Will Power Banks Explode If Left in a Car During Summer?
4 Answers
There is a possibility of explosion or spontaneous combustion under high temperatures. This is because power banks typically contain lithium batteries, which are highly prone to explosion when exposed to direct sunlight in a confined car environment where temperatures can exceed 80 degrees Celsius. Below is relevant information about power banks: 1. Introduction to Power Banks: A power bank is a device that can directly charge mobile devices and has its own energy storage unit. The main types available in the market are multifunctional power banks, most of which come with standard USB outputs. These 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 and portable high-capacity power source. It is a portable device that integrates energy storage, voltage boosting, and charging management. 2. Functions of Power Banks: The built-in charging plug of a power bank allows it to charge mobile devices directly via an AC power source while also serving as an energy storage device. It is a hybrid of a charger and a backup battery, simplifying the need for an additional charging plug compared to traditional backup power sources.
Keeping a power bank in the car during summer does pose explosion risks. I personally experienced leaving one on the dashboard once, and when I retrieved it later, the casing was scorching hot and deformed. Summer temperatures inside vehicles can easily exceed 60°C, far beyond the normal operating range of power banks. The electrolyte inside lithium batteries evaporates faster under high heat, dramatically increasing short-circuit risks. Particularly with low-quality products that have weak protection circuits, thermal runaway becomes more likely. I once saw a news report about a car in Shenzhen where the interior was destroyed by a power bank self-igniting on the center console. Now I've developed the habit of never leaving power banks in the car - safety is no trivial matter. If temporary storage is absolutely necessary, I wrap it in sunshade fabric and tuck it into the glove compartment, avoiding any sun-exposed spots.
In summer, a car turns into an oven. I once measured with a thermometer—after three hours of direct sunlight, the temperature inside soared to 68°C. Regular power banks with lithium-polymer batteries become unstable above 45°C, where casing expansion or leakage is the least concern. Fast-charging power banks with dual-cell designs face even greater pressure under high temperatures. Last year, someone in our neighborhood group even shared photos of a heat-warped power bank. I recommend choosing branded products with overheat protection, but the safest option is to avoid leaving them in the car altogether. Even for short drives, store them in shaded spots—cup holders are safer than the dashboard. After all, saving a few bucks on a power bank isn’t worth risking your car.
From a materials science perspective, power bank explosion risks are associated with four factors: poor heat dissipation of the casing leads to heat accumulation; electrolytes with boiling points below 70°C are prone to vaporization; separator shrinkage at high temperatures causes short circuits; and inferior battery cells lack temperature sensors. Once when I disassembled a discarded power bank, I found the internal circuit board had turned yellow from sun exposure. Local hot spots in a car during summer can exceed 80°C, far beyond the safe threshold for lithium batteries. Solutions include opting for fast-charge models with metal casings or installing semiconductor cooling pads in the vehicle. Of course, the simplest approach is to develop the habit of taking it with you when leaving the car, and don't forget moisture protection on rainy days.
