Many people started to have issues within 30 charges.
I have seen many posts in phantompilots.com, and apparently it linked to two possible root causes. They are
a. Recent firmware, especially on and after 3.06. DJI knows about it hence it updates and updates related to the batteries. DJI tried to hide something...
b. Battery quality issue. Whenever pilots got problem, they sent to shops and DJI accepts and replace for you!!! Which means there are some hidden problem that users not known!!!