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DucRider

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Like I said earlier, I suspect the discharge is a typo or mistake.
73.55 kWh used and 146.9 kWh to recharge just ain't gonna happen, so there is an error somewhere.

Just speculation, but it could be that the data from one of the drive unit current clamps was left out of the consumption number

The limited discharge aligns with the really low mileage though, so I'm wondering if the recharge isn't the typo.
The test is a depletion test from a full charge. Recharge info is consistent with that. They would have had to completely blow the test procedures by either not charging fully or stopping the test before the battery was empty. I find either of these a much less likely explanation.
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sierraskier

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Cold weather knocks range, but in my Model 3, snow takes it to the absurde.

Here is a drive I logged during a snowstorm last winter. The roads were covered in 2-4 inches of fresh (all 2-4" had fallen within the last hour) snow.

Consumption was a massive 813 wh/mile. At that level of consumption, my 310 miles of EPA range was only actually good for around 90 miles in the snow.

Screenshot 2021-09-28 2.42.31 PM.png


Note it was 16F at the time. My average consumption 16F weather is around 350 wh/mile. So the snow more than doubled the already elevated cold weather consumption.

Screenshot 2021-09-28 2.40.14 PM.png
DAMN, that's significant.
 

Tall_Rider

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All of the Cold weather data is for the CITY (UDDS) portion only
No data is available for hwy or the combined rating.

City 20 degrees - Conserve mode - adjusted range = 259 (actual test result = 357)
City 70 degrees - Conserve mode - adjusted range = 355 (actual test result = 491)
Where are you seeing the adjusted range? I see the 357.28, but can't find the adjusted.
 
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DucRider

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Riviandog

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Major takeaways (from Rivian EPA application docs):
  1. Confirmed 108s pack architecture using 5A (nominal) 21700 cells. Modules are 8p yielding 40A ea. Nominal voltage of 400, max charging voltage of ~450V.
  2. DCFC Max of 210 kW
  3. Testing done in conserve and sport mode (then averaged)
  4. Conserve mode absolutely disconnects rear motors
  5. Tesla method of brake pedal only engages friction brakes. Blended braking mapped to the accelerator pedal if brake hold enabled. Since the accelerator should be lifted when braking, using max regen mode will recovery the most energy when using the brake pedal.
  6. Cold weather looks to be a ~40% range hit
  7. Useable battery kWh appears to be ~129
From the docs:
  • Every vehicle which is covered by this application conforms to US EPA Federal Tier 3 Bin 0 regulations applicable to new Medium Duty Passenger Vehicles and state of California ZEV regulations applicable to new Medium-Duty Vehicles for the 2022 Model Year.
  • Maintenance schedule:
    1632852921609.png
  • 4 motors, full torque vectoring capability with 1 motor/gearset per wheel. Drive units are packaged inboard, with priority on maximizing half shaft length to each wheel to enable maximum durability and suspension articulation.
  • Front and rear drive units have high level of commonality. The motor, gearbox, and inverter are sub assembled into a drive unit to optimize mass, cost, and package spacing. The motors are the largest part of the drive unit, and the drive unit orientation in vehicle is adjusted to have the motors as low and towards the center of the vehicle as possible, reducing the center of gravity and the vehicle's polar moment of inertia.
  • Interior permanent magnet motors and water jacket cooled stator. Motor air space is a sealed "air cavity" that is shared with the Dual Power Inverter Module, DPIM.
  • Fully automatic, 2 stage, single speed reduction gearset for each wheel. Left and right gearsets share oil and a common cavity for a given drive unit. The gearsets share many parts and utilize a 12.6:1 ratio on the front and rear drive units.
  • Inverters: Front drive units are silicon carbide, while rear drive units are silicone based IGBT's. All drive units share a single capacitor for 2 motors which reduces cost, mass, and package space.
  • Drivetrain: Ball spline half-shafts are utilized to maximize half-shaft durability, efficiency, and torque capacity during high articulation suspension events. On the rear drive unit, a modular disconnect is utilized to decouple the half-shaft from the output gears such that the vehicle can operate in FWD. This allows a significant range improvement during low power output and steady state cruise driving events.
  • Battery
    • The Battery pack consists of 7,776 lithium-ion battery cells which are arranged in 9 cell modules. The 9 cell modules are assembled into a fully sealed enclosure built from an aluminum frame structure. The lid includes a removable service access panel, and the bottom plate provides protection from ground strikes consistent with the vehicle’s on and off-road capability. Liquid coolant is distributed in parallel to each cell module via the coolant manifold. A Battery Management System (BMS) communicates battery operation with other vehicle systems, controls the contactors, and monitors current, voltage, and isolation measurements. The BMS also monitors sensors for detection of gases, water, and bottom plate puncture.
    • Battery pack nominal capacity is 360 Ah based on a constant current C/5 discharge rate.
    • The thermal management system for the high voltage battery is a liquid coolant system. A pump circulates coolant thru the battery and a refrigerant-cooled chiller to extract heat and lower the temperature of the battery. In cold weather, an in-line heating element is used to heat the coolant to raise the temperature of the battery.
    • Battery management control system is programmed to prevent a state of under-voltage or over-voltage per the voltage limits defined by Rivian. Contactor opens and DTCs are set when voltage of the 9 module 135 kWh battery is below 216 V or above 459 V.
  • Regenerative Braking System
    • The regenerative braking system can use up to all 4 electric propulsion motors to convert the vehicles kinetic energy to electrical energy which is stored in the vehicles high voltage battery.
    • The regenerative control logic uses two main inputs, acceleration pedal position and vehicle speed to determine a desired regenerative braking torque. The requested braking torque is then distributed between the front and rear axles based on the vehicle state, axle disconnect status, and calculated normal force on each axle. The regenerative torque is limited when the vehicle experiences low wheel traction events (e.g. ice or snow).
    • The percentage of braking performed on road by each axle is constantly changing and redistributing. It is based on the driver demanded torque and has been optimized for vehicle dynamics and range attributes.
  • Overlap of friction brakes and regenerative braking
    One pedal driving is the default, in this mode, fully releasing the pedal yields the maximum regen level. And about halfway through the pedal travel is the neutral point, where regen is limited. As the driver manually increases primary service brake pressure and friction braking torque, the vehicle regen level will proportionally ramp down to 0 Nm based on the driver braking pressure. The ramp profile is affected by many factors. When autohold is active and the vehicle approaches standstill, the braking torque will blend from motors to friction brakes.
  • Charging:
    • AC Level 1 Charging at 120 V / 12 A
    • AC Level 2 Charging at 240 V / 48 A
    • DC Fast Charging at up to 210 kW
  • Range:
    • Tested in both Conserve and Sport modes, then averaged
    • Difference of ~12% (Slightly less impact on the hwy vs city) between the modes - Conserve Mode should get you +6% range, Sport -6%
    • Cold Weather (20 degrees F) phase (performed on the City cycle only):
      Conserve mode = -27%
      Sport Mode = -57%
      Average cold weather (city) impact -41%
A few questions answered - more questions raised

EDIT: For those looking for the documents
https://iaspub.epa.gov/otaqpub/publist1.jsp
Select "Applications" for document type and "Rivian" for manufacturer (the others are not required), then search.
The older docs have a few more details about the trucks, the newest has all the test results.

The range/test figures above are only for the R1T. I haven't looked closely at the R1S results yet but would expect them to be similar
Excellent info, was especially happy to see the testing done in cold weather down to 20deg F.
 
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