Effect of Low Temperature on Electric Vehicle Range

In the paper

“However, they set the battery's charging capability to zero and did not consider that the battery can still be charged at cold temperatures even though charging is limited.”

What the sources say

• Disputed

  Section 2.2.2 says the battery’s charging ability is strongly limited at low temperatures, not set to zero. Section 2.2.1 says the simulation models the battery-dependent availability of recuperation, and Section 3 states that recuperation is never fully restricted. The paper therefore considers limited charging rather than ignoring it. (LLM, conf=0.88)

  Checked by a reasoning model — may be wrong.

  cites [30] Lieb, 2013, Potential of an electric brake resistor to increase the efficiency of electric vehicles, World Electr. Veh. J. sourceExperimental — accuracy not yet measured

In the paper

“Cold conditions cause declined reactivity and diminished ionic conductivity in Li-ion cells [15,21], which affects their usable capacity [22] and impedance [23].”

What the sources say

• ?Not checked — no full text of the sourcecites [15] Ma, 2018, Temperature effect and thermal impact in lithium-ion batteries: A review, Prog. Nat. Sci. Mater. Int. source
• Supported

  The paper’s opening passage (indexed under Abstract; page not supplied) states that low temperatures decrease electrolyte ionic conductivity and slow charge-transfer processes, supporting the clause attributed to this source. The Influence of Laser Structuring on Cell Impedance section (page not supplied) also reports increased impedance as temperature falls. The capacity and impedance clauses have separate citations in the citing sentence. (LLM, conf=0.93)

  cites [21] Habedank, 2019, Enhanced Fast Charging and Reduced Lithium-Plating by Laser-Structured Anodes for Lithium-Ion Batteries, J. Electrochem. Soc. source
• ?Not checked — no full text of the sourcecites [22] Zhu, 2015, Materials insights into low-temperature performances of lithium-ion batteries, J. Power Sources source
• Supported

  The citation to this paper, [22], is attached to the claim about usable capacity. The Conclusion reports that battery capacity drops as temperature decreases and that poor low-temperature discharge performance affects normal capacity. The separate claims about reactivity, ionic conductivity, and impedance have other citations in the sentence. (LLM, conf=0.93)

  cites [23] Guo, S., Liu, Y., and Li, L. (2017, January 3–5). Study on the performance of lithium-ion batteries at different temperatures. Proceedings of the 2017 7th International Conference on Mechatronics, Computer and Education Informationization (MCEI 2017), Shenyang, China. source

In the paper

“On the other hand, a limited capability to recuperate at low temperatures serves to protect the battery from accelerated aging, which ultimately leads to less energy regeneration.”

What the sources say

• Supported

  Section 2.2.1 explains that low temperatures increase the risk of lithium plating, an aging mechanism, and that limiting charging consequently limits recuperation. The Abstract states that when a cold battery limits recuperation, braking energy is dissipated rather than recovered. Page numbers were not provided in our copy. (LLM, conf=0.93)

  cites [28] Steinstraeter, M., Lewke, M., Buberger, J., Hentrich, T., and Lienkamp, M. (2020). Range Extension via Electrothermal Recuperation. World Electr. Veh. J., 11. source

In the paper

“Lieb et al. [30] could demonstrate a regained range potential at low temperatures of up to 8% by implementing such an electrothermal recuperation (ETR) system in their simulation.”

What the sources say

• Partly supported

  The Introduction says the brake-resistor approach could mitigate the effect of low temperatures on driving range, and §3 reports simulated efficiency gains at low temperatures. But our copy does not report a regained driving range of up to 8%: the Abstract gives up to 12% lower total energy demand, while §3 describes up to 14% lower net energy demand under selected conditions. No page numbers are available in our copy. (LLM, conf=0.88)

  cites [30] Lieb, 2013, Potential of an electric brake resistor to increase the efficiency of electric vehicles, World Electr. Veh. J. sourceExperimental — accuracy not yet measured

In the paper

“Nagasubramanian et al. [24] showed that under extreme cold conditions (-40 • C) a Li-ion cell can lose up to 95% of its energy and more than 98% of its power capability compared to performance levels at 25 • C.”

What the sources say

• Supported

  The opening passage (p. 1) reports that Panasonic 18650 Li-ion cells delivered about 100 Wh/l at 25°C and 5 Wh/l at −40°C, a roughly 95% decrease in energy density. It also reports power density falling from about 800 W/l to less than 10 W/l, a decrease greater than 98%. (LLM, conf=0.94)

  cites [24] Nagasubramanian, 2001, Electrical characteristics of 18650 Li-ion cells at low temperatures, J. Appl. Electrochem. source

In the paper

“Since electric powertrains have a higher efficiency than conventional ones, BEVs have less waste heat available for cabin heating than ICEVs.”

• Also stated in: § 1. Introduction · plain

  “As their power is supplied by the vehicle's battery, this adds to the amount of energy consumption and thus affects the BEVs range [11,17].”

What the sources say

• Supported

  The Introduction states that ICE vehicles have large quantities of readily usable waste heat, whereas electric vehicles have less, lower-temperature waste heat and generally require additional heating. It also describes electric cabin-heater power use and a drop in the example vehicle’s range when HVAC is on; the Summary explicitly says EVs produce less waste heat than ICE vehicles. The paper gives an 85% electric-powertrain efficiency, although it does not explicitly compare that figure with conventional powertrain efficiency. (LLM, conf=0.88)

  cites [16] Doruk, 2016, New Heating System Development Working with Waste Heat for Electric Vehicles, Transp. Res. Procedia source
• Supported

  The Introduction states that, unlike fossil-fuel-powered vehicles, the heat available from a BEV’s electric motor cannot meet winter cabin-heating demand. It also says that the resulting heating energy consumption can significantly reduce range; the Conclusions report a substantial range reduction as cabin-heating demand rises. (LLM, conf=0.90)

  cites [11] Iora, P., and Tribioli, L. (2019). Effect of Ambient Temperature on Electric Vehicles’ Energy Consumption and Range: Model Definition and Sensitivity Analysis Based on Nissan Leaf Data. World Electr. Veh. J., 10. source
• Partly supported

  Section 1.2 says BEVs lack the engine waste heat available to conventional ICE vehicles and must draw battery energy for heating, reducing range. It does not state that the difference is caused by electric powertrains’ higher efficiency, as the citing sentence asserts. No page number is available in our copy. (LLM, conf=0.83)

  cites [17] Dvorak, D., Basciotti, D., and Gellai, I. (2020). Demand-Based Control Design for Efficient Heat Pump Operation of Electric Vehicles. Energies, 13. sourceExperimental — accuracy not yet measured

In the paper

“While the vehicle could regenerate no more than approximately 16% of the traction energy required for the colder trip, the figure increases to almost one fourth for the warmer trip.”

In the paper

“Since the general drivetrain design concepts and architectures of both test vehicles are the same, it was possible to merge the data (Table 1).”

In the paper

“The warmer trips require more heating energy, both in absolute and relative terms, which appears implausible at first sight.”

In the paper

“The URP shows that the vehicle could have gained an additional range advantage of 11.74% for the FTM Trip 06 and 15.11% for FTM Trip 07 when it would have used the respective predicted regenerative braking potential to the fullest (assumption: powertrain efficiency of 100%).”

In the paper

“In our analysis we found that the energy used for heating can total up to a maximum of 31.9% (Tesla) and 30.0%(BMW) of the total energy required for a trip.”

In the paper

“Our analysis showed that the recuperated energy can cover up to 42.2% (Tesla) and 38.6% (BMW) of the traction system's energy requirements.”

In the paper

“In the BMW i3, the power is between 2.5 kW and 5 kW for about 10% of recuperations, with only little recuperation occurring in higher power ranges.”

In the paper

“Only rarely is a recuperation phase longer than 20 s, while 95% of the phases are shorter.”

In the paper

“In the Tesla, on the other hand, recuperation phases with higher powers also occur, but recuperation with more than 20 kW hardly ever occurs.”

In the paper

“The fact that the Tesla recuperated highly efficiently under warm conditions is also underlined by the URP of a mere 3.46% for Rural Trip R05.”

In the paper

“The lower limits to allow any recuperation at all were found to be -4 • C (Tesla Model 3) and -1.5 • C (BMW i3), while above 10 • C no significant recuperation power limitation could be identified for either vehicle.”

In the paper

“While for the coldest of the three displayed trips (Trip R01), high amounts of unused regenerative braking potential are visible throughout the trip, but almost no unused regenerative braking potential can be identified for the warmest of the three rural trips (Trip R05).”

In the paper

“For the coldest trip, on the other hand, the visible regenerative braking restriction leads to a URP of 22.46%, and the inefficient usage of regenerative braking under cold conditions is also reflected by the regenerative braking share of just 6.6%.”

In the paper

“Compared to the RS of Rural Trip 02, which was 17.13%, that of Rural Trip 05 was 28.3%.”

In the paper

“However, both authors assessed the total range reduction of BEV's under cold ambient conditions and they did not distinguish between the different effects leading to the range reduction.”

What the sources say

• ?Not checked — no full text of the sourcecites [18] Taggart, J. (2017, January 22–24). Ambient Temperature Impacts on Real-World Electric Vehicle Efficiency & Range. Proceedings of the IEEE Transportation and Electrification Conference and Expo, Chicago, IL, USA. source
• ?Not checked — no full text of the sourcecites [19] Reyes, 2016, Winter Happens: The Effect of Ambient Temperature on the Travel Range of Electric Vehicles, IEEE Trans. Veh. Technol. source

In the paper

“Such low temperatures were not investigated as part of this study, but the trends displayed in Figure 4 indicate that the heating energy share would have been higher for our test vehicles at such low temperatures as well.”

In the paper

“While the data from trips on random routes allows just a limited, more general analysis, the data from trips on designed routes allows an extensive, comparative analysis of the low-temperature effects on the test vehicles' range.”

In the paper

“Due to power losses during the recuperation process, the PRS can never be fully achieved by a vehicle.”

In the paper

“Taggart [18] analyzed over 10,000 Tesla Model S and observed energy consumption increases of up to 45% at -10 • C, whereas short trips in particular showed higher consumptions due to the transient heating up of the battery and cabin.”

What the sources say

• ?Not checked — no full text of the sourcecites [18] Taggart, J. (2017, January 22–24). Ambient Temperature Impacts on Real-World Electric Vehicle Efficiency & Range. Proceedings of the IEEE Transportation and Electrification Conference and Expo, Chicago, IL, USA. source

In the paper

“Filtering was applied to correct the observed physically implausible profile characteristics.”

In the paper

“Besides these temporary losses in cell performance, low temperatures also promote Li-plating, which can lead to a permanent reduction in cell performance [26].”

What the sources say

• Not checked yetcites [26] von Lüders, C. (2019). Experimentelle und simulative Untersuchung von Lithium-Plating und Lithium-Stripping in Lithium-Ionen-Zellen. [Ph.D. Thesis, Fakultät für Elektrotechnik und Informationstechnik—Lehrstuhl für Elektrische Energiespeichertechnik, Technische Universität München].

In the paper

“Knowledge of the drivetrain's moment of inertia is needed to accurately estimate the vehicle's driving resistance (Section 4.4.3).”

In the paper

“Since the data used for this study was collected in southern Germany, this research is specifically relevant for regions with similar or even colder climates than Central Europe.”

In the paper

“However, since heating is not considered in RS, the determined range reductions are theoretical.”

In the paper

“Both factors can be addressed by using an additional resistance heater to keep the heat pump's performance at any time at a high level and to ensure unrestricted operation under any conditions.”

In the paper

“Furthermore, Delos Reyes et al. [19] determined their maximum range reduction under extreme cold conditions of -26 • C.”

What the sources say

• ?Not checked — no full text of the sourcecites [19] Reyes, 2016, Winter Happens: The Effect of Ambient Temperature on the Travel Range of Electric Vehicles, IEEE Trans. Veh. Technol. source

In the paper

“All trips from both datasets were conducted by the same driver, which guarantees a consistent driving style within the database.”

In the paper

“The direct comparison of trips with the same vehicle on an identical route allows for the determination of measured and therefore practical range implications, particularly regarding limited recuperation.”

In the paper

“However, it is likely that passenger comfort and weather conditions [45] also need to be considered when explaining the observed phenomenon.”

What the sources say

• ?Not checked — no full text of the sourcecites [45] Mezrhab, 2006, Computation of thermal comfort inside a passenger car compartment, Appl. Therm. Eng. source

In the paper

“Michaelidis [20], for example, showed that a BEV's heating energy demand can be reduced by up to two-thirds when a heat pump is used instead of a resistance heater to supply the cabin with heat.”

What the sources say

• ?Not checked — no full text of the sourcecites [20] Michaelides, 2020, Thermodynamics and energy usage of electric vehicles, Energy Convers. Manag. source

In the paper

“The data dispersion for similar temperatures in Figure 4 results from different trip durations and different weather conditions (see the subsequent detailed analysis).”

In the paper

“On the other hand, the results of Taggart [18] (45%) and specifically the results of Delos Reyes et al. [19] (70%), which are both based on experimental data as well, exceed our findings.”

What the sources say

• ?Not checked — no full text of the sourcecites [18] Taggart, J. (2017, January 22–24). Ambient Temperature Impacts on Real-World Electric Vehicle Efficiency & Range. Proceedings of the IEEE Transportation and Electrification Conference and Expo, Chicago, IL, USA. source
• ?Not checked — no full text of the sourcecites [19] Reyes, 2016, Winter Happens: The Effect of Ambient Temperature on the Travel Range of Electric Vehicles, IEEE Trans. Veh. Technol. source

In the paper

“Auer et al. [31] proposed a predictive thermal management system for battery electric vehicles, which utilizes navigation information of planned trips to optimize the heating strategy.”

What the sources say

• ?Not checked — no full text of the sourcecites [31] Bargende, M., Reuss, H.-C., and Wiedemann, J. (2015). 15. Internationales Stuttgarter Symposium, Springer. source

In the paper

“Horrein et al. [13] performed a simulation to show that heating requirements can cut a BEV's range by up to 30%, which is almost the same magnitude Michaelides [20] observed in his investigation simulating a sedan-style EV equipped with a resistance heater at 30 • C temperature difference between cabin and ambient.”

What the sources say

• ?Not checked — no full text of the sourcecites [13] Horrein, 2017, Impact of Heating System on the Range of an Electric Vehicle, IEEE Trans. Veh. Technol. source

In the paper

“Since steep slopes are not present on the roads driven on by the vehicles in the datasets, a positive total driving resistance means the vehicle must supply power for propulsion, whereas a negative driving resistance means the vehicle has to supply braking power to explain the observed change in velocity.”

In the paper

“The trips within the database cover a wide range of ambient conditions as well as different battery temperatures, which is ideal for analyzing the effect of temperature on the vehicles' recuperation and heating behavior.”

In the paper

“We applied a weighted moving average filter (Gaussian smoothing) to the signals since this allows noise to be captured and revised in even more dynamic sections without extensively disrupting the information in the data.”

In the paper

“Response times in the lower millisecond range: The system should have a fast response and a short ramp-up time to capture short recuperation phases below 1 s.”

In the paper

“Technical requirements for an ETR-system to reduce the identified range losses were found to be a fast response time in the lower millisecond range and a power capability of 20 kW.”

In the paper

“This is mainly caused by heating energy demands, which need to be supplied by the battery, and the reduced recuperation capability to protect the battery against accelerated aging.”

In the paper

“Power transformation of up to 20 kW: The system should be able to transform up to 20 kW of electric power into heating power.”

In the paper

“However, it should be noted that such a heater needs to be controlled directly via CAN bus and not, as is usually the case, via CAN and LIN bus.”

In the paper

“Restrictions regarding the achievable range regain with such a system still apply due to the limited energy storage capability of the heating circuit and the inability of the heater to utilize peak recuperation potential powers.”

In the paper

“other factors such as weather conditions are likely to impact the heating energy demands as well”

In the paper

“While a rapid high power transformation cannot be implemented at the air conditioning compressor, an ohmic resistance heater is able to represent such a power sink.”

In the paper

“The power of regenerative braking again illustrates the effect of the one-pedal feeling.”