Installation Manual

IRIS OEM Edition Hardware Reference Manual
Doc. # 7430-0549-01 Rev. B Page 23
The Table 5-2 below provides some useful guidance on how to predict battery life.
Table 5-2. Estimate of battery life operation for OEM Edition Module
SYSTEM SPECIFICATIONS
Currents
Processor
Example Duty
Cycle
Current (full operation) 6 mA 1
Current sleep 10
μA
99
Radio
Current in receive 16 mA 0.75
Current transmit 17 mA 0.25
Current sleep 1
μA
99
Logger Memory
Write 15 mA 0
Read 4 mA 0
Sleep 2
μA
100
Sensor Board
Current (full operation) 5 mA 1
Current sleep 5
μA
99
Computed mA-hr used each hour
Processo
r
0.0699
Radio 0.1635
Logger Memory 0.0020
Sensor Board 0.0550
Total current (mA-hr) used 0.2904
Computed battery life vs. battery size
Battery Capacity (mA-hr)
Battery Life
(months)
250 1.20
1000 4.78
3000 14.35
; NOTE: In most applications, the processor and radio run for a brief period of time, followed by a
sleep cycle. During sleep, current consumption is in the micro-amps as opposed to milli-amps. This
results in very low-current draw the majority of the time, and short duration spikes while processing,
receiving, and transmitting data. This method extends battery life; however, due to the current surges, it
reduces specified battery capacity. Battery capacity is typically specified by the manufacturer for a
constant nominal current drawn.