* Contamination: Rainwater is not pure. It can contain impurities like dirt, dust, and minerals that can damage the battery's plates and electrolyte.
* Corrosion: The water in rain can be acidic, leading to corrosion of the battery terminals and internal components.
* Short Circuit: The water can create a conductive path inside the battery, causing a short circuit and potentially damaging the battery or even starting a fire.
Car batteries require a specific type of electrolyte (usually a mixture of sulfuric acid and water). Adding any other liquid can be very dangerous and is not recommended. If your battery needs to be topped off, use only distilled water, which is specially purified to remove impurities.
Always consult your car's owner's manual for specific instructions on battery maintenance.
