6 ms·

Why Tesla's EV charging system won the race to become America's standard

21 points by mr-marbo 2y ago

IshKebab 2y ago
Shame Europe is going to be stuck with the inferior CCS2 forever.
- deleted 2y ago
  [deleted]
- slaw 2y ago
  NACS doesn't support 3-phase electric power so it is not an option in Europe.
  - umeshunni 2y ago
    Is there a technical reason that's not possible in a future update to NACS?
    - IshKebab 2y ago
      It doesn't have enough wires. For power NACS has 2 wires for single phase AC or DC and a small ground wire. CCS2 has 7 wires. 5 for 3 phase power (3 phases + ground + neutral) and 2 more for DC. It a pretty mad design. If you think about it CCS2 requires every single car to lug around a 3 phase battery AC-DC converter instead of just putting it with the chargers. Doesn't make sense.
      - labcomputer 2y ago
        > 3 phase battery AC-DC converter instead of just putting it with the chargers 3-phase -> DC is easier than single phase. One of the benefits of 3-phase is that power delivered is constant, so you don't need very big capacitors. That's part of the reason nobody makes a DC fast charger bigger than about 20kW.
        IshKebab 2y ago
        Yes but is 3 phase 22kW easier than 1 phase 7kW? I doubt it.
      - anonfordays 2y ago
        >It doesn't have enough wires. For power NACS has 2 wires for single phase AC or DC and a small ground wire Two wires is enough for 208V phase-to-phase from a three phase power source [0]. NACS supports three phase power sources in this configuration. [0] https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Flookaside.fbsbx.com%2Flookaside%2Fcrawler%2Fmedia%2F%3Fmedia_id%3D760674931244317&f=1&nofb=1&ipt=12ff2fb3ed23c873411cd19b1df0c6ed2b52bb8f17fa2459a565a7a10de5c173&ipo=images https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...
  - IshKebab 2y ago
    You can run single phase devices off 3 phase supply. Most houses do not have 3 phase supply in Europe. It varies by country, but for example almost no houses have 3 phase supply in the UK. I couldn't find any actual data for other countries but based on Reddit questions etc. it's common in Sweden and Germany, rare in France and Spain. So support for 3 phase definitely isn't an issue for residential use, where you don't really care about the charging speed. And it isn't an issue for public charging because you'll want to use fast DC charging there.
    - theluketaylor 2y ago
      3 phase is a huge deal, especially for commercial fleets. For public charging DC fast chargers are incredibly expensive, whereas a 3 phase AC charger is pretty cheap and effectively the same price as single phase charger. Delivering more power for the same install cost is valuable since it opens more charging use cases for low cost charging. I think north america is going to regret not having 1st class support for 3 phase charging baked into all electrified vehicles in the long term.
      - IshKebab 2y ago
        > For public charging DC fast chargers are incredibly expensive Maybe so but 3 phase AC is already the minority, and we've barely started the transition to electric cars. Look at https://www.zap-map.com/live https://www.zap-map.com/live Orange is 3 phase AC. It's about as popular as single phase, and way less popular than DC. They just opened a brand new transport hub near me with 100 charging points. All single phase. I just don't think it's a big deal. I don't think people really care about the difference between 7 kW (takes hours to charge) and 22 kW (takes hours to charge). Maybe people don't care about the hilarious clumsiness of the plug either; I don't know.
        lrasinen 2y ago
        Over in Finland the usual home charger options are 3.6 kW and 11 kW, and that makes a difference (24 hrs vs overnight). Also three-phase AC is ubiquitous here, you need it to run your sauna stove :D
  - anonfordays 2y ago
    You are incorrect. Two wires is enough for 208V phase-to-phase from a three phase power source [0]. NACS supports three phase power sources in this configuration. [0] https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Flookaside.fbsbx.com%2Flookaside%2Fcrawler%2Fmedia%2F%3Fmedia_id%3D760674931244317&f=1&nofb=1&ipt=12ff2fb3ed23c873411cd19b1df0c6ed2b52bb8f17fa2459a565a7a10de5c173&ipo=images https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...
- pornel 2y ago
  CCS2 is clunkier than NACS, but not too bad. At least it doesn't have the big external latch that CCS1 has.
kimixa 2y ago
This reads more like a puff piece about Tesla's charging system than a real discussion on /why/ anything matters. And the prose is positive about everything. I'd love to know what information is "missing" from the J1772 communication protocol, the trade offs on a digital vs analogue "protocol"? Does it require more control circuitry on each side? Are there safety issues with such high power being controlled by a relatively complex microcontroller and protocol? Is the claimed difference even relevant? J1772 has since 2012 allows digital information to be passed using a AC power-line communication standard. J1772 claims to support 240v, so why are they only using numbers showing the "advantage" of the (likely only available in non-residential supplies) 277v compared to 208v? And why aren't the comparing agains the CCS2 standard? Surely that's the most obvious competitor? The article being so unfailingly positive yet incomplete triggers my "Advert" detector.
- cogman10 2y ago
  Pretty much nothing was missing from the J1772 protocol, that's why NACS by and large speaks it and CCS1/2. That's pretty much the answer to all your questions, it's a different plug standard using other SAE standards for communication. As to why it won out in the US, pretty much solely due to the fact that Tesla is basically the only national charge network that gives a damn about their charge network. It's a crap shoot for basically every other charge location and the actual coverage is pitiful compared to the Tesla network.
- labcomputer 2y ago
  > I'd love to know what information is "missing" from the J1772 communication protocol, the trade offs on a digital vs analogue "protocol" I think the author is confusing the DC and AC aspects of NACS. AFAIK, NACS uses the same J1772 analog protocol for AC charging. I don't think it really matters that much, but if you were designing things from scratch today, it might be nice to have things like: * Plug-and-charge at commercial AC chargers. Nobody has this today. * Tell the car whether off/mid/peak energy rates apply (at home AC chargers). You could program your car to charge only at off&mid rates, unless the battery is empty, then let the EVSE figure out what rates apply. * Send state-of-charge from car to charger, to enable smarter load balancing: Several companies make EVSEs that can supply full current when one car is present, but command the first to throttle back to half current when a second car is plugged in. You might want to adjust that split to, say, 75/25 if the new car is near empty. > J1772 has since 2012 allows digital information to be passed using a AC power-line communication standard. Ehh... not really. The J1772 analog protocol can tell the car "hey, I'm actually a CCS station, so let's talk CSS digital protocol". But J1772 itself doesn't define any kind of digital protocol. > the "advantage" of 277v compared to 208v? The advantage is that if you happen to have "480V 3-phase" service available (which is common in commercial and industrial settings), you can directly attach NACS between one phase and ground (which gives you 277V). With J1772 you need a transformer to step down to "120V 3-phase" (which gives you 208V between two phases). You also get about 30% more power for the same conductor weight, which makes the copper wiring cheaper. The two common distribution voltages in North America are 277/480 (phase-ground and phase-phase) and 120/208 (phase-ground and phase-phase). We also have 240, which is "split phase" (two conductors 180 degrees apart). > And why aren't the comparing agains the CCS2 standard? Surely that's the most obvious competitor? Well, CCS2 is the DC charging "add-on" to J1772. So IMHO it doesn't really make sense to talk about it in the context of AC charging, unless you're trying to "well akshually... gotcha" someone with an obscure technical point. If you do want compare NACS and CCS2, the biggest one is simply ergonomics: CCS2 is like mini-USB (not even micro), while NACS is lightning/USB-C. CCS2 is heavy, bulky, and sometimes fails to make a good connection. You need to get the alignment just right to insert and apply a lot of force to get the thing locked in. To remove, you again need to throw your back into it. NACS, by contrast, just pops in and out with your finger tips. NACS ports are curved to guide in a slightly misaligned plug. If you haven't tried it yet, you really owe it to yourself to rent a Model 3 for the weekend and supercharge a couple times. The ergonomics are just vastly superior.
curtis3389 2y ago
I doubt it will be _the_ standard, though. I think we'll need to flip the setup so that a cord is in the car with people stealing them for the copper.
evereverever 2y ago
Well they have promised to open it up to more cars but have not yet, so I guess, in theory, they have, but not in practice.

21 points by mr-marbo 2y ago

IshKebab 2y ago

Shame Europe is going to be stuck with the inferior CCS2 forever.

deleted 2y ago
[deleted]
slaw 2y ago
NACS doesn't support 3-phase electric power so it is not an option in Europe.
- umeshunni 2y ago
  Is there a technical reason that's not possible in a future update to NACS?
  - IshKebab 2y ago
    It doesn't have enough wires. For power NACS has 2 wires for single phase AC or DC and a small ground wire. CCS2 has 7 wires. 5 for 3 phase power (3 phases + ground + neutral) and 2 more for DC. It a pretty mad design. If you think about it CCS2 requires every single car to lug around a 3 phase battery AC-DC converter instead of just putting it with the chargers. Doesn't make sense.
    - labcomputer 2y ago
      > 3 phase battery AC-DC converter instead of just putting it with the chargers 3-phase -> DC is easier than single phase. One of the benefits of 3-phase is that power delivered is constant, so you don't need very big capacitors. That's part of the reason nobody makes a DC fast charger bigger than about 20kW.
      - IshKebab 2y ago
        Yes but is 3 phase 22kW easier than 1 phase 7kW? I doubt it.
    - anonfordays 2y ago
      >It doesn't have enough wires. For power NACS has 2 wires for single phase AC or DC and a small ground wire Two wires is enough for 208V phase-to-phase from a three phase power source [0]. NACS supports three phase power sources in this configuration. [0] https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Flookaside.fbsbx.com%2Flookaside%2Fcrawler%2Fmedia%2F%3Fmedia_id%3D760674931244317&f=1&nofb=1&ipt=12ff2fb3ed23c873411cd19b1df0c6ed2b52bb8f17fa2459a565a7a10de5c173&ipo=images https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...
- IshKebab 2y ago
  You can run single phase devices off 3 phase supply. Most houses do not have 3 phase supply in Europe. It varies by country, but for example almost no houses have 3 phase supply in the UK. I couldn't find any actual data for other countries but based on Reddit questions etc. it's common in Sweden and Germany, rare in France and Spain. So support for 3 phase definitely isn't an issue for residential use, where you don't really care about the charging speed. And it isn't an issue for public charging because you'll want to use fast DC charging there.
  - theluketaylor 2y ago
    3 phase is a huge deal, especially for commercial fleets. For public charging DC fast chargers are incredibly expensive, whereas a 3 phase AC charger is pretty cheap and effectively the same price as single phase charger. Delivering more power for the same install cost is valuable since it opens more charging use cases for low cost charging. I think north america is going to regret not having 1st class support for 3 phase charging baked into all electrified vehicles in the long term.
    - IshKebab 2y ago
      > For public charging DC fast chargers are incredibly expensive Maybe so but 3 phase AC is already the minority, and we've barely started the transition to electric cars. Look at https://www.zap-map.com/live https://www.zap-map.com/live Orange is 3 phase AC. It's about as popular as single phase, and way less popular than DC. They just opened a brand new transport hub near me with 100 charging points. All single phase. I just don't think it's a big deal. I don't think people really care about the difference between 7 kW (takes hours to charge) and 22 kW (takes hours to charge). Maybe people don't care about the hilarious clumsiness of the plug either; I don't know.
      - lrasinen 2y ago
        Over in Finland the usual home charger options are 3.6 kW and 11 kW, and that makes a difference (24 hrs vs overnight). Also three-phase AC is ubiquitous here, you need it to run your sauna stove :D
- anonfordays 2y ago
  You are incorrect. Two wires is enough for 208V phase-to-phase from a three phase power source [0]. NACS supports three phase power sources in this configuration. [0] https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Flookaside.fbsbx.com%2Flookaside%2Fcrawler%2Fmedia%2F%3Fmedia_id%3D760674931244317&f=1&nofb=1&ipt=12ff2fb3ed23c873411cd19b1df0c6ed2b52bb8f17fa2459a565a7a10de5c173&ipo=images https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2F...
pornel 2y ago
CCS2 is clunkier than NACS, but not too bad. At least it doesn't have the big external latch that CCS1 has.

kimixa 2y ago

This reads more like a puff piece about Tesla's charging system than a real discussion on /why/ anything matters. And the prose is positive about everything. I'd love to know what information is "missing" from the J1772 communication protocol, the trade offs on a digital vs analogue "protocol"? Does it require more control circuitry on each side? Are there safety issues with such high power being controlled by a relatively complex microcontroller and protocol? Is the claimed difference even relevant? J1772 has since 2012 allows digital information to be passed using a AC power-line communication standard. J1772 claims to support 240v, so why are they only using numbers showing the "advantage" of the (likely only available in non-residential supplies) 277v compared to 208v? And why aren't the comparing agains the CCS2 standard? Surely that's the most obvious competitor? The article being so unfailingly positive yet incomplete triggers my "Advert" detector.

cogman10 2y ago
Pretty much nothing was missing from the J1772 protocol, that's why NACS by and large speaks it and CCS1/2. That's pretty much the answer to all your questions, it's a different plug standard using other SAE standards for communication. As to why it won out in the US, pretty much solely due to the fact that Tesla is basically the only national charge network that gives a damn about their charge network. It's a crap shoot for basically every other charge location and the actual coverage is pitiful compared to the Tesla network.
labcomputer 2y ago
> I'd love to know what information is "missing" from the J1772 communication protocol, the trade offs on a digital vs analogue "protocol" I think the author is confusing the DC and AC aspects of NACS. AFAIK, NACS uses the same J1772 analog protocol for AC charging. I don't think it really matters that much, but if you were designing things from scratch today, it might be nice to have things like: * Plug-and-charge at commercial AC chargers. Nobody has this today. * Tell the car whether off/mid/peak energy rates apply (at home AC chargers). You could program your car to charge only at off&mid rates, unless the battery is empty, then let the EVSE figure out what rates apply. * Send state-of-charge from car to charger, to enable smarter load balancing: Several companies make EVSEs that can supply full current when one car is present, but command the first to throttle back to half current when a second car is plugged in. You might want to adjust that split to, say, 75/25 if the new car is near empty. > J1772 has since 2012 allows digital information to be passed using a AC power-line communication standard. Ehh... not really. The J1772 analog protocol can tell the car "hey, I'm actually a CCS station, so let's talk CSS digital protocol". But J1772 itself doesn't define any kind of digital protocol. > the "advantage" of 277v compared to 208v? The advantage is that if you happen to have "480V 3-phase" service available (which is common in commercial and industrial settings), you can directly attach NACS between one phase and ground (which gives you 277V). With J1772 you need a transformer to step down to "120V 3-phase" (which gives you 208V between two phases). You also get about 30% more power for the same conductor weight, which makes the copper wiring cheaper. The two common distribution voltages in North America are 277/480 (phase-ground and phase-phase) and 120/208 (phase-ground and phase-phase). We also have 240, which is "split phase" (two conductors 180 degrees apart). > And why aren't the comparing agains the CCS2 standard? Surely that's the most obvious competitor? Well, CCS2 is the DC charging "add-on" to J1772. So IMHO it doesn't really make sense to talk about it in the context of AC charging, unless you're trying to "well akshually... gotcha" someone with an obscure technical point. If you do want compare NACS and CCS2, the biggest one is simply ergonomics: CCS2 is like mini-USB (not even micro), while NACS is lightning/USB-C. CCS2 is heavy, bulky, and sometimes fails to make a good connection. You need to get the alignment just right to insert and apply a lot of force to get the thing locked in. To remove, you again need to throw your back into it. NACS, by contrast, just pops in and out with your finger tips. NACS ports are curved to guide in a slightly misaligned plug. If you haven't tried it yet, you really owe it to yourself to rent a Model 3 for the weekend and supercharge a couple times. The ergonomics are just vastly superior.

curtis3389 2y ago

I doubt it will be _the_ standard, though. I think we'll need to flip the setup so that a cord is in the car with people stealing them for the copper.

evereverever 2y ago

Well they have promised to open it up to more cars but have not yet, so I guess, in theory, they have, but not in practice.