Can Power Banks Explode When Left in a Car During Summer?

[KiaraMarie]

High temperatures may cause explosions or spontaneous combustion. Since power banks typically contain lithium batteries, these batteries are highly prone to explosion when exposed to direct sunlight in a confined car environment where temperatures can exceed 80 degrees Celsius. Therefore, it is strongly advised not to leave power banks in cars, especially for extended periods, as this poses significant safety hazards. Below is relevant information about power banks: Introduction to Power Banks: A power bank is a device that can directly charge mobile devices while having its own energy storage unit. Currently, the main types of power banks on the market are multifunctional, most of which come with standard USB outputs. They can generally meet the charging needs of various common digital products such as mobile phones, MP3 players, MP4 players, PDAs, PSPs, Bluetooth headsets, and digital cameras. Essentially, a power bank is a convenient, portable, high-capacity power source. It is an integrated portable device that combines energy storage, voltage boosting, and charging management. Functions of Power Banks: A power bank's built-in charging plug can directly charge mobile devices via an AC power source while also having its own energy storage unit. It is equivalent to a hybrid of a charger and a spare battery. Compared to spare batteries, it simplifies the need for an additional charging plug. Compared to chargers, it has its own energy storage unit, providing a backup power source for digital products when there is no direct power supply or when outdoors.

[SadieLee]

It's really not advisable to leave power banks in the car during summer, especially in hot weather. I've seen too many similar cases where temperatures inside a closed car can easily soar above 60°C under direct sunlight, much hotter than the high-temperature warnings in weather forecasts. Lithium batteries undergo chemical reactions when exposed to high temperatures, generating a large amount of gas inside that causes the casing to expand. In severe cases, they can explode and catch fire. Last year, there was a local case where a car owner left a fully charged power bank under the windshield, and when they returned, the glass had been shattered by the explosion. I recommend developing the habit of checking your car before leaving, not just for power banks but also items like lighters and aerosol cans—don't leave them in the car. If you absolutely must leave something, at least avoid placing it on the dashboard or seats. The shaded area in the trunk might be slightly cooler, but for safety's sake, it's better not to take the risk.

[VonOscar]

From the perspective of battery principles, the lithium ions in power banks are highly sensitive to heat. Based on my experience in product design, the electrolyte begins to decompose when temperatures exceed 45°C, and thermal runaway may occur above 65°C. When a car is parked under the sun, the dashboard temperature can easily surpass 70°C within minutes, turning the power bank into a potential time bomb. Many people consider explosions to be low-probability events, but battery swelling is quite common—I've personally witnessed a friend's power bank ballooning after sun exposure. It's crucial to warn car owners that some power banks use inferior plastic casings, which are more prone to deformation and electrolyte leakage under high temperatures. Additionally, aged batteries pose greater risks—a three-year-old power bank has completely different heat resistance compared to when it was new. Whenever possible, park in shaded areas or underground garages to reduce ambient temperature by about 10°C.

[EverettLynn]

I personally experienced a power bank swelling. During the hottest week last year, I left my frequently used power bank on the back seat, and after three hours, I found its casing deformed and soft to the touch. I was so scared that I immediately used a clip to move it to a shaded area to cool down, and since then, I never leave electronic devices in the car. In summer, car windows act like magnifying glasses, and the temperature in areas exposed to direct sunlight rises extremely fast, especially in cars with black interiors that absorb more heat. Now, I hang my power bank with my keychain and take it with me before locking the car. A friend also taught me a trick: if you really forget, don't directly touch the hot power bank—open the car door to ventilate for ten minutes, then wrap it in a wet cloth before removing it.