Hi from Greece everyone! Since I don't know what is the best for my battery health please let me know...I already have 32 flights with my Phantom 4 Pro and after my last flight the current battery status is 7%. It's ok to leave it like that for storage until my next flight or I should charge it about 40% - 50%? I think that we should recalibrate our batteries after 20 flights. On the other hand I don't have any issues with my battery. Thank you in advance for your time! Take care and keep flying!

I like to keep mine a hair above 50% and I like to check it often.  If it was in "storage", I would check it every few weeks.  I don't like it to drop below 50% unless it's in the air.  

There is no need to calibrate your batteries.
Storage at a low level is bad for the battery.
Ideal storage level is around 50%.

Thanks both of you for taking the time to answer me. I'm going to charge the battery since the first two leds stay green.Take care and keep flying!

is there any way to bring a battery back???  stored 100% charged but left it for a year and now no lights turn on at all.   New battery only used 3 or 4 times.  Is there any way to bring it back???

I guess other users have given you the answers. Please charge/discharge the battery to 40%-65% if it will not be used for 10 days and more to extend the battery life.
Please check more details about how to maintain battery here: https://dl.djicdn.com/downloads/ ... y+Guidelines+En.pdf

Gilan Posted at 2017-11-12 18:12
is there any way to bring a battery back???  stored 100% charged but left it for a year and now no lights turn on at all.   New battery only used 3 or 4 times.  Is there any way to bring it back???

I'm afraid the battery was over-discharged, the battery must be fully charged and discharged once every 3 months to maintain the health.
You can try to charge the battery over 1 hour to see if there is any response, otherwise, the battery cannot be used anymore.