Winter's harsh conditions can put a significant strain on electric vehicles (EVs), affecting their driving range and charging efficiency. A recent experiment conducted by a Swedish Tesla Model Y owner has shed light on the substantial difference in rapid charging times between a preheated and cold battery during cold weather. These surprising findings underscore the crucial role of battery preconditioning in optimizing EV performance, especially in colder climates.
The Significance of Battery Preconditioning
Preconditioning the battery by bringing it to an optimal temperature before charging not only prolongs its lifespan but also maximizes driving range and reduces charging time. This process ensures safe charging by heating the battery above freezing, allowing for maximum charging current. While slightly higher energy costs may be incurred, the benefits of battery preconditioning far outweigh any potential drawbacks. The EV community is increasingly recognizing the importance of this feature, as EVs become more prevalent in colder regions.
The Swedish Tesla Model Y owner conducted a winter charging experiment, comparing the charging performance of a preheated battery to that of a cold battery in freezing temperatures. The experiment, documented on the It’s Only Electric YouTube channel, took place at a Tesla Supercharger V3 station. The charging session began with the battery preheated to -1 degrees Celsius (30 degrees Fahrenheit) and a 10% state of charge (SoC). The results were striking, with the preheated battery reaching a power output of 238 kW, completing a 10% to 80% SoC session in just 33 minutes.
Comparing Cold vs. Preheated Battery Charging
Returning to the same charging station two days later, with the car exposed to even colder conditions (external temperature -4°C), the experiment was repeated with a cold battery. The charging speed was significantly slower, taking 42 minutes to complete the 10% to 80% SoC charging, nearly 10 minutes longer than the preheated battery. Moreover, the maximum charging power accepted by the cold battery was drastically reduced, reaching only 135 kW compared to the 238 kW in the previous test.
Analyzing the charging curves of both scenarios revealed a stark contrast, highlighting the efficiency of preheated battery charging during the initial stages. The preheated battery experienced a much faster charging speed during the first half of the session, displaying a nearly flat curve for the 50% to 80% SoC range. The cold battery, on the other hand, exhibited a descending curve, indicating a slower and less efficient charging process.
The Verdict on Winter EV Charging
Based on the test results, preheating your EV battery before winter charging sessions is unequivocally recommended. Achieving effective and rapid charging while preserving the battery’s health becomes essential in colder climates. Potential EV owners should ensure that the preheating feature is available in their chosen model, as it may not be a standard offering across all EVs.