Electric vehicles (EVs) are known for their efficiency, but their performance can be significantly affected by ambient temperature. Lithium-ion batteries, which power most EVs, operate most efficiently within a specific temperature range, typically between 68°F and 77°F (20°C and 25°C). When temperatures stray too far from this ideal range, the EV’s range can decrease noticeably. Extreme cold has been widely studied, often showing EVs struggling to achieve even half their claimed range in winter conditions. However, the impact of extreme heat is less frequently examined. A recent test aimed to address this gap, revealing interesting insights into how EVs perform in scorching conditions.
To investigate the effects of extreme heat on EV range, _What Car?_ conducted a test in southern Spain, one of Europe’s hottest regions. Three different EVs were selected for the test:
Both the Kia EV3 and the Tesla Model 3 have liquid thermal management systems for their batteries and heat pumps, offering more sophisticated temperature regulation compared to the Citroen e-C3’s air-cooled system. The vehicles were driven at highway speeds, a condition where EVs are generally less efficient. The peak temperature during the test reached a sweltering 111°F (44°C).
The test revealed that all three EVs fell short of their official WLTP range ratings due to the combined effects of high speed and extreme temperatures. Here’s a breakdown of the results:
The Tesla Model 3, despite having the best energy efficiency, experienced the largest percentage decrease in range. This outcome suggests that while the Tesla is efficient in terms of energy use, it is more susceptible to range reduction in extreme heat compared to the other vehicles tested. The Tesla range loss is a key finding for potential buyers in hot climates.
| Vehicle | Official WLTP Range (miles) | Observed Range (miles) | Range Reduction (%) | Efficiency (miles/kWh) |
|---|---|---|---|---|
| Citroen e-C3 | 199 | 142 | 28.7% | 2.7 |
| Kia EV3 | 362 | 246 | 32% | 2.9 |
| Tesla Model 3 Long Range | 436 | 244 | 44% | 3.0 |
An unexpected aspect of the test was the charging performance of the vehicles in the extreme heat. Both the Kia EV3 and the Tesla Model 3 demonstrated resilience to the high temperatures, charging relatively quickly and closely matching their official fast charging times (10% to 80%). The Tesla Model 3 charged from 9% to 80% in 32 minutes, just slightly longer than its claimed 27 minutes. The Kia EV3 went from 10% to 80% in 31 minutes, only 3 minutes off its claimed time. In contrast, the Citroen e-C3, with its less sophisticated thermal management, struggled. It charged at a maximum of 38 kW, taking 74 minutes to charge from 3% to 80%.
This suggests that while extreme heat significantly impacts range, advanced thermal management systems can mitigate the effects on charging speed. The Tesla’s charging performance remained robust, despite the notable range loss, highlighting the effectiveness of its thermal management system in maintaining charging efficiency.
| Vehicle | Charging Power (kW) | Charge Time (10-80%) |
|---|---|---|
| Citroen e-C3 | 38 | 74 minutes (3-80%) |
| Kia EV3 | – | 31 minutes |
| Tesla Model 3 Long Range | – | 32 minutes (9-80%) |
This extreme heat test provides valuable insights for EV owners and prospective buyers, particularly those in warmer climates. The significant range reduction experienced by all vehicles underscores the importance of considering ambient temperature when estimating EV range. While the Tesla Model 3 demonstrated the largest range loss, its charging performance remained relatively unaffected, showcasing the benefits of advanced thermal management systems. Factors such as the Tesla’s glass roof, which necessitated increased air conditioning use, may have contributed to its greater range reduction. Ultimately, this test highlights the need for realistic expectations regarding EV range in extreme conditions and emphasizes the importance of efficient thermal management for both range and charging performance.
For those living in areas with consistently high temperatures, it’s crucial to factor in potential range reductions when planning trips. Additionally, the test results suggest that investing in EVs with robust thermal management systems can help mitigate some of the adverse effects of extreme heat. The Tesla range loss serves as a reminder that even technologically advanced vehicles are not immune to environmental factors.
