Power budget is getting tighter in modern gliders. Power for sound can be one of the highest consumers of power from the battery.
The VRM10 has high efficiency sound minimizing power drain, extending battery life.

Battery monitoring and alarm with LCD screen sign and clear voice "low battery" message.
The Variometer itself will continue to operate at full specification below 7 volts supply.

Power security with redundancy from the PK312 Battery backup which mounts a 9V battery and has automatic change over if main power fails. Great to know you can have audio to get home or to allow a flight to continue in the event of power loss.

12 hours or more operation is available with a fresh battery from PK312. Check Documents section for more details.

Automatic power down.
The VRM10/VD110 Variometers sre able to detect if it has been flying and self powers down if inactive.
This smart power down is included to prevent discharge of the PK312 Battery backup after main power shut down on the ground.