
IDP-782 - Hardware Guide
3.8.4 Headset Speaker
Parameter
Min.
Typical
Max.
Units
Speaker Impedance (1 kHz)
14
16
32
Ω
Power Handling Capacity
-
50
-
mW
Operating Frequency
20
-
20000
kHz
3.9 Backup Battery
Terminals with backup batteries are shipped in shelf mode with the backup battery disabled. External
power must be applied to exit shelf mode and begin charging the battery to its maximum capacity. The
terminal continues to operate on external power until the supply voltage drops below the configurable
minimum voltage threshold, at which point it switches over to the backup battery.
The terminal operates on the backup battery, and then perform a graceful shutdown when the battery
reaches its minimum discharge voltage. The battery begins recharging when external power is reapplied
and the external temperature is within the acceptable range. When external power is applied to the
terminal, power is simultaneously applied to the backup battery. To bring the terminal out of shelf mode,
external power needs to be connected to the terminal. Power supplied to the battery (VIN) is protected by a
fuse and load dump within the terminal.
Typically a terminal can be reset by disconnecting and then reconnecting external power. With the backup
battery, cycling external power does not cause a reset because the terminal switches to the backup battery.
There is a small hole on the bottom of the terminal to access the reset button. Insert a paper clip through
the hole to interrupt power and cause the terminal to reset.
Table 6: Internal Backup Battery
Backup Battery
Battery Chemistry
Lithium Ion Polymer
Back-up Period
2.5 hours minimum
Rated Capacity
800 mAh
Charge (capacity) Retention
90% (after 28 days at 25°C)
Nominal Pack Voltage
11.1 V
Minimum Discharge Voltage
9 V
Protection Module Cut-Off Voltage
8.8 V
Charging Voltage / Current
12.65 V / 425 mA
Nominal Output Current
160 mA
Peak Output Current
3000 mA (pulse current 3.0 C5A)
Refer to section 3.1.1 for backup battery temperature ranges.
T213, Version 02
40
© SkyWave Proprietary