It is the winter time right now and my flying days are less then normal.  I am not flying my Air2S through the winter months and I have 8 batteries.  What is the best way to make sure the batteries make it through the winter time and are ready to fly in the spring time?  I don't want to find out that I have 8 dead batteries in the spring.  Where they have swollen, lost their charge completely, or anything else.  I have the majority of them in LiPo bags right nowso if they start on fire I am alright.  I am flying my Phantom 4 Pro over the winter months.  

DJI seems to change from time to time. I don’t need to store any of mine but if I did I’d check every month and see what percentage they’re at. If needed I’d charge to about 60% and check about a month later. Everyone has their way of doing it but the important thing is to not store so long they can’t be changed out of hibernation. I seen other plots which stored them for about 6 months or so without checking them and they could not be charged again. That would be an expensive mistake.. Enjoy.

Hello, there. Thank you for reaching out. You may follow our recommendations regarding battery storage and maintenance to extend battery life and prevent inconvenience.

Battery Storage

1. Discharge the battery to 40-65% if it will NOT be used for 10 days or more. This can greatly extend the battery life.
2. The battery automatically discharges to below 65% when it is idle for more than 10 days to prevent it from swelling. Normally, you may feel moderate heat emitting from the battery during the discharge process. It is recommended to store the battery in a dedicated battery box.
3. The battery will enter hibernation mode if depleted and stored for a long period. Recharge the battery to bring it out of hibernation.
4. Remove batteries from the aircraft when stored for an extended period.
5. DO NOT store the battery for an extended period after fully discharging it. Doing so may over-discharge the battery and cause irreparable battery cell damage.

Battery Maintenance

1. Never over-discharge, as this may lead to battery cell damage.
2. Battery life may be reduced if not used for a long time.
3. Fully charge and discharge the battery at least once every 3 months to maintain battery health.|

I hope the information helps.