[Pro2006] 2006 Internal Battery?

[Mike]

One of my 2006's has a continual beep about a second apart.  I am assuming
there is an internal battery of some kind besides the 9v backup battery?  I
have changed the 9v battery and the scanner continues to beep.  I'm sorry if
this has been discussed many times before.  The operation manual does not
mention an internal battery other than the 9v.  Any info on this?