From the Moderator on DJI Fourm "Thanks for reaching out! It is suggested to test your 2 other batteries now so you can confirm whether they're working properly. After you have tested and confirmed that they're working, it is best to store them temporarily until you resume flying. Before storage, it is recommended to charge the battery to approximately 72%. It is recommended to charge and discharge the battery once every three months to improve battery performance. If the battery level is below 72%, it is recommended to charge it until it is 72% before storing. If the battery level is above 72%, the battery will discharge automatically after 5 days to 72%"