperature and how old the battery is (degraded Leaf vs new).
Sure, I agree, but for a first approximation we just need an average figure. I'm surprised I couldn't locate even an approximate answer to the question: what fraction of the DC energy put into charging a large format lithium battery ends up as heat? There's a big difference between 1% and 10%.

BTW, the Enphase AC battery claims a round trip efficiency of 96%. Of course, that's a small battery (1.2 kWh) and I don't know what charge/discharge rate that was measured at. But it does make it seem like DC charging loss of only 1% to 2% is plausible.

Cheers, Wayne
 
For now, lets just estimate whats going on with the best example we have.
Tesla. With bigger battery. It charges at speed up to 120kW.
Let's assume 98% one way efficiency. That is only 2.4kW of heat.
I know that Tesla uses 6kW resistive heater for battery heating (Tesla has excellent battery thermal management).
I don't have exact number but I've heard it takes half an hour to heat it up from cold to acceptable, guess that is 10-15
degrees (international!). Tesla pushes 6kW of heat and it takes a lot of time.

We can clearly state that at 120kW speed Tesla battery gets much more than 2.4kW of heat.
To be more exact Tesla is not able to charge at maximum speed in some scenarios because of thermal throttling.

http://insideevs.com/tesla-ups-supercharger-charging-rate-refreshed-model-s-90d-p90d-video/
charging.jpg


Do we agree that Tesla can extract heat at minimum 6kW rate?
 
arnis said:
We can clearly state that at 120kW speed Tesla battery gets much more than 2.4kW of heat.
To be more exact Tesla is not able to charge at maximum speed in some scenarios because of thermal throttling.
That's a non-sequitur. Is thermal throttling only based on pack temperature, or could it be based on the temperature of other electrical components, like the big relay that Tesla uses to switch the power input pins between the charger and the battery?

To determine the heating inefficiency of charging, we'd need the following data on a charging session:

Starting pack temperature
Ending pack temperature
Pack thermal coefficient
Pack heat lost to cooling
Energy delivered in kWh

The computation would be a lot simpler if any forced pack cooling is temporarily disabled for this data gathering. Depending on how well the pack is thermally isolated, we might also need to know the passive cooling rate when the pack is above ambient temperature. If the temperature decay rate is low enough, and the charge session is short enough, we can ignore the passive cooling.

arnis said:
Do we agree that Tesla can extract heat at minimum 6kW rate?
No, I don't know anything about how Tesla extracts heat from its packs, and you haven't presented any data on the topic.

Cheers, Wayne
 
What? :roll:

First of all:
https://www.youtube.com/watch?v=D18gsJgYfd4
This noise is Tesla running AC compressor and main fans. This is due to battery pack getting hot.
This same stuff occurs when Tesla makes a drag race but that is not because of pack. Motor/inverter are not used during SCing.

Secondly: Tesla calls "passive cooling" cooling with glycol without AC and fans. So it kinda means something else for Leaf guys.

Three: Yes, thermal throttling is MOSTLY due to pack getting hot. There were some instances due to plug getting too hot (needs service).
Contactors don't get even warm at 120kW rate.

Tesla has sophisticated thermal system. Research that:

http://c1cleantechnicacom-wpengine.netdna-ssl.com/files/2016/02/20160126_162710.jpg (passive cooling drivetrain, battery idle )
https://i.imgur.com/TOUXlWM.png (p
https://1.bp.blogspot.com/-djg9fnihcEA/VwSRUDQFbfI/AAAAAAAAABY/Y-3AV0_I5owyxLxYedZjXPFloDkEgGlkA/s1600/factory_thermal_censored.jpg (battery passive heating, using drivetrain heat, cabin cooling)
 
We do thermal throttling with JdeMO for the 2012-2014 Toyota RAV4 EV and Tesla Roadster:

125 amps - max now, may go up to 200 amps in the future.

90 amps max - 45C / 113F degrees battery temp
60 amps max - 47C / 117F degrees battery temp
30 amps max - 49C / 121F degrees battery temp
OFF -------------- 51C / 125F degrees battery temp
 
Today I did a 10min DC charge with healthy 24kWh Leaf battery at exactly 1.4C - constantly - 32kW speed.
I got a result: 97% efficiency. This was in the low SOC part. And only 1/4 of all capacity was charged.
Unfortunatly I can not be sure that number on DC station and LeafSpy are very accurate.

For now (without additional information) I suppose 3% inefficiency is possible at "not that fast rate" and "low SOC".
I suppose Tesla has no worse than 95% efficiency at 120kW rate.
Therefore appr. max 120x0,05=6kW of heat generation in the pack.
This looks plausible. At the same time big question mark - why Tesla can not handle keeping the pack at constant temperature
at very warm weather scenario.
 
TonyWilliams said:
We do thermal throttling with JdeMO for the 2012-2014 Toyota RAV4 EV and Tesla Roadster:

125 amps - max now, may go up to 200 amps in the future.

90 amps max - 45C / 113F degrees battery temp
60 amps max - 47C / 117F degrees battery temp
30 amps max - 49C / 121F degrees battery temp
OFF -------------- 51C / 125F degrees battery temp

I'll buy an upgrade for my JdeMO. The current version you installed on my car works exceptionally well and of course, faster is always welcomed. Thanks for making my Rav4 great again!

For the 350 KWH charger, it is a welcome good sign of progress. I'm impressed with the Fast Charger rollout that EVGO is doing in California. I would have thought ChargePoint would be more aggressive, I hear they're working on it. As soon a Quick Charge station goes online near me, I pay to use it to support the rollout and expansion of the infrastructure, proving the use case. Bring on the EV, Lighting Fast Charger, connected cities.
 
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