Can a flooded battery still be used?
2 Answers
If a car battery is submerged in water and not treated promptly, it cannot be used. Although the battery contains water, it is different from ordinary water. The water inside the battery is usually distilled or high-purity water with very low conductivity, making it essentially non-conductive. However, the water commonly found in daily life contains various metals and trace elements, which can conduct electricity, leading to short circuits and other issues in the battery. What to do if the car battery is drained: A drained car battery can cause sulfation. Severe discharge may even render the battery unusable. Battery discharge, or deep discharge, occurs when the voltage drops below 10.50V, causing sulfuric acid and lead plates to form lead sulfate. If not charged promptly, the lead sulfate will crystallize. Over time, these crystals will not decompose even when recharged, a phenomenon known as battery sulfation. If the car battery is drained, it should be charged immediately using a battery charger. If a regular charger fails to charge the battery, a repair device with high-resistance repair must be used to raise the voltage above 10V before charging can proceed.
I've also experienced a flooded battery before. That time, during heavy rain, my car got submerged, and the battery was soaked in water. When I opened it up, I found it short-circuited inside, with the electrodes corroded and blackened. A waterlogged battery is basically unusable directly because the internal electrolyte may be diluted, leading to risks of leakage or explosion. Especially for common types like lead-acid batteries, flooding can cause uncontrolled chemical reactions inside the battery, resulting in unstable voltage and sudden stalling while driving. My advice is, don't risk starting the car; immediately disconnect the battery terminals and take it to a professional shop to check the capacitance and terminals. If the electrolyte is cloudy or the electrodes are severely damaged, you'll have to replace it with a new one. Usually, parking on higher ground can prevent flooding, and timely handling of issues is safer.
