FJ system Lithium Polymer Batteries are rated for a lifespan of 300 + charge cycles.
You can help maximize and increase that life by charging an FJ battery before it is empty.
Lithium Polymers do not have a memory. Therefore you should never deplete them totally as with other powering options such as NiCad Batteries. Westcott's FJ system has built in protection to prevent total discharge when in use. If stored long term the remaining protective charge can dissipate.
Recharging the FJ battery before the battery is 75% depleted can prolong the battery life.
Avoid charging when the battery is below 10ºC/50ºF. The chemistry in the battery is less efficient below that level.
Hot Lithium Polymer batteries don’t take a charge well and continued overheating of your FJ units will reduce the life and functionality (frames per charge) of the battery. Allow the batteries to cool after use before charging. If your FJ400 unit nears or reaches OH (overheating) status, let the FJ400 fan help cool the battery for 30 to 40 minutes before powering off the unit and placing it on the charger.
Lithium Polymer batteries should not be stored long term with a full charge. Chemistry in the batteries can expand when stored for an extended period and may render them unusable.
A storage level between 50% and 75% is suggested as Lithium Polymer batteries lose less than 1% of their charge per month when stored. Therefore, there is little chance they will discharge too far unless stored for a very long time.
Do not store the batteries with an extremely low charge as Lithium Polymers do not react well to a complete discharge.
Significant discharges not only shorten the lifespan but done continually can also damage the battery. Regularly maintaining charge levels above 25% will enhance the lifespan of your battery. Follow the directions for charging that comes with your FJ product manual.