4 ms·

There seems to be no indication of the power demands of charging at this rate. I don't have the figures to do the maths but I suspect a normal household supply

There seems to be no indication of the power demands of charging at this rate. I don't have the figures to do the maths but I suspect a normal household supply could not support this. Anyone?

jgilias 3y ago
But you don’t need to have a 10 minute charger at home. At home overnight charging is completely fine.
- ljlolel 3y ago
  Anyone in city apartments (millions/billions of people, half the world) can't do that.
  - jgilias 3y ago
    Yes, and for these people the 10 minute charger will be needed, the parent comment spoke specifically about installing this at home.
    - ljlolel 3y ago
      Ah thanks
donny2018 3y ago
I'm not an engineer but I attempted to do some napkin math in my comment in a previous topic about this CATL battery. I'll copy/paste: Assuming 400km worth of charge needs maybe 60 kw/h of energy, to deliver that amount of energy in 10 minutes would require at least 360kw charger. Charging just a few cars simultaneously will require megawatts of power. I wonder what are the implications in terms of city infrastructure or investment costs to building charging stations for that.
- davedx 3y ago
  V3 Superchargers are 250 kW per car with 1MW power cabinets. The issue at the moment is that grids in a lot of places in the world can't keep up with the connection requests, and this is indeed mainly due to not being able to upgrade transmission capacity fast enough.
  - ZeroGravitas 3y ago
    One of the boring ways to upgrade the grid is to raise the transmission limits set to prevent overheating in the summer when it's cold in the winter. Reminds me of "the duck curve" where the worry was that gas plants couldn't ramp output fast enough. There were many exciting high tech solutions but one solution was just to ask the gas plants if they could ramp faster. Turns out they could, they'd just not needed to before. Seems to be a recurring pattern: you can hyperventilate about how something is hard or impossible or you can ask some engineers if they can improve things. If you get really desperate you can pay people for coming up with solutions and create a market. Of course that all assumes you actually want to solve the problem. edit: recent third example. Grid connection queues in England had zombie projects in them because you got fined if you left the queue. They had an amnesty and a bunch off them dropped out moving up dates for real projects.
    - davedx 3y ago
      Yup, this is because most things that are engineered have tolerances in them. But pushing the envelope will only get you so far, at some point you're going to run up against hard physical limits (in this case with grid transmission capacity). The National Grid connection queue is still a huge bottleneck for renewable and battery developers. The amnesty helped but at the end of the day, the overhead lines, substations and transformers need to be upgraded. At least in the UK there's quite some visibility into the queue and required and ongoing works. Here in Europe it's like a black box.
rkangel 3y ago
They say 4C and a Model 3 battery pack is apparently 60kWh so that would be 240kW. That's ignoring inefficiency though, so we're talking significant fractions of a megawatt to charge one car.
- pedrocr 3y ago
  250 to 350kW chargers are already in common use. And batteries that charge this fast too. What's news here is that they've done it on an LFP battery which is the cheaper kind of lithium chemistry.
  - rkangel 3y ago
    What other batteries are in mass manufacture that charge this fast?
    - pedrocr 3y ago
      Lipo chemistries used in hobby applications are often rated at 5C charging for example versus 4C here. To get a good comparison in a car we need a manufacturer to actually do the development work and release a car that can be tested in real world conditions. There are the temperature limitations the press release already mentions and also limits to avoid range loss from fast charging over the life of the car.
ifdefdebug 3y ago
Probably not, but does it matter? When parking at home, your car usually is a few hours at rest anyway. This is interesting for charging at a service station.
londons_explore 3y ago
It could not. However, a household supply could supply substantially more with smarter software. Specifically, currently we rate power supplies with a decent safety margin for worst-case conditions. However, your '100 amp' power supply can probably supply 200 amps on a freezing cold day (which helps keep cables cool). It can probably supply more than rated if your neighbours aren't using much (since your and your neighbours power connections may share cables). If you or your neighbours have rooftop solar, thats power going the other direction, which cancels out some power use - allowing you to charge even faster. If software could take these factors into account, we could get a lot more power to where it needs to be. Currently rules don't allow such things though.

There seems to be no indication of the power demands of charging at this rate. I don't have the figures to do the maths but I suspect a normal household supply could not support this. Anyone?

jgilias 3y ago

But you don’t need to have a 10 minute charger at home. At home overnight charging is completely fine.

ljlolel 3y ago
Anyone in city apartments (millions/billions of people, half the world) can't do that.
- jgilias 3y ago
  Yes, and for these people the 10 minute charger will be needed, the parent comment spoke specifically about installing this at home.
  - ljlolel 3y ago
    Ah thanks

donny2018 3y ago

I'm not an engineer but I attempted to do some napkin math in my comment in a previous topic about this CATL battery. I'll copy/paste: Assuming 400km worth of charge needs maybe 60 kw/h of energy, to deliver that amount of energy in 10 minutes would require at least 360kw charger. Charging just a few cars simultaneously will require megawatts of power. I wonder what are the implications in terms of city infrastructure or investment costs to building charging stations for that.

davedx 3y ago
V3 Superchargers are 250 kW per car with 1MW power cabinets. The issue at the moment is that grids in a lot of places in the world can't keep up with the connection requests, and this is indeed mainly due to not being able to upgrade transmission capacity fast enough.
- ZeroGravitas 3y ago
  One of the boring ways to upgrade the grid is to raise the transmission limits set to prevent overheating in the summer when it's cold in the winter. Reminds me of "the duck curve" where the worry was that gas plants couldn't ramp output fast enough. There were many exciting high tech solutions but one solution was just to ask the gas plants if they could ramp faster. Turns out they could, they'd just not needed to before. Seems to be a recurring pattern: you can hyperventilate about how something is hard or impossible or you can ask some engineers if they can improve things. If you get really desperate you can pay people for coming up with solutions and create a market. Of course that all assumes you actually want to solve the problem. edit: recent third example. Grid connection queues in England had zombie projects in them because you got fined if you left the queue. They had an amnesty and a bunch off them dropped out moving up dates for real projects.
  - davedx 3y ago
    Yup, this is because most things that are engineered have tolerances in them. But pushing the envelope will only get you so far, at some point you're going to run up against hard physical limits (in this case with grid transmission capacity). The National Grid connection queue is still a huge bottleneck for renewable and battery developers. The amnesty helped but at the end of the day, the overhead lines, substations and transformers need to be upgraded. At least in the UK there's quite some visibility into the queue and required and ongoing works. Here in Europe it's like a black box.

rkangel 3y ago

They say 4C and a Model 3 battery pack is apparently 60kWh so that would be 240kW. That's ignoring inefficiency though, so we're talking significant fractions of a megawatt to charge one car.

pedrocr 3y ago
250 to 350kW chargers are already in common use. And batteries that charge this fast too. What's news here is that they've done it on an LFP battery which is the cheaper kind of lithium chemistry.
- rkangel 3y ago
  What other batteries are in mass manufacture that charge this fast?
  - pedrocr 3y ago
    Lipo chemistries used in hobby applications are often rated at 5C charging for example versus 4C here. To get a good comparison in a car we need a manufacturer to actually do the development work and release a car that can be tested in real world conditions. There are the temperature limitations the press release already mentions and also limits to avoid range loss from fast charging over the life of the car.

ifdefdebug 3y ago

Probably not, but does it matter? When parking at home, your car usually is a few hours at rest anyway. This is interesting for charging at a service station.

londons_explore 3y ago

It could not. However, a household supply could supply substantially more with smarter software. Specifically, currently we rate power supplies with a decent safety margin for worst-case conditions. However, your '100 amp' power supply can probably supply 200 amps on a freezing cold day (which helps keep cables cool). It can probably supply more than rated if your neighbours aren't using much (since your and your neighbours power connections may share cables). If you or your neighbours have rooftop solar, thats power going the other direction, which cancels out some power use - allowing you to charge even faster. If software could take these factors into account, we could get a lot more power to where it needs to be. Currently rules don't allow such things though.