have twice had the big clip on back come apart.  first time, hit wooden floor, secomd time landed on concrete, and battery flew off-
call me clumsy.  also dropped (accidently!)  several other times!  on the second drop-the spring, and clip landed in some grass, but was able to find them.
this is one rugged little beast!
 
this on a uv5r but believe clip same on most models
 
ANYWAY---after second explosion-got out the jb weld (epoxy)-put a dab on each end of the pin going thru the spring, and a dab on the spring in the rear.  NO MORE SEPARATION PROBLEMS.
 
presently firing up 6 uv5re plus units-they have all been epoxied!  love this little beastie!
 
word to the wise.  get out the epoxy now!
 
73   jim  kf8sj