What happens when a lithium battery gets wet?

Lithium batteries power our daily lives—from phones and laptops to electric cars and power tools. They’re lightweight, long-lasting, and efficient. But there’s one thing they don’t handle well: water.

Whether it’s a spilled drink, rain, or high humidity, water can seriously damage lithium batteries—or even make them dangerous. Here’s what happens when lithium batteries get wet, how to prevent it, and what to do if an accident occurs.

Lithium-ion (Li-ion) and lithium polymer (LiPo) batteries are not waterproof. Water can cause big problems:

1. Short Circuits

• Water conducts electricity. If it gets inside the battery, it can create a short circuit between the terminals.
• This can lead to overheating, swelling, or even fires in extreme cases.

2. Corrosion

• Water can rust the battery’s metal parts, damaging its internal structure.
• Corrosion reduces performance and can make the battery fail prematurely.

3. Electrolyte Leaks

• The liquid inside lithium batteries (electrolyte) is highly reactive.
• If water breaks the battery’s seal, the electrolyte can leak out, posing a chemical hazard.

How to Keep Lithium Batteries Dry

Since water and lithium batteries don’t mix, here’s how to protect them:

Use Waterproof Cases

If you’re using batteries outdoors (e.g., in boats, RVs, or solar setups), put them in a sealed, waterproof box.

Check Seals & Compartments

• Make sure battery compartments in devices (like power tools or e-bikes) are properly sealed.
• Replace worn-out gaskets or covers.

Avoid High Humidity

• Don’t store batteries in damp places (like basements or bathrooms).
• If needed, add silica gel packs to absorb moisture.

Never Submerge Them

• Even “water-resistant” devices (like some flashlights) aren’t designed for full submersion.
• Keep batteries away from pools, sinks, and heavy rain.