I have a MZ-RH1 that will run when used with the charger, but not with the battery alone. A new battery was purchased from China, but that did not work.
It works perfectly, record and playback, when hooked up to the charger, and both batteries show > 3.7 V on my VOM, so they should
be charged, but I can't get it to work on just battery power alone. Could be I'm doing something stupid, but I can't figure out what.