All Iris devices contain internal backup battery that enables the device to run uninterruptible in case of the main power supply malfunction.
Battery specifications
- Type: Rechargeable Lithium-ion Polymer Battery
- Capacity: 1800 mAh (6.66 Wh)
- Nominal Voltage: 3.7 V
- Max. Continuous Discharge Current: 2000 mA
- Operating temperature: -20°C ~ +60°C (discharge), 0°C ~ +45°C (charging)
- Expected operational time: 3h
Operation
During normal operation the battery is charged by the device integrated charger. In case of main power supply failure, Iris automatically switches to backup battery. If Iris is detecting airborne conditions, it continues to run on battery until the airborne conditions are no longer detected. In case airborne conditions are not detected, Iris saves necessary data and performs soft shutdown.
There are two types of Iris devices according to detection of airborne conditions:
1. Devices with both static and total pressure sources.
Such devices determine airborne conditions by observing indicated airspeed and climb rate values. To determine the device is NOT airborne IAS has to be below 36 km/h and absolute climb rate below 0.1 m/s for at least 3 seconds. If in any 3 second interval climb rate or airspeed rises above those values, iris will stay in airborne state and will not shutdown.
2. Devices with static pressure source only (altimeter, variometer, etc):
Such devices (standalone) determine airborne conditions by observing climb rate value only. Because in level flight climb rate is kept constant, the interval to detect minor change of 0.1 m/s is extended to 30 seconds. Normally this should be detectable if the aircraft is truly airborne.
IMPORTANT: If static source only device is connected via CAN to other device which provides dynamic pressure data (airspeed indicator, all-in-one), it will act the same as devices with both sources available.
After boot, Iris will not shutdown for at least 20 seconds, then it will start to check conditions above.