The following information applies to all SeaLife products using rechargeable Li-ion batteries.
We recommend using the XTAR brand 18650 Li-ion batteries (2600 or 3400mAh), which are premium-grade batteries using Panasonic/Sanyo or Samsung cells produced in Japan. These two XTAR batteries are capable of delivery 5.2A discharge current, suitable for high-powered devices.
If you do use another brand 18650 battery, make sure it meets all of the following requirements:
1) Button cell top
2) Integrated protected circuitry
3) Minimum mAh rating of 2600
4) Minimum discharge current of 3.5A
5) Cell made in Japan by reputable brand like Panasonic/Sanyo or Samsung
Warning: Never use a damaged 18650 battery! Replace the battery if its sleeve/wrapper is cut, torn damaged in any way. The external sleeve helps to prevent short circuiting the battery. Short circuiting occurs if a metal objects makes contact with the + and – end of the battery at the same time, which will result in the battery overheating and may result in fire or explosion.
Li-ion rechargeable batteries, as well as all other types of batteries, will perform best at approximately 80°F (27°C). As temperature drops, so will the battery life. While Li-ion batteries can operate at sub-freezing temperatures, their run time will significantly drop to about 50% at extreme cold temperatures of -20°F (-29°C). When using Li-ion batteries in extreme cold, try to keep the batteries as warm as possible to extend battery life. It is also a good idea to have some fully-charged spare batteries on hand so you can quickly exchange batteries when needed.
Note: Make sure to check the operational temperature limits specified for the UW light or camera that you are using. Most underwater lights and cameras include minimum and maximum operating temperature.
When storing Li-ion rechargeable batteries for more a few months or more, battery should be charged to about 50%. Batteries should be stored in a dry environment at room temperature (approximately 70°F/21°C to 80°F/27°C). This will help to maintain the battery’s life and performance.