Finally got around to replacing the old corroded soldered-in D cell in the RCA Voltohmyst with a new battery today.
Snipped the wires off the battery and into the trash it went. Had to drill out a rivet to remove the battery holder clip.
The battery holder is a little on the big side and just fits into the space vacated by the old battery and clip. Soldered the wires onto the battery holder and fastened it to the Voltohmyst using some double sided tape.
Now it’s got a new battery that can be replaced whenever it’s needed.
Next thing to do is go through the manual and read up on how to calibrate the meter.