Respironics BiPAP Focus Operator's Manual page 51

Operation
full charge cycle should be run. A fully charged battery will deplete within
3 months if unused and not charged. This is the normal depletion rate
when the unit is stored with the ON/OFF switch in the OFF (O) position. If
the unit is left in Standby mode with the ON/OFF switch in the ON ( | )
position and it is not connected to AC mains power, the internal battery
will deplete within 2 weeks.
CAUTION: To prevent the premature depletion and reduced life
expectancy of the battery, store the ventilator with AC power
connected and the ON/OFF switch in the ON (I) position. When the
ventilator is stored disconnected from AC power with the power
ON/OFF switch ON (I) and in standby, the battery may become
depleted within two weeks. When the ventilator is stored with the
ON/OFF switch in the OFF (O) position, the battery typically
becomes depleted in three months.
If a 343 error code is displayed, contact Service. The battery needs
replacement.
CAUTION: During battery charging, disconnecting AC mains power
before charging completes may result in a Battery Depleted
message. Connect AC power immediately if Battery Depleted alarm
annunciates to avoid total loss of power.
NOTE: For maximum battery performance, a new battery or a battery that
has been in storage should be fully charged and discharged two to three
times.
®
BiPAP Focus™ Noninvasive Ventilator System 45
1027404 Rev K