I program embedded circuits, often using a multi-meter to verify functionality. Almost every multi-meter has an frustrating "beep after X minutes" when it's on. It's become a pet peeve! Are there any solar powered voltmeters out there? I want it to just always have power.I know solar panels + indoor lighting don't work too well together. A second best would be one with a nice lithium rechargeable and adjustable "shut off period".