Batteries & Charges

Frequently asked questions

How long does it take to charge a dive light battery and how do I know when it is fully charged?

Charge time varies significantly between dive light models and battery capacities — typically ranging from 2 to 8 hours for a full charge from depleted. Most rechargeable dive lights include a charge indicator: an LED that turns red or blinks while charging and turns green or solid when fully charged. Some lights charge via USB and can use a standard USB power bank for field charging on boats or remote locations without mains power. Always allow a full charge cycle before your first dive of a trip — a partially charged light may have insufficient burn time for a longer night dive. Charge the night before, not in the morning rush before departure.

Can I use third-party replacement batteries in my Big Blue dive light?

We recommend using the manufacturer-specified battery or charger for your specific light model to ensure correct voltage, capacity, and charging profile compatibility. Third-party lithium battery packs with slightly different voltage or discharge characteristics can affect light output, burn time, and in some cases may not trigger the low-battery warning correctly — leaving you with an unexpectedly dim or dead light mid-dive. Where we carry Big Blue-specific replacement batteries, these have been matched to the correct specifications for the light model. Contact us with your light's model number and we can confirm which battery option is correct for your specific unit.

How should I store my dive light batteries when not in use for extended periods?

Lithium-ion rechargeable batteries store best at approximately 40 to 60 percent charge — not fully charged and not fully depleted. Storing a lithium battery at 100 percent charge for months degrades the chemistry faster than storage at partial charge. Storing a battery at zero charge for extended periods can cause permanent capacity loss or cell damage. If you are putting your dive lights away for the off-season, charge them to approximately half capacity, remove them from the light (if removable), and store in a cool, dry location away from extreme temperatures. Check and top up the charge every few months during extended storage. Before the first dive of a new season, perform a full charge cycle and check that the light operates correctly before relying on it in open water.