[10.07.20]  Everything E-Torque

This page is everything 48V e-torque related 


Conclusion Image Directory

Some Project Background
This beautiful device exists as of late 2019. Its a motor, its liquid cooled, its got a built in inverter, its automotive grade and its presently fairly low cost on the used / surplus market. Just look at that thing. Its gorgeous. Have you purchased a hobby BLDC outrunner, and found that it exploded under load? Whats the half-life of hobbyking?
While this is no where near as lightweight as a 7kw outrunner, it is comically ruggedized and has an actual coolant jacket.
Behold the savior of electric go-karts, I bring you the e-torque. 
Its a gorgeous machine
The size of a modern alternator, but with extra magic inside. The widget on the far right is a spring loaded belt tensioner
Look at that built-in controller

Hot dang that's some gorgeous silicon.

What information about this thing exists [as of 10-2020] 
What vehicle is this contraption in?
  • Dodge Ram 1500 eTorque [2019/2020] [link]
  • Jeep Wrangler eTorque [2019/2020]  [link

This presentation from Continental: [external link] [local copy] has some interesting tidbits:

This is page 9,and you can glean a bit of what the nominal setup is. You have an induction motor tied directly to the engine, so no electric-only operation. Interestingly the photo shown has the motor and inverter seperated, and looks like it was copied from an engineering diagram, as like I have eno idea why phase resistance is included. Also what is a 12v Boardnet, did you mean 12v bus?
Here's some interesting bits. This is slide 12 from the above presentation

There's a 60mm and 40mm motor, both have similar operation parameters. The continuous rating is curious, 6kw in motor mode. Lets take a look at the vehicle to figure out why. Note the coolant temperature is 115C max, which may point to these being used in-line with engine radiator fluid. Having 100C 'coolant' for an electric motor seems inherently wrong, but alas this appears to be what this is designed for. Whats exciting is that it lists -40C coolant ratings, this is norminally to indicate it can survive, canada but, it indicates that there should be no issues with some very cold weather operation on an ice-vehicle. 
From this presentation [link], from the 2017 [European Conference on Nanoelectronics and Embedded Systems for Electric Mobility]  we get a bit of an internal view of the motor, not terribly detailed, but does give us a hint at performance. 14kw peak power [2 seconds] , 4.2kw continuous [1 hr] seems to differ from the previous slides, its very likely the test conditions were with 100C coolant, as 2 seconds is an incredibly short thermal operating window.
Lets do some more digging, Infineon makes a dev-board thats eer-ily similar to the built in controller, [link]. This thing is comically similar specification-wise to the 48v inverter on the back of the eTorque motor, and may be the dev-kit it's based off of. Lets take a look at the specs.
  • 12kW 500Arms (700A peak) Output
  • 105C liquid cooling capability
  • Design for integration with Motor
So, there's a few things of interest here, 105c liquid cooling: 105c coolant is not coolant, its just the nominal radiator fluid temperature of an ICE engine. Its doubtful that an automoitive group would use an array of electrolytics, for a high temperature application, but its a reasonable place to work from. Interestingly this module is available from digikey [link], for a whopping $869.54.
Here's an interesting app-note on this thing [link] [local copy]
Can we glean any information about 48v hybrids from standards?
Enter ISO 21780, this is the 48v vehicle supply specification. I purchased a 2019 vintage draft, while the motor was likely born after this motor was manufacturered, but lets dig in anyway. The ISO bodies are incredibly protective of their standards, which for whatever reason cost money. Relevant Ycombinator Post:

 So unfortunatley I have to be vague here, from what I can tell, small excerpts are ok. Did you know the bus operating range is defined in an ISO spec?  Seriously, 60-58v is the upper overvoltage range, 58-54 is the overvoltage range, 54-52 is the 'you are entering overvoltage range' 52-36 is normal voltage range, 36-31 is the 'you are entering low voltage range' 31-24v is the undervoltage range and 24-0v is the undervoltage limit.  This is annoying, I really want to share this specification. Other interesting tidbits, at 40C, the quiescent current must be <0.1mA for the device under test. 

Does the 2020 copy show anything useful?
I had put in a library request for a copy, and while it took a few days, it appeared.

Interesting video about the e-torque system on the ram 1500 [link].
  • The stop-start feature is demo'd around 2min and 40 seconds in. 

So lets start digging public information which may help us find out at least the pinout of this monster.
Thanks to the Jeep JL forums [link]  there's some interesting wiring diagrams. Unfortunately, this vehicle is a modern monster of sensors. 

So i did the thing, I bought the actual service manual. 200$ for a manual for a vehicle I do not own. Neat. Even more curious, this is a physical flash drive, so lets see what actually shows up. The delivery window is ~two weeks, so either it is a hefty flash drive or its coming to Boston via a boat. 


(There's other photos in the photo gallery)
Concluding Remarks:

If you have questions or comments, ask below or send over an email.
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Stay safe when working with electrons in aqueous / semi-aqueous environments. Also wear sunscreen, I'm not responsible for your newly acquired winter-farmers tan : ]

Rensselaer Polytechnic Institute 
Electrical & Electrical Power