Recently completed a mission, the P4M returned, landed and shut down  normally. The controller was then completely unresponsive. It would not  shut down and none of the controls had any effect. After some hours it  was quite warm over the "statr" button and I allowed it to fully  discharge the battery. When placed on charge again it appears to  function normally. This seems to be a software lock-up which is  corrected when the CPU reboots. As the battery is not  easily accessible is there some way of rebooting other than removing the  power?

If you are in the field, as I was at the time, the whole program had to be aborted until the battery was flat, about 14 hours.

I if necessary I will fit a battery cut off switch so this does not happen again! It's not good for business.

An addition to the previous post - the LH indicator was showing "red" and the battery indicator llights showed 'full'. I could not switch off and on again to try reconnecting with the P4M so don't know if that would have hel;ped.