Follow these tips to maintain your DJI Spark batteries and ensure they are being properly stored when not in use:
When your batteries are idle (meaning you don't press the battery button), they will start to auto discharge down to the storage level after 10 days. Depending on the current charge level, it could take a battery 2 to 3 additional days to discharge down to the storage level. The batteries will be slightly warm to the touch while they are discharging. Pressing the battery button at any time during this process will cancel the auto discharge process and make your batteries wait 10 more days before attempting to discharge again.
When not using your batteries, maintain the charge level like this:
Keep the current battery charge level within the red box in the image below. When you press the battery button, the 2nd or 3rd battery light should either be solid or blinking.
Don't press the battery button to check the current charge level. On most DJI batteries, pressing the battery button will reset the time to discharge day counter back to zero.
For example, if you press the battery button 9 days after fully charging a battery that you weren't able to use, the battery will wait a total of 19 days before it attempts to discharge itself down to the storage level.
You can find more battery tips in the Spark Battery Safety Guidelines.