5 Electrical Assemblies
5.1.2 Extending Battery Life
The CNI4 is designed to provide a long service life when operating from batteries. Total battery life is
influenced by two factors in the CNI4 — continuous background current and high current draw during
cellular calls. The background current can be minimized to a certain extent by using fewer pulse input
connections and using normally-open (Form-A) contacts for pulse and alarm sensing. High current draw
depends on the number and duration of cellular calls made. This can be minimized by ensuring the CNI4
has strong cellular reception (which minimizes call retries) and by limiting the number of regular
scheduled calls to a practical extent.
The battery life also depends on bluetooth advertisement interval and so it is recommended to optimize
the usage of bluetooth.
5.2 External Power Option
A 3 Pin connector is available on the Y-cable to connect to an external power supply. Where AC power is
readily available, as is the case at some sites, use a power adaptor to supply the necessary voltage. The
power adaptor is required to be capable of sourcing Class 2 power supply with 2A rated current, 5V to 16V
To setup external power supply
1. Remove the housing of the metal conduit and route the power cable through it.
2. Connect the power cable to the 3-Pin power connector on the Pulse Accumulator Board.
3. Connect the other end of the power cable to an external power source (5 to 16 V, 2A peak current).
The output voltage from the power adaptor can be wired to the positive and GND terminals of the 3 pin
connector shown above. It may be necessary to check with a voltmeter to determine the positive and GND
wires coming from the power adaptor. Polarity of the terminal block connection will be apparent from the
wire color — Red is positive and Black is negative.
In the event of a reverse connection, no harm will be caused to the electronics but the CNI4
will not power as expected.