Lithium batteries have revolutionized scuba diving by powering a wide range of devices, from dive computers and underwater lights to cameras and scooters. Their high energy density and long life span make them ideal for marine environments. However, lithium batteries also pose unique hazards. Understanding how to properly handle, store, transport and charge these batteries is essential for diver safety and equipment longevity.

Potential Dangers of Lithium Batteries

While lithium batteries are generally safe when used correctly, they can become hazardous if damaged or handled improperly. The primary risk is a runaway reaction or short-circuit that generates intense heat, potentially leading to fire and releasing toxic fumes. In the confined spaces of an airplane or dive boat, a lithium battery fire can be catastrophic. Additionally, water intrusion into battery casings can lead to corrosion, leakage and electrical failure.

Related Reading: Life as a Dive Computer Engineer and Test Diver

Proper Storage, Transportation and Handling

Battery safety begins with choosing high-quality batteries from reputable manufacturers. Always inspect batteries for swelling, discoloration or damage before each use as these may be signs of compromise. If any issues are detected, the battery should be recycled at designated locations.

Because of their fire risk, transporting lithium batteries—especially by air—is strictly regulated. Most airlines require that lithium batteries be carried in carry-on luggage and easily accessible. Batteries over 100 watt-hours require airline approval, and no single battery may exceed 160 watt-hours for passenger aircraft. Check with your airline and local regulations as rules may vary.

When not in use, store lithium batteries in a cool, dry and well-ventilated location, away from direct sunlight and heat sources. Best practices include keeping batteries at about 50 percent charge if stored long-term and never storing them fully charged or completely drained, as both extremes can reduce lifespan and increase instability.

I like to store all my batteries with terminal covers or in designated boxes to prevent short circuits. When transporting batteries, a drop-and water-resistant container such as a Pelican case can ensure you avoid damage.

Best Practices for Charging Lithium Batteries

Charging is one of the riskiest activities involving lithium batteries. To minimize hazards:

» Use Manufacturer-Approved Chargers

Only use chargers designed for your specific battery and voltage (which vary across the globe). Mismatched chargers can cause overcharging or short-circuits.

» Charge in a Fire-Safe Area

Never charge batteries near flammable materials. Choose a fireproof surface, such as ceramic tile or metal. Liveaboards in particular often have specific rules on where and how many devices can be charged at the same time to prevent overloading the vessel’s circuits.

» Monitor Temperature

Batteries should never be charged without direct supervision. Batteries that become excessively hot during charging may fail. Immediately disconnect them and move them to a safe location.

» Invest in a Battery Charging Safety Bag or Box 

Fire-resistant charging boxes/bags can mitigate flame and smoke if a battery does catch fire. However, these products should not be used as a substitute for direct observation.

Lithium batteries are indispensable tools in modern scuba diving, offering compact power for critical equipment. By understanding the risks and adhering to best practices in handling, storage, transportation and charging, divers can safely harness the power of this technology. Whether you’re heading out for a recreational dive or a technical expedition, battery safety should always be part of your dive plan.