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Electric Vehicles are a key part of our tomorrow and how we get there. If we can get all the fossil fuel vehicles off our roads, out of our seas and out of our skies, we'll have a much better environment. This community is where we discuss the various different vehicles and news stories regarding electric transportation.
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Kempower unveiled its new charger [...] that can dispense 1.2 mW
At 1.2 mW, my electric car would need roughly 8.5 millenia to charge. At its average consumption, every kilometer driven would require 35 years of recharging. Like, I don't want to sound too picky, but I guess I'd rather walk tbh.
Almost no one can keep kW and kWh straight, why would you think they could understand MW?
KWh is super dumb, though, like they were trying for maximum confusion when they invented it.
Is it?
Would you measure distance in "1,000 meter per second minutes?"
I don't understand.
Well, precisely!
A watt is a unit of power. It's an energy rate, it involves time. It's 1 joule per second (J/s).
A watt-hour is the amount of energy delivered at a rate of 1 watt over the course of one hour. (J/s x h). And here we get into the trouble already. (The kilowatt-hour is just 1,000 watt-hours, that's not the source of the trouble.)
Now we have a unit of energy (the watt-hour) that includes the names of a unit of power (watt, which is a rate) and a unit of time (hour) but the watt-hour (and the kilowatt-hour) measures neither of those things. The watt-hour is defined as ((energy / time unit) x different time unit). It's insane. Even though the time units should cancel out, we keep the ghost of both time units in the name, to no purpose. It works out to just joules; 1 Wh is 3,600 joules. 1 kWh is 3,600,000 joules.
It is exactly analogous to measuring distance in "meter-per-second-minutes," when you've got meters right there.
We should have stuck with MJ and MJ/s. No need to get W or h involved.
kW and kWh helps understanding charging speed/capacity better than MJ and MJ/s.
Btw. 1 MJ/s = 1 MW, but you surely know that.
This is not what we need. We need more chargers in convenient locations. There are multiple popular highway rest stops in my region that do not have DCFC. In an ideal world, apps like ABRP would be unnecessary for road trips. If I make a bathroom stop, I should also be able to charge. Don't stop to charge, charge when you stop.
Fully. Last road trip we took the PHEV and just used gas. I looked for the EV chargers on the way because taking the EV was an option (the EV is smaller, so would be crowded with the whole family), and most places did have them. Sure the EV charging station had them, but they were only rarely on the exits, it was always drive a few minutes off the freeway instead of right at the end of the ramp. Many of them didn't have restrooms or snacks to buy (the latter is how gas stations make money). There were a few exceptions, but in general locations exist for long trips but they are still not convenient.
I don't mind driving a couple minutes to get a good charger, but there should be at least 100 kW chargers (preferably higher) at all rest areas that are already electrified. When my family stops for a quick pee and leg stretch, it easily takes 15 minutes. It would be super cool to stop at the most convenient spot where I don't even have to leave the highway fully and get 75+ extra miles of charge.
I say we need both.
People who go long distances need to stop to charge.
1 Megawatt though? I think 400 kW is plenty.
We need both.
In ideal conditions, a 300 kW charger can deliver 50 kWh in 10 minutes. That's mostly fine, but on a road trip still involves 10 minutes of charging every 2 hours, much more frequently than the typical restroom break or snack break.
And if people are going to be leaving their cars to do other stuff while charging, there need to be a lot of stalls so that there are open spots at popular rest stops. Delivering high power to each stall is helpful to speed them to idle/trickle, so that the overall circuit for the whole set of multiple chargers can efficiently direct the power to where it's needed most.
The current status quo is about 20 minutes every 3 hours (in a model 3), which is a perfect travel pace IMO. People consistently underestimate how long they spend stopped on road trips. The EV adds about 4 minutes per hour for each hour past 3. It's really not a big deal.
What is a bigger deal is when charger locations are poorly located, requiring inefficient stopping schedules.
a perfect travel pace IMO
You're obviously free to do road trips the way you want to do them, and 20 minutes every 3 hours is the kind of thing I can do with my kids, but on trips I'm doing without the kids I'd prefer the option of stopping for less than 10 minutes every 3 hours. I have a 500 mile trip planned this summer and I'm basically gonna throw in an overnight hotel stay in part to make it easier to top off at a charger while we sleep, but if I still had a gasoline vehicle I probably would just be driving straight through by leaving early in the morning, rather than doing an evening drive starting the night before.
And I'm with you on the charger locations being a bigger inconvenience. It takes a lot more planning/flexibility (ABRP and a few backup plans in case certain chargers are occupied or out of service or slower than advertised when I get there). But still, I'd like to see improvement in the driver experience for all of it.
Most cars and drivers don't need this. And most chargers won't be upgraded anyway.
I beg to differ.
Charging time is still a strong deterrent for a lot of people considering EV instead of ICE vehicles.
I'd be happy to have such capabilities available, because I often charge my EV away from home and it'd be nice to have it done even faster, although I'm quite ok with 10-80% (equalling close to 300 km/190 miles) in around 20 minutes.
Most people don't drive 500 miles regularly. Most people can wait 15 minutes to charge and then go on their way. Most existing chargers are good enough and won't be upgraded any time soon.
Who cares about what they do regularly. What maters is what they do EVEN ONCE! Most people do take 1000 mile road trips - about once a year. They expect their cars to do this. Sure you can rent a car - but that is very expensive - it is typically cheaper to just buy a single car that can do everything. The cost of a rental car (remember poor transit in the US when you get there) also drives a lot of people away from flying or amtrak.
And the current charging infrastructure can handle this quite well.
Not exactly. It can but chargers are rarely in convenient locations. You shouldn't have to use an app to find a charger there should be big signs. And things to do at the charger.
Sure. But this topic is about Faster Charging and Megawatt chargers. Most people don't need this.
I'm not convinced. Both are needed. Most of the time most people don't need megawatt charging but I think most people really want it once a year. And as also brought out if semis are to go electric they need this so if cars can use it too that is good.
That is true, but at least for now, there are many people who would wish for 5 minute charging. I guess people here love to lecture that you don't need it, while the Chinese like byd and catl just build what the people want.
Are they trying to make viable EV pit stops for racing?
I guess this would make ridiculously sized batteries for semis viable. Though I'd rather pivot back to freight trains than put that much weight on our roads.
Semis are responsible for most of the road repair budget in the US. There's a cheaper way. (If the government didn't pick up the tab for all this semi road damage.)
Semis are responsible for most of the road repair budget in the US
No, I think you're jumping to an invalid conclusion here.
Yes, heavy vehicles cause much more wear and tear on roads than light vehicles do. But a lot of road damage is caused by stuff other than vehicles driving normally on top.
Most road surface repair is necessitated by weather: freezing and thawing creating cracks, physical scraping from snow plows. Plus there are issues caused by soil erosion, tree roots pushing on stuff, other wear and tear caused by stuff falling or blowing on the road.
You can see it in places that have dedicated bike lanes, narrow residential streets where heavy vehicles simply can't drive, etc. When the pavement gets old, potholes and other cracks still form, even with no heavy vehicle ever driving over it.
Those chargers are useful for the next generation consumer EVs.
https://www.byd.com/mea/news-list/byd-unveils-super-e-platform-with-megawatt-flash-charging
Alas, the BYD ones will be hard to get by in the USA. Unless some American EV manufacturers can keep up with the Chinese EV manufacturers, ICE cars will be "recharged" faster than EVs - mission accomplished, I guess.