I recently bought a new battery for my P2V+, and as a result had to upgrade all my firmware to the latest versions (main controller 3.14). Unfortunately this upgrade has made my original battery (still good, bought with the drone in Dec 2014) unuseable - as soon as I take off the rear LED flight indicators flash red, and I get a critical low battery indication causing the drone to descend on its own immediately. When I view the battery firmware version with the V3.8 Assistant Software, I see that the new battery is v188.8.131.52 (loader 184.108.40.206) while the old battery is v220.127.116.11 (loader 18.104.22.168). I suspect my old battery has an out-of-date firmware that needs to be upgraded to the latest version, however when I try to upgrade the battery using the V3.8 Assistant Software, it says there are no new upgrades. All other firmware versions are identical when I view the drone with each battery. Can anyone help with advice or a fix for this problem.