New user here and have a question. I am thinking of picking up the USB power bank adapter but am concerned about using it.

Many folks say that it is best to never completely discharge your battery and was wondering if there is some failsafe in the battery or adapter that prevents that.

I generally end all flights with roughly 30% battery left and was thinking about using this is a means to charge my phone between shoots with the used battery.

Thoughts appreciated.

You cannot over-discharge the DJI batteries in normal use, they will switch off before that happens. DJI even recommends to completely discharge them once every three months and then fully recharge them in order to maintain maximum capacity and lifespan. You should just not store them fully discharged.

Thank you for the reply. This is reassuring to know.

I would put that 20 dollars towards a dedicated usb battery pack.