Chevrolet Bolt EV High Voltage Components

Hello I'm professor John Kelly and this is the  WeberAuto YouTube channel in this episode we are   going to look at the high voltage electrical  system on our 2007 Chevrolet Bolt EV now our   Bolt EV here is brand new a year ago it only has  about 30 miles on it but we have disassembled   everything under the hood that can be disassembled  in relation to the traction motor or the inverter   the onboard charger the DC to DC converter of the  junction block the air conditioning compressor the   high voltage battery heater we've got the high  voltage battery out front of the car and if you   look here we've even got the charger poured out  ours did not come with DC fast charge I've got   DC fast charging to try to put on this to do a  conversion but I'm not sure that it'll work now   if we look underneath the hood of the vehicle here  and compare this to the this photograph of how it   looked before we disassembled it you can see that  everything is gone that it's totally empty the   radiator that was in the front here is only for  the traction motor and the power electronics there   is a separate cooling loop under the hood here  for the battery the battery cooling is not done   at all through the radiator to my surprise it only  has a battery chiller through the air-conditioning   system that we'll look at in a future episode the  only high-voltage component I did not remove for   this episode is the heater coolant heater so while  you were driving down the road if you want heat in   the passenger compartment when the weather is cold  this heater assembly is a high voltage heater it's   got the orange cable right here and it heats up  the coolant that is circulated through the heater   core up underneath the hood here so it goes into  the passenger compartment into the heater core   comes back out the coolant reservoir right here  one of three reservoirs under the hood is just   for the heater coolant so there's a loop there and  us and a little pump that pumps the heated coolant   through your heater core this reservoir right here  is for the battery cooling and this one right here   is for the motor and electronics cooling this  vehicle uses the are 1 2 3 4 YF refrigerant   in its air-conditioning system and so it takes  this special air conditioning recovery recycling   machine as you can see in this photograph here  this refrigerant is very expensive and there's   special procedures of handling that refrigerant  special training just for that so the air   conditioning system on this car obviously cools  the air in the passenger compartment but it's   also responsible for cooling the battery whenever  it's it's too hot whether that's from charging or   just from driving and there's a separate battery  heater that will heat it up when it's too cold   while charging all right well let's go take a look  at all these components that we've removed from   under the hood see what they are talk about what  they do see how they're all interconnected with   the big orange high-voltage wires and how they all  end up connecting back to our high voltage battery   ok here on the table we have the drive unit which  is comprised of the electric motor the traction   motor and the gear reduction unit that make up  the propulsion system for the 2017 and above   Chevrolet Bolt EV now I will have a separate video  on the disassembly and inspection and reassembly   of this this drive unit is liquid cooled it has  an inlet and an outlet pipe there for coolant   and it just uses regular General Motors Dexcool  50/50 mix coolant the lubrication for this drive   unit is automatic transmission fluid the Dexron HP  fully synthetic dextran HP automatic transmission   fluid and this holds 2.9 liters of this fluid  also while we're here on the motor there are   two excellent society of automotive engineering  technical papers that you can purchase I can't   show you these because they're copyrighted but  they have fantastic information on the design   and operation of this drive unit and of the entire  Chevrolet Volt evie powertrain both of these were   presented in April of 2016 one of them is called  the design of the Chevrolet Volt evie propulsion   system the other one is called electric motor  design of General Motors Chevrolet Bolt electric   vehicle so some great additional information if  you're looking for technical details on these on   this system so this motor has is rated at 150  kilowatts which is roughly 201 horsepower it's   also rated at 360 Newton meters of torque which  is approximately 266 pound feet of torque and it   has a maximum rpm of 80 810 rpm which for the tire  size on the Bolt EV puts the maximum vehicle speed   according to the limited inter motor rpm here  at approximately ninety four point six miles per   hour it has a seven point zero five one eight to  one gear reduction unit the drive unit itself is   designed so that it's dead center in the middle  of the vehicle that means the CV shafts here on   each side are equal lengths and as a matter of  fact they are exactly the same part number of CV   shaft and that's to eliminate torque steer upon  heavy acceleration I'm going to remove these CV   shafts and then we'll we will start bringing in  the rest of the electrical high voltage component   that are used to control this drive unit and the  rest of the high voltage system on the vehicle now   this drive unit is mounted to the lower support  cradle in the front of these Chevrolet Bolt EV   but right above that is a big steel bracket that  supports all of the electronics that you see when   you look under the hood so I'm going to bring  that bracket over and set it here on top of the   motor I've got these floor jacks and other stands  here to help hold it in place while we build this   high voltage system so this big bracket here  is called the under hood cross car beam and   like I said it holds all the electronics  on top or above the electric motor itself okay I've now got the underhood cross carb beam  installed besides holding the power electronics   to control the drive unit it provides structural  support in the front of the bowl TV to make it   stronger during a collision this under hood cross  car beam as you can see has several ground wires   attached to it this one goes to the DC to DC  converter for our 12-volt system the rest of   these attached to the electric motor drive unit  and the chassis of the vehicle to connect our 12   volt systems ground to the DC 2 DC converter  in the end the cross car beam as well as the   housing of the drive unit itself now in order  to make the electric motor rotate we have what's   called a single power inverter module or spi  M so I'm going to bring the spim these single   power inverter module over next this is the single  power inverter module or the spim as you can see   it is also liquid cooled we have a low voltage  connection in the front we have a power feed   from an under hood junction block that connects  to the high-voltage battery so we have the two   wire DC coming in and then in the back here as  you can see we have the three-phase electrical   connection going out that will feed power to our  three-phase electric motor in the drive unit this   particular inverter that I have right here is  one I purchased off of ebay and I've taken it   I've taken the lid off of it and I will take this  apart in a different video and explore what parts   are inside of it but I imagine it's just a typical  inverter with the typical pieces in it I'm pretty   sure it does not have a boost converter inside  of it to boost the voltage up but I don't know   yet I still need to take it apart so this power  single power inverter mod sits right up here on   this under hood cross car beam now if you open  the hood on your Chevrolet Bolt EV and look down   inside you'll be able to see the front of this  single power inverter module but on top of that   is another module this one right here this one  is called the high power distribution module or   HP DM and basically what this does is it receives  power on these two big terminals right here from   the high-voltage battery and then can transfer  that to the inverter module here on the side   with the connector it can sent it to the heater  coolant heater to heat the coolant that goes   into your heater core on cold days and that's up  underneath the hood there are four other connector   connectors here on the side of this distribution  module we have one for the air conditioning system   one from the onboard charger when you plug in  your external charger to the car to charge the   battery one going to the battery itself for  charging the battery and then one that goes   to the heater that heats the coolant that goes  into the battery on cold days now on the front   of this there is no electrical connector but if  I had one that had fast charging it would have   an electrical electrical connector right here  let me get one that does okay so here is a high   power distribution module that has the electrical  connector on the front for fast DC charging so   here's the other one out of our Bolt EV that does  not have the fast charging here's one that does   have the fast charging other than that externally  all the connections are the same the one that has   the fast charge connections if we take the lid off  of this thing and look inside it actually has two   additional contactors that basically connect  these two big heavy terminals for your DC fast   charge right through this distribution block and  connect it right to the two terminals the large   terminals that go to the high voltage battery to  charge the battery and so it bypasses everything   else and just goes right through to for a fast  charge on that battery all right now I found   this high power distribution module on on ebay  for the fast charge option and so I'm going to   put that back on our Bolt EV over here and attempt  with additional other pieces that are required to   convert ours to fast charge I've heard from some  people that have tried this and said they could   not make it work so I don't know if I will be able  to either but we're going to try it so the high   power distribution module the HP DM goes right up  here on top of the single power inverter module so   now when you open the hood and look you can see  the top of this high power distribution module   sitting right there so we've got two of the four  modules installed on this cross under hood cross   car beam right above the electric motor now the  next module that goes down on the this beam here   is the onboard charger and when they say onboard  charger that means when you plug in your j17 72   charge cable whether it be on 120 volts or 208  or 240 volts that's an AC voltage it has to be   converted to DC to charge the DC battery but all  of those voltages are lower than this battery's   350 to 400 volt range and so then they also have  to step up the voltage to be a high enough voltage   to actually charge that battery so the onboard  charging module the OB CM does a lot and it is   also liquid cooled let me get it so this is the  onboard charging module as you can see it is also   liquid-cooled and then here on the driver's side  it has three electrical connectors this bottom   one is AC voltage in from the charge receptacle  this black one is low-voltage for control and   this top one here is DC output that then would go  to our under hood distribution module and then go   charge the battery the high voltage battery  on the smaller of the two orange connectors   on the battery so now I'm going to put this on  board charging module up here on the under hood   cross carbine okay it's fairly heavy awkward  angle so this is our on board charging module   it bolts to the under hood cross car beam and  has electrical connectors there on the driver's   side okay the next module that goes on that you  can see under the hood directly is the accessory   power module the APM and basically this is a DC  to DC converter and basically what this does is it   takes high-voltage from the battery which could  be upwards of 400 volts and it has to step it   down and output roughly 14 volts 13 and a half  14 volts to charge the 12-volt battery and the   12-volt system on the rest of the vehicle because  it's that 12-volt system that controls the high   voltage system on these on all of these hybrid and  electric vehicles so we have on this end here a   14 volt output this is our the equivalent of the  ground that would then go to the battery negative   so this is go to battery positive this is go to  battery negative through the on car cables there   as you can see here it is also liquid cooled so a  lot of liquid cooling going on here this accessory   power module just sits right up here right there  I'll hold that in place with a couple of bolts   okay these are the four major components that you  can see under the hood of your Chevrolet bull when   you open it we've got the high Power Distribution  module right here underneath that is the single   power inverter module that drives the drive  unit electric motor down below we have our our   accessory power module the APM which is a DC to DC  converter and right below that we have our onboard   charger module to take the wall voltage when you  plug in your vehicle to charge it and change it to   a high voltage DC to charge the battery now we've  got two other high voltage electrical components   to bring in and then we can start connecting  the wires on these to show how they are all   electrically connected together okay the next  high voltage component to add to our workbench   mock-up here of the bull DV powertrain is the air  conditioning compressor module the AC CM so it has   a two wire DC high voltage electrical connector  that comes in to the module end of the electric   air conditioning compressor where it has its own  inverter it's going to take this DC voltage and   change it into a three-phase AC voltage to drive  a variable speed air conditioning compressor this   compressor of course is used to cool the passenger  compartment but it is also used to cool the high   voltage battery there is no radiator for the  cooling of the battery it only uses what's called   a chiller where the air conditioning system has  this little mini evaporator that the coolant for   the battery runs through where removes the heat  from the coolant and then runs that out to the air   conditioning condenser in front of the vehicle and  radiates that eat away so this a air-conditioning   compressor module sits right on the drive  unit right in front of the drive unit here   I'm on a stud and a couple of bolts holding it in  place okay so now we've got our air conditioning   compressor module with its high voltage connection  that's going to stick out the back over here that   leaves us with one more high voltage component  that we need to bring in for the full evie system   all right this last component here is the battery  coolant heater they call it the rechargeable   energy storage system heater so they don't call  it a battery they call it our ESS the rechargeable   energy storage system and so it has two coolant  lines right here and right here that connect it   has a high voltage connection right here there's  a big heating element inside there's a temperature   sensor right there and some ground wires connected  to it and this is also eventually connected back   here to this high power distribution module but  through the big harness and so this sits over   here in back of the drive unit so it's going  to sit right right about here and it's bolted   to hold it to the frame to start connecting all  of these components together we have one three   wire wire harness right here and this is for  the three phase voltage control of the drive   unit and so this upper end right here is going  to connect to the single power inverter module   the lower connector here is going to connect to  the drive unit in the back so let's hook this up   okay to connect it got a couple of studs on the  inverter side and three bolts and then here on   the motor side we also have three more bolts by  the way none of these systems have live voltage   on them the battery that has all the powers over  next to theBolt EV and here in the shop all of   these wires even though they're orange and I'm  not using any personal protective equipment on   them there's no voltage on them there's no danger  when you're when you've got these components off   to the side and they've already been verified that  there's no voltage on them okay so here on the   back of the single power inverter module we have  three-phase cables the UV and W cables that come   down to our drive unit electrical connector and  they bolt in place they have nice weather tight   seals and that this is the only these are the  only three phase AC voltage cables that you'll   see on this vehicle all these others are two wire  DC voltage so if you see three wires right next   to each other like that going to a motor those are  AC voltage wires if you just see two wires next to   each other like these then those are high voltage  DC connections okay the next electrical harness   to connect up is a u-shaped great big thick wire  heavy gauge wire electrical connectors and what   this does is this will connect the high power  distribution block electrical connector down to   the power inverter module electrical connector and  they just have a little latch lever on the side so all that does once again is connect the  distribution module to the power inverter giving   the power inverter DC power from the high-voltage  battery okay the next big wire harness to connect   is the wire harness that connects at the battery  itself to provide power to the inverter it also   has two additional small electrical connectors  down on the bottom one that goes to the battery   heater one that goes to the charge port on the  battery itself the smaller of the two electrical   connectors for the DC charge the 7.2 kilowatt  hour AC charger that's connected to the onboard   charging module here under the hood so here on  the back of the power inverter module we have a   great big electrical connector that's going to  come in right there snap into place it also has   two small electrical connectors right here one of  them or they both go to the distribution module   right up here the upper electrical connector  is what connects to the battery heater down   below here so I will connect the harness connector  underneath the vehicle to the battery heater this   second connector up here the lower of the two then  goes to the battery charger the AC battery charger   connection on the high voltage battery so under  the car we only have two electrical connectors   the great big one that's for feeding power to the  power inverter module and regenerative braking   power back to the battery well as you drive this  also is the practical connector that is used when   you connect up the DC fast charge connector  to the vehicle it will charge directly through   this large electrical connector rather than the  small electrical connector back here this one is   only for when you plug in your J 17:70 to charge  connector the other one is the the combo the the   J 1772 combo connector okay we've got another  high-voltage electrical harness here on this   end these two electrical connectors connect to  our high Power Distribution module on these two   empty electrical connectors so let me plug those  in and then the other end of this harness goes   around back this upper cable right here feeds  power to our accessory power module to convert   the high voltage DC to low voltage DC so that's  our DC to DC converter this lower connection   here is the DC feed out of our onboard charging  module so after it's already converted from AC   to DC and stepped-up in voltage then it goes up  to the distribution module and then fed back to   the battery on this small electrical connector  right here and then this last connector is the   one that connects to our air conditioning control  module up in front of the drive unit so we've got   a number of electrical connectors here all of  these are DC except for these three right here   with your three-phase AC now the only harness left  is our plug in charge connector harness so let's   take a look at those options next okay the plug  in charger that came on our Bolt EV the charge   connector looks like this one and notice it does  not have the orange door and the two additional   DC high-voltage electrical connections there but  if we look at this other one that I bought you can   see that it does have the little door right here  and opens up and you've got the two high voltage   electrical connectors right there those two high  voltage terminals connect to this great big wire   harness right here and they come up under the hood  and connects right here to the front of our high   power distribution module just like that so the  when when we plug in the CCS combo charger which   is the J 1772 on the top and the two pin DC down  below it will already have a DC high voltage DC   applied to these wires where it then goes to our  distribution module and goes directly through to   the back and right back down to the battery itself  for a quick charge so when you charge using the   high voltage DC fast charge it does not use the  onboard charging module to charge the battery   now it goes through this distribution block here  as I mentioned it also in that distribution block   powers up some other systems on the vehicle like  the air conditioning compressor module if needed   to cool the battery while it is charging and  a few other systems for monitoring and so on   the one thing it does not power up to my surprise  if necessary in cold cold weather is the battery   heater so maybe there's some problems with fast  charging a really cold battery and you just simply   plug in your your fast charger I've heard from  people that have the ball TV with the fast charger   you plug it into the fast charge when that's cold  then it won't charge you have to plug in the AC   the slow charge the J 1770 to charge complaint  charge connector and it actually tells you that   in the owner's manual it says below a certain  temperature the fast charge isn't going to work   by the way this fast charge connector here has an  additional solenoid and a lock in the connector   here that will lock the the CCS combo connector  charge connector in place while it's charging   DC high voltage and it won't let you unplug it  until it's verified that everything that all the   voltage has been removed from these terminals and  so there's a to convert to a fast charge both evie   you need more than just this harness connector  here and the the the distribution module there   is a low voltage wire harness that is totally  different let me bring that in okay this is the   low voltage under hood wire harness and in the  electrical connector that goes to this module   right here the the high-powered disconnect  module this electrical connector if you look   at it right now it only has one two three four  five wires in the back of that connector the one   for the DC fast charge has every wire in there  except one and so this one is missing three on   the top and four on the bottom so there's seven  potential wires more that it could have the one   with the DC fast charge has six more wires in it  and I'm sure that has to do with monitoring the   voltage so that we can unlock the charge connector  there when when it's done charging and I've looked   at the wire harnesses this goes all the way in  to the hybrid powertrain control module number   two under the passenger seat and so there might  even be a different in eternal wire harness which   makes me wonder if this can even be done without  changing all kinds of parts and whether or not the   programming is is even able to be done you know  just because you buy all the parts doesn't mean   that the modules will configure themselves to  be fast charge I'm going to keep playing with   it and see but from what I've heard it does not  work when you do that but it could be that maybe   whoever's I was communicating with about that  conversion didn't realize that there was this   wire harness difference as well so let's just  do a quick review and then we'll be done we've   got the drive unit of the Bolt EV right here  I'll have a separate video on disassembly and   reassembly of it that drive unit is controlled  by the power inverter module that's underneath   the hood the power inverter module receives its  power from the battery through this high power   distribution module right above it that you can  see under the hood over here we have our DC to DC   converter where we have our ground cable that is  going to come in and bolt right there we have our   power cable that goes to our 12-volt battery and  a ground cable for the 12-volt battery as well so   that's our accessory power module right underneath  that we have the on-board charging module for when   you plug in the high-voltage charger to the side  of your car we also have the either the quick   charge plug in connector receptacle or the non  quick charge version like the one our car came   with as a high voltage component we've got the  air conditioning compressor module the bolts to   the front of the drive unit and then in the back  we have the heater module for heating the coolant   going into the battery and then the one module  I did not bring over from the car is the heater   for the coolant that goes into the heater core  to heat the passenger compartment on cold days   so these are all of the high voltage components  that are there involved with the Chevrolet Bolt   EV with the exception of the high voltage battery  and if you look at the high voltage battery here   I have a separate video on complete disassembly  and reassembly of this battery but we've got the   two orange electrical connectors on the front  the great big one is for DC fast charge and   feeding the inverter the small one is for the  plug-in charger the little black ones are for   low voltage connections and then of course it's a  liquid-cooled battery so we have the two coolant   pipe one for the inlet and one for the outlet all  right so this has just been a basic review of the   Bolt EV high voltage electrical systems I plan on  having a video on the disassembly of every one of   these components here coming up I still need  to finish my history of automatic transmission   fluid videos before I dive too far into this  but the classes I'm teaching here at Weber   State University made me interrupt my automatic  transmission fluid history video shooting and   get to this because we are towards the end  of the semester and this is what I wanted to   show my students before they left for Christmas  break so that is it thank you for watching you

Channel: WeberAuto

Views: 161,817

Keywords: R1234YF, NACAT, Guy in wheelchair, DC-DC Converter, Bolt EV, John D. Kelly, ASE, DC Fast Charge, Traction Motor, High Voltage, Drive Unit, Battery Heater, Inverter, Weber State University, CAT, J-1772, NATEF, On-Board Charger, Chevrolet, GM, APM, #Electricvehicles, Professor, STEM

Id: 5gDILvW5yMg

Length: 35min 56sec (2156 seconds)

Published: Wed Dec 05 2018