There is no such thing as a Level 3 EV charger

Hello, I'm Professor John Kelly and this is the  WeberAuto YouTube channel. As a member of several   Facebook groups for various electric vehicles and  plug-in hybrid electric vehicles I often see the   term level 3 charger used when someone is really  talking about DC fast charging well I'm here to   tell you that there is no such thing as a level  3 charger now there are four different charging   levels available under the Society of Automotive  Engineers surface vehicle standard J 1772 but   it wasn't always that way the J 1772 standard  document started back in 1996 and it has been   revised seven times the latest version is the 2017  version and only in the very first two versions of   that document did it list a level three charging  standard as a proposed method of charging but it   was never implemented and has never been used  as a matter of fact, in the 1996 version, it was   referring to DC charging in the 2001 version it  was referring to AC charging the J 1772 standard   is only for conductive charge couplings where you  take a charge cord and physically plug it into   your charging port on the vehicle there is also  a J 1773 standard that is an older one for the   inductive charge couplings in this video I will  show you the for real charging system power levels   and types as outlined in the latest version of  the J 1772 standard from the Society of Automotive   Engineers okay to understand the four different  charging methods and levels you really need to   understand some basic terminology and electrical  principles the first thing to understand is that   all electric vehicles and plug-in hybrid electric  vehicles use two different direct current DC   batteries the first is a low-voltage 12-volt  battery just like any other car has the second   is a high-voltage 300 to 800 volt battery the high  voltage battery supplies power to the inverter   which drives the electric motors it also supplies  power to the air conditioning compressor and to   what is known as a DC to DC converter which is  used to charge the low-voltage 12-volt battery the   12-volt battery supplies power to everything else  on the vehicle like lights window radio's locks   etc now DC batteries like both of these batteries  we just talked about need to be charged with DC   power as I just mentioned your 12-volt DC battery  is charged with power from the high voltage DC   battery your high voltage DC battery is charged  by one of two methods when you plug your car   into a charger, chances are that charger is fed AC  power alternating current from the wall and most   Chargers supply AC power to the vehicle now as I  just said the batteries need to be charged with DC   power but the Chargers are supplying AC power so  somewhere on the vehicle there is something called   an on-board charging module and I have one right  here this is from a 2016 Chevrolet Volt that and   this is a small one the more power they can handle  the larger they are on this side of the onboard   charging module is that an electrical connector  that receives AC power directly from your plug   in charge port so when you plug your vehicle  in you're supplying power to this connector   and then this module bumps the voltage up to a  high enough voltage to charge your DC battery   and converts that AC power into DC power and that  DC power is available on this electrical connector   so all plug-in hybrid and electric vehicles have  an onboard charging module as I mentioned this   one's pretty small and this one is only rated at  a maximum of 3.6 kilo Watts so as you can see in   these photos here under the back seat of our Tesla  Model S is a very large onboard charging module   you can see the onboard charging module under the  rear hatch area of our 2018 Chevrolet Volt and you   can see under the hood here of our 2017 Chevrolet  Volt Evi the onboard charging module each charging   module is rated for a certain maximum amount of  power that it can handle so the onboard charging   module in our Chevrolet Volt right here is rated  to handle 3.6 kilo watts or 3,600 watts and that   comes from a maximum of a 240 volt source and  a 15 amp current ratings so if you multiply 240   volts times 15 amps you get 3,600 or 3.6 kilo  which means thousand watts now the on-board   charging module of our 2017 Chevrolet Bolt EV  back there is rated for almost double what the   Volt could handle and that was at seven point six  eight kilo watts or seven thousand six hundred and   eighty watts and that comes from a maximum input  voltage of 240 volts times a maximum current of 32   amps which equals seven thousand six hundred and  80 watts now the on-board charging module of our   2018 Tesla Model S is rated at nineteen point two  kilowatts and that comes from a maximum voltage   of 240 volts times 80 amps so 240 times 80 is  19 thousand two hundred or nineteen point two   kilowatts now as most of you know there are two  different AC charging levels level one and level   two these are AC charging levels one and two and  AC charging level one is based upon a wall voltage   of a 110 to 120 volts multiplied by whatever  current your car can handle some cars have the   current set as low as 8 amps by default and if you  take 120 volts times 8 amps you'll get a whopping   nine hundred and sixty watts or 0.96 kilowatts  as your charging rate and you'll be there forever   trying to get your battery charged on that now on  most vehicles that charging level is adjustable by   default it's set to the lowest level possible so  that when you plug in your charger at your house   or apartment or whatever that you don't pop or  blow the circuit breaker the circuit breaker needs   to be rated for at least 125 percent of the charge  rate of the vehicle level to is based on a higher   voltage 208 to 240 volts so a level 2 charger  requires some specialty wiring in your house or   apartment complex or wherever it may be now the  second method of charging your high voltage DC   battery is with DC current directly and by using  DC current to charge your DC battery we bypass   the onboard charging module and just feed directly  to the battery and charge it without wasting any   power converting AC to DC on your vehicle so DC  Chargers also come in two different power levels   there's DC level one charge with a maximum rating  of 48 kilowatts and there's DC level 2 charging   with a maximum rating of 4 hundred kilowatts the  majority of DC charging stations are DC level 2   chargers I've never seen a DC level 1 charger  however Tesla vehicles with their unique charge   port utilize much of the DC level 1 charging  design and what I mean by that is if you notice on   Tesla's with their unique charge port that you can  plug in an AC charger or a DC charger and it fits   the same connector there are no pin differences  everything just plugs in and it's AC or DC so   somewhere on the vehicle the Tesla has to decide  is the Power Beam supplied AC or DC and if it's AC   then it has to use its onboard charging module to  convert it to DC before charging the battery and   if it's DC then it can feed it directly to the  battery but all with just one charge port which   is pretty cool now another thing to understand  is that the charging station that you plug into   your car which is referred to as the off-board  charger or the cord set the portable cord that   you plug into your car those do not determine the  amount of current that your car needs there's a   computer in your car that signals the off board  charger or your court set and tells it how much   current there how much power to supply to charge  the battery on the car and that amount of current   is variable based on the state of charge of the  battery and several other factors so one more   time it's the computer on the car that signals the  off-board charger or the charging station how much   current to use so you could go to a charging  station like these Electrify America charging   stations here locally and as you can see there's  chargers that are rated as high as 350 kilowatts   there's some that are rated a 150 kilowatts and  some rated at 50 kilowatts if your car can only   handle 50 kilowatts or less you could plug in  the 350 kilowatt charger but it wouldn't charge   at 350 kilowatts it would only charge at the  small amount that your car would tell that off   for charger to use as an example the Chevrolet  Bolt EV back there is rated for a maximum DC   level to charge of 50 kilowatts but it can also  handle an AC level one charge as low as 1.44kW   pretty small a level to charge as high as  seven point six eight kilowatts and a DC level   to charge as high as 50 kilowatts it's the same  vehicle you can plug different Chargers in and get   different charge rates but once again the the car  signals the charger as to how much power is you   used while charging the vehicle now if we look at  this charge receptacle from a 2019 Chevrolet bolt   EV this is considered a level two charge coupler  according to the Society of Automotive Engineers   J1772 document a lot of people call this a  CCS for combined charging system connector but   nowhere in the J1772 document does it mention  CCS or a combined charge coupler so that comes   from someplace else this charge receptacle is  referred to as a CCS type 1 charge coupler and   there's a type 2 outside the United States and  so on but when you go to a charging station you   will see the letters CCS for combined charging  system and what they're referring to is that this   electrical connector this charge receptacle is a  combination of AC charging on the top the round   part that you can see here with the five pins and  DC charging on the bottom with the two large pins   so let's explore this connector a little bit as  you can see here there are seven contact terminals   labeled one through seven contacts one through  five are used for AC level one charging AC level   2 charging and DC level one charging DC level one  charging actually uses pins or contacts one and   two to supply DC current rather than AC current  contacts three through seven are for DC level 2   charging in other words we don't use contacts one  and two during DC level 2 charging just contacts 3   through 7 now let's look at the details for these  contacts notice contact 1 and contact 2 are both   three point six millimeter diameter terminals  rated for 80 amps at 600 volts maximum contact   number one receives AC power from the l1 wire in  your wall during AC level 1 and level 2 charging   it receives DC positive power during DC level one  charging contact number two is connected to the   neutral line in your wall during charging for AC  level one charging and it's connected to the l2   line in your wall during the AC level 2 charging  and it's connected to DC negative during DC level   1 charging so once again these two terminals  contacts number 1 and 2 can be used for AC   or DC charging with 80 amps maximum at 600 volts  contact number 3 is used for all levels of AC and   DC charging contact number 4 and contact number  5 are both 1.5 millimeter 2 amp 30 volt maximum   terminals contact number 4 is called control pilot  or CPE and it uses a 1 kilohertz or 1000 Hertz   pulse width modulated signal the pulse width is a  variable signal and is controlled by the vehicle   and it's read by the off-board charging module and  so they can increase or decrease the pulse width   to increase or decrease the amount of current  being supplied to the vehicle that same line   can also be used to indicate that communication  is necessary and there's actually power line   communication available over the conductors on  some vehicles contact number 5 is used for two   things the first thing is for what is called  control status and what that means is when you   plug in your external charger to the vehicle all  of those external chargers have a release button   right there that unlocks the connector from the  vehicle well when you push in on that release   button there's actually an electrical switch in  there that opens and it signals the charger the   external charger to shut off so we know that if  you're pushing that button in that you're either   making a connection or disconnecting and while  you're making a connection it's not powered up   anyway but if this is plugged into your vehicle  and charging and you just walk up to it and hit   this button and unplug it as soon as you hit  that button within so many milliseconds the   charging system is supposed to shut down so that  you're unplugging a dead circuit and there's no   live power there so that is the control status  there now the second thing contact number five   is used for is called proximity pilot and what  that means is when you plug the external charge   cord into your vehicle it has to detect that it's  plugged into your vehicle and it does that quite   easily because in the charge connector itself in  between terminals 3 & 5 is a 2700 ohm resistor   and when you plug this in the charger has its own  parallel resistances and it'll create a certain   voltage drop and so it knows when it's plugged  into your vehicle and when it's not plugged in so   once again contact number five does two things  it detects when you press this switch and it   detects when the charge cable is plugged into the  vehicle and there's a Federal Motor Vehicle Safety   standard that says while this is plugged into the  vehicle the vehicle shall not move more than 105   millimeters I believe alright now the last two  contacts contact six and seven are much larger   terminals they are eight millimeter diameter  terminals they are rated at 400 amps maximum at   1000 volts so 400 amps times 1000 volts is 400,000  watts or 400 kilowatts and contact number six is   used for the positive side of your DC charging  contact number seven is used for the negative   side of DC charging okay starting with the 1996  version of the SAE J 1772 document as you can see   here it is called a surface vehicle recommended  practice so it's not a standard in 1996 it's a   recommended practice and that's different than an  established standard but starting with the 1996   version here and carrying through I have four of  the seven versions here I've got the 2001 which   is also a recommended practice and a 2010 which  is also a recommended practice it wasn't until   a 2016 and 17 versions of the J 1772 document  that they actually changed the name to a surface   vehicle standard so it's an established standard  so five of the seven documents that I've referred   you to in this video were just preliminary they  were recommended practices and a lot of that if   mission has changed over the years by the way the  1996 version of the J1772 document is 34 pages   long and the 2017 version that you can see here  which is considerably thicker has 116 pages so   there's a lot of information that's been added to  these now in all of these SAE documents for J1772   they refer to something called EVSE and that  stands for electric vehicle supply equipment   so we've got this term EVSE that's out  there and is being used and has got standards   set by the Jay 1772 document but I wasn't sure  where that came from so I did some research   and found out that it came from the National Fire  Protection Association and FPA it's their document   number 70 called the National Electric Code or  NEC and this is the latest NEC codebook right   here of 2020 and it's really thick and in this  book there is an article number 625 right here   and it's titled electric vehicle power transfer  system and I just want to read the very first   paragraph because it defines what EVSE means, it says  this article covers the electrical conductors and   equipment connecting an electric vehicle to  premises wiring for the purpose of charging   power export or bi-directional current flow so the  NFPA and the NEC have standards for connecting   the off-board charger to the power circuits  and then the Society of Automotive Engineers   has the J 1772 document that has the standards  for connecting the EVs II to your vehicle and   then your vehicle takes it from there and this  is for both AC and DC charging levels so the   J 1772 document has a whole bunch of standards  as to how the external charger or the off-board   charger or EVSE as its referred to interfaces  with the vehicle and there's a whole bunch of   requirements to make sure that the vehicle is not  damaged by the external charge and that everything   will work the way it's supposed to work and just  a word of caution about external chargers external   chargers need to be certified by underwriters  laboratory or Intertek here in North America   to verify that they are actually following the  SAE J1772 rules as far as interfacing with the   vehicle so that no damage will occur so if you  find a real sweet deal on a real inexpensive   external charger look to see if it has the  letters ul for underwriters laboratory or the   word Intertek listed or certified by it because  they need to be certified in order to obviously   protect your vehicle and if it's not certified  you're taking quite a chance in just assuming   that it's going to plug in and work correctly  without having any problems so be aware of that   well I know we've covered a lot in this video  on the J1772 standards in the four different   levels of charging electric vehicles and plug-in  hybrid electric vehicles but we've really just   scratched the surface of that document but it's a  copyrighted document and I can't really show you   very much you're sure very much out of that for  those of you who are interested I'll put a link   in the video description of where to download  the photograph that I put together showing you   the different terminals of the seven pin or  seven contact charge receptacle the CCS charge   receptacle I hope this video has been informative  and worth your time thank you for watching

Channel: WeberAuto

Views: 187,954

Keywords: WSU, Weber State Automotive, Weber State University, John D. Kelly, J1772, SAE, EVSE, Level 3 Charger, L3 Charger, AC Level 1, AC Level 2, DC Level 1, DC Level 2, NFPA 70, NEC, Article 625, Electric Vehicle Supply Equipment, Wheelchair, Professor Kelly, Control Pilot (CP), Control Status (CS), Proximity Detection (PD)

Id: jZBsOud4O9Q

Length: 19min 54sec (1194 seconds)

Published: Mon Nov 11 2019

Reddit Comments

[u/nod51]

Was interesting. I learned some things:

1) there is no L3, there is L1 and L2 AC and L1 and L2 DC. I never head of L1 DC being used and looks like only L2 DC has been rolled out.

2) J1772 can actually do L1 DC as well up to ~50kW at 600V. Shame Leaf couldn't have used that in 2010 instead of chademo but then it might have made J1772 plugs even more complex when having 2 ways to DC charge on a station. Really would have been nice if they had made those AC pins the same size as the DC pins so it could have been a single plug.

3) It wasn't a 'standard' till 2016 and before was a recommendation. That explains the short sighted initial design and patch to make it usable for reasonably fast charging. It is a shame they couldn't have dropped that handle and added 3 phase option (that I do most of my public charging in the USA at, see 208V), but then we are back to J3068 which I had hoped the USA Model 3 was going to use.

I really hope MCS, that is needed by semi (and IMO 150kWh+ trucks/cars), replaces the T and both CCS designs for everyone but we will see.

[u/Leather-Confection11]

Just one correction: with AC charging, it’s the AC EVSE that announces the amount of current available (in amps) to the BEV, not the other way around. AC EVSEs are basically just protective relays, so that no current is supplied if the plug is not connected to a compliant vehicle, and that will cut the power immediately due to some problem with the car, cable, or if the cable is disconnected. An AC EVSE does not interfere in any way with the energy that flows through it (apart from the relay); it’s the car that decides how much current to draw, limiting the maximum to whatever the EVSE announces through the PWM protocol.

[u/carstenhag]

Why do US people even care about what "level" it is, l1 l2 l3 etc? In Germany we just say 50kW for example. The term "hypercharger" or "hpc" is used for 150kW or higher, but there's no l1.

Also, just say "CCS" :P

[u/brippleguy]

Imo, it does not make sense to make this distinction between L1&2 and DC fast charge outside of this acedemic understanding.

Charging is so relatively complicated that we should be allowed to use "Level 3" and "DC fast" and "Supercharge" interchangeably. Arguing otherwise is gatekeeping on something we EV enthusiasts should really not want to gatekeep on.