I can try to disconnect and reconnect the battery today at work -- I brought a small screwdriver, etc.
I don't have a replacement battery. I suppose I could try to figure out whether one might be available locally. I'd rather not wait for a replacement battery from Germany if 1) I can get one here and/or 2) the device's symptoms don't indicate a battery change would help.
Like everything else on-screen, the battery charge indicator is frozen. In its case, it is in a sort of greyed-out state.