The Rivian R1T is the next all-electric vehicle that we will analyze in terms of fast charging capabilities.
Data for the analysis comes from one of Kyle Conner’s test, for the Out of Spec Reviews channel, performed at an EVgo fast charging station.
It’s not necessarily the perfect charging session, because according to the video, the battery was a bit cold, but it shows a full 0-100% state-of-charge (SOC) range. The results are better than achieved in a short TFLEV test.
In a later part of the video, Kyle tried to explore other charging sessions to determine the theoretical peak charging characteristic, but our focus in only on the first session.
It’s worth noting that to achieve the best results, the R1T has to be charged at a charger that can supply up to around 450 A at over 400 V (for a peak of up to around 200 kW).
Let’s crunch some numbers and see whether the fast charging results are as amazing as the overall specs of the vehicle.
Charging power vs state-of-charge (SOC)
According to the data obtained from the 0-100% SOC test in the video (charger’s display), the charging curve is relatively flat up to about 58% SOC.
The peak charging power was about 184 kW at about 16-17% SOC, compared to about 200 kW expected. In some of the other charging sessions, Kyle was able to achieve close to 200 kW.
In the upper third, the charging power is much lower. At about 80% SOC, it stuck at around 51 kW for quite some time, before further decreasing at around 90% SOC. It’s clear that there is not much value in charging to a high SOC if it’s not necessary to reach a destination/another charging point.
According to the charger, the total energy delivered to the car was 137 kWh, compared to the 123 kWh displayed by the car as added energy.
State-of-charge (SOC) vs time
The charging session from 0-100% took 1 hour and 31 minutes (aside from an interruption due to the 60-minute session limit), but the more important values are:
- 10-80%: 42 minutes
- 20-80%: 37 minutes
- 10-90%: 56 minutes
- 20-90%: 51 minutes
Charging from 20% to 80% SOC took about 37 minutes.
Average charging power vs state-of-charge (SOC)
The average power in the very important range from 20% to 80% SOC is 124 kW, which is 68% of the peak value.
If we study the chart carefully, we can notice the green area – the most optimum for charging – which ends at about 65-70% SOC.
C-rate vs state-of-charge (SOC)
The peak C-rate* – charging power in relation to the battery capacity of 135 kWh – is about 1.36C.
The average C-rate when charging from 20% to 80% SOC is 0.92C. Both numbers are not specifically high compared to many other electric vehicles.
*C-rate tells us how the charging power relates to the battery pack capacity. For example: 1C is 1-hour charging power (current), when the power value in kW is equal to the battery pack capacity in kWh. 2C would be enough to recharge in half an hour.
We don’t know the official value of net battery capacity, because the manufacturer communicates only the 135 kWh value, but the car’s display showed 123 kWh added when charging from 0-100% SOC.
In the previous range test, the car displayed 124 kWh of used energy from 100% to nearly 0% SOC. 123-124 kWh would be 91-92% of the total of 135 kWh.
Range replenishing speed vs state-of-charge (SOC)
The rate of range replenishing depends on the energy consumption and the energy consumption depends on the use case.
Assuming EPA numbers, we can calculate the estimated rate of range replenishing, however, we must remember that the real world rate is lower (due to charging power reported by the charger before losses and auxiliary vehicle loads):
- EPA Combined range
Taking into consideration the EPA Combined range of 314 miles (505 km) and available battery capacity of 124 kWh, we can assume energy consumption of 395 Wh/mile (245 Wh/km).
The effective average speed of range replenishing when charging from 20% to 80% SOC would be 5.2 miles/minute (8.4 km/minute).
- EPA Highway range
Taking into consideration the EPA Highway range of 292.9 miles (471 km) and available battery capacity of 124 kWh, we can assume energy consumption of 423 Wh/mile (263 Wh/km).
The effective average speed of range replenishing when charging from 20% to 80% SOC would be 4.9 miles/minute (7.9 km/minute).
Nonetheless, to achieve around 6 miles/minute, we should end charging before 60% SOC.
Ultimate DC fast charging card
Here is our ultimate charging card for the Rivian R1T that shows an estimated time of charging to add a certain number of SOC percent points, average charging power, added energy, and added range for listed SOC ranges.
The matrix above, might be helpful from the user perspective, but be aware that it’s just an estimate from a particular test, with measure and calculation uncertainty probably above 5%. On top of that comes variation for individual case – car (version, age/battery state-of-health), charger, ambient and battery temperature, software version and more (including cabin heating/cooling during charging). Another thing is that the charging curve might shift when charging starts at a lower/higher SOC.
Considering the above results, Rivian R1T’s fast charging capabilities are kind of “ok” – for sure, not state-of-the-art, especially because we are talking about a large 135 kWh battery.
There is room for improvements, including the increase of peak power and power above 60% SOC as well as the switch to an 800 V battery system (which is coming in the future). Charging power at about 50 kW between 80 and 90% SOC seems too low (low C-rate), and might be disappointing for some who need more range on their adventures.
For now, fast charging is a weaker point of this outstanding vehicle. Because R1T is the first modern all-electric pickup on the market, and the first from Rivian, let’s hope it will improve.
|2022 Rivian R1T (QM AWD, 135 kWh) :: DC Fast Charging Summary by InsideEVs|
Drive: AWD; Battery pack : 135 kWh
[Data source: Out of Spec Reviews]
Average Power (20-80% SOC)
Time (20-80% SOC)
|Range Replenishing Speed (Average 20-80% SOC):|
|8.4 km/min (5.2 mi/min)|
7.9 km/min (4.9 mi/min)
* Some values on the charts are estimated from the data source.
** Temperature of the battery cells might highly negatively affect charging capabilities. We don’t have data about temperatures of the battery at the beginning and during the charging process. In cold or hot weather, as well as after driving very dynamically, charging power might be significantly lower than shown on the charts (in extreme cases charging might be impossible until the battery temperature will not return to an acceptable level).
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