I suspect this is the reason why two batteries in my P4 stopped working at the same time. By the way, DJI cannot guarantee that the battery will last 6 months as batteries seem to be volatile and always behave unpredictably. Update: After contacting DJI support I can draw some conclusions. 1) DJI is not a company I'm likely to do business with again. There seems to be a lot of issues with the P4's batteries and battery dock storage mode. I was planning to buy Mavic but I won't be dealing with this company anymore. 2) It's ridiculous that these very expensive batteries aren't guaranteed for more than 6 months, especially when they break so easily. 3) I would not use save mode on this device. It's probably best to just take care of it manually and charge the batteries.