this is embarrasing

i was trying to locate the battery and no wonder i was having a difficult time removing it - it was not the "battery" it was a round white plastic thing that i managed to pop the top off. inside was a round metal thing - i think it was the buzzer

anyway, i found and replaced the real battery (CR1220 - thanks to mr. rough512 ) the charger now retains the settings every time i power up.

another question (please bear with me )
- do i need to recalibrate the charger? since i got mine used, it may have been a while since the battery power was gone. now that it has a new battery, do i need to do reset the unit or do something? ive been told that the charger comes with both a manual and a separate sheet with parameters. i have the manual but i dont have the other sheet.

again, thanks in advance for any info