The screen displays V1 briefly, then shows a numeric value with the first digit flashing. Tap the to increment the flashing digit (0–9).

Use the button to alter the flashing digit value and the SWI button to advance to the next digit.

Normally Open terminal (connects to COM when relay is active).

Are you planning to use the DVB01 for a or a DIY battery charger ?

The DVB01 manual typically opens with a standard “Safety and Package Contents” section. According to most versions:

): Relay stays active ("On") only when the voltage is outside the set limits (either higher than the upper or lower than the lower limit).