Assessing A typical System For Battery Life
Use a table similar to the one indicated below to make an assessment of the system power
requirement.
System Component
Alarm Mode Current Quantity
Totals
Tocsin 700
0.25Amps
1
0.25Amps
Tocsin 920
0.5Amps
NA
NA
Tocsin 102 Pellistor HC Detector
0.13Amps
0
0
Tocsin 102 Toxic Gas Detector
0.02Amps
5
0.1Amps
Audible Alarm (Typical Example)**
0.12A
0
0
Additional Relay Units (8 Per Card)* 0.01A/Relay
0
0
Visual Alarm (Typical Example)**
0.15A
1
0.15Amps
Tocsin 102 IR HC Detector
0.05Amps
4
0.2Amps
Total System Current 0.7 Amps
The batteries used are 1.2AH units so using the previously indicated de-rating factors the
expected battery life will be as follows:-
Expected Operating Battery Life= Battery Capacity x de-Rating Factor
Total System Current
= 1.2AH x 0.75 = 1.3 Hours
0.7A
Values indicated in the system component table are those for alarm condition to take account of
the greatest possible current draw.
Note that in this example whilst the de-rating factor indicated was just 10% of battery capacity the
next de-rating factor up was chosen.
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