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[deleted] t1_is34co6 wrote

Reply to comment by my_lewd_alt in South Korean researchers say they have developed an anode-free lithium-ion battery that is 40% more energy dense than existing batteries and will enable EVs to travel 630km (390 miles) on a single charge. by lughnasadh

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CloneEngineer t1_is3wx8s wrote

Kw/h is a meaningless unit. Kw has units of kilojoules/sec, it's already a rate. The unit kw-hr - or kj-hr/sec is a capacity unit cause the time "cancels". Kinda. Kw-hr units are strange in a lot of ways.

I don't think kw / kw-hr are intuitive units for most people.

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Billysmalltits t1_isxgqt8 wrote

So you're saying 1kW/hr, which obviously means a power output of 1kW for a time of 1 hour is less intuitive than saying 3.6 megajoules?

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CloneEngineer t1_isxhvzj wrote

You wrote the units wrong also. You want kw*hr, not kw/hr. Maybe not so obvious?

I'm saying kw is already a rate. It's units are J,/s. Kw/hr would have units of J/s-hr. That makes no sense. Another way to say you supply 3.6 MJ in an hour would be to say 1Kw-hr/hr. And hrs cancel to 1Kw.

Most people want kw*hr, not kw/hr. Kw/hr would be the rate of change of charging speed. Ie, I started charging at 1kw, an hour later I'm charging at 11kw, charging rate increased at 10kw/hr.

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OmnipotentCthulu t1_is4dhg1 wrote

The only thing i would think you meant to say is the speed is limited to 10kw and added an h on accident. Now that you are getting on him saying we should all know you meant 10kw/h im curious wtf that unit is supposed to mean.

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HighClassProletariat t1_is3z28k wrote

Most humans would not realize that because they don't know the difference between kW and kWh, and that's why this person corrected you.

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[deleted] t1_is4nfee wrote

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User172381021 t1_is5298a wrote

It's not a shit unit. It just isn't a SI unit. kWh are cool so you can relate it to an hour. If you charge something with 500W you know it has 0.5kWh after an hour. Just like km/h is used instead of m/s

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[deleted] t1_is6qano wrote

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User172381021 t1_is72xxq wrote

WTH is your strawman here. Please try to understand what i wrote instead of arguing against something i did not say. I did not say anything about vehicles. I agree that in the case of cars and their batteries kWh related to their distance they might be able to travel, kWh does not make sense. But charging money by the kWh is common. So if you charge your 1kWh car battery (or whatever) you know a 1kW supply needs 1hour to fill the battery. And I know how to convert units.

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