One the Console, try holding the TEMP an the HUM buttons down at the same time (make sure the buttons are in the 'normal', not secondary mode
*). The bottom line will display several important items:
"
BGN nn" (The Background noise level, the lower the number the better)
"
BATTERY nnnV" This is the... wait for it... Console battery voltage!
I've not tried seeing what the "BATTERY" numbers might be
without batteries installed. However, the Davis Manual states, "
Ignore this value if using the AC Adapter only to power the console."[
Vantage Pro2? Console Manual (Rev k), item 14, page 38]
The traditional voltage meter method works well, of course. I
did need to use a modified (straightened) paper clip to reach the center/inner contact on the power plug.
*Each pressing of the LAMPS/2nd button changes the function of each button between the label on the button and the label on the Console body.