Is it dangerous to leave batteries in the car?
3 Answers
Batteries should not be left in the car under high temperatures. Batteries may explode when exposed to high temperatures. Do not charge under direct sunlight outdoors: During summer when temperatures are high, charging under direct sunlight can accelerate the aging and damage of the charger, and may even lead to spontaneous combustion or explosion. When charging batteries in summer, it is essential to avoid direct sunlight. Do not charge immediately after use: Charging the battery immediately after use can cause various components to overheat. It is advisable to wait until the battery temperature stabilizes before charging. Avoid overcharging: Overcharging can cause the battery to swell or deform, which not only reduces the battery's lifespan but can also lead to short circuits and fires due to excessive charger temperatures.
I always keep emergency batteries in my car, but safety risks must be taken seriously. Regular dry batteries may leak and corrode the interior under high temperatures, especially in summer when the dashboard can reach 60-70°C—leaked electrolyte is very difficult to clean. The most dangerous are power banks and camera lithium batteries. A mechanic friend told me they've rescued several cars where lithium batteries self-ignited due to high temperatures inside the vehicle. The 18650-type batteries are the most unstable; avoid direct sunlight whether stored in the glove box or trunk. Also, those button batteries replaced from car keys—children at home might accidentally swallow them, so remember to wrap them with insulating tape and label them. Ultimately, only keep essential batteries in the car, and take them out promptly when you get home for the safest approach.
Last time, the backup battery of my car recorder bulged in the armrest box, which made me realize this is quite particular. The 9V battery used for the reversing radar may also leak if left unused for a long time. The mechanic said the leaked potassium hydroxide can corrode the circuits. My dad always piles up car emergency jump starters in the trunk, which come with lead-acid batteries that may crack and leak acid if jolted too much. It's recommended to store them in dedicated battery boxes to prevent short circuits and avoid collisions. Enthusiasts who modify car lights should be even more careful. The parallel-connected lithium battery packs are best fixed under the rear floor, away from the fuel tank. Actually, for ordinary users, keeping a couple of AA batteries is not a big issue, mainly just avoid high-temperature areas and flammable materials.
