I have had my DSO Quad for several days now and really like it.
My battery appeared dead yesterday after I adjusted the trimmer capacitors. I removed the back cover and reseated the connector from the battery and it came back to life Vbt=+4.02V.
A tiny bit more room inside the battery case would be nice in the future. The cover fits so tightly that it is easy to disturb the battery connection.
-Dick