battery warranty is not voided in circumstances complete depletion. just yesterday afternoon drone remained energized cabling usb mp4 files out from it. it took too long. i did not know whether mp4 loss would result on forced "move" cancellation. so i let battery shut itself off from complete depletion during usb cabled mp4 offloading.I think DJI does the same thing with its batteries. But I don't have the guts to run down my battery to 0 percent and find out.
the battery immediately was charged by line powered charger provided and succeeded charge up satisfactorily.
too bad there's no battery analyzer which actually calculates impaired performance if any based upon known performance expectation.
turns out the mp4 "move" command aborted the involved mp4 movement. fortunately the movements of the earlier mp4 files were successful.
upon resumption of moving mp4's, swapped the usb cable to three inch in lieu threefeet. discovered tenfold faster per file moved!