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6 Battery operation and power saving mode
PLICSMOBILE • Mobile network unit PLICSMOBILE T81
55234-EN-191217
The solar cable combines PLICSMOBILE B81 with the solar panel
PLICSMOBILE S81. It is available in the lengths 5/10/25 m. Connect
the cable as shown in the wiring plan.
Caution:
Make sure that the two cores of the connection cable are energized
when the solar module is already connected and not covered. Avoid
a short circuit during mounting and connection. Also pay attention to
this when shortening the cable, if that should be necessary.
6.4 Battery - Sizing and operating time
When selecting an external battery/accumulator, the following points
must be observed:
Power consumption in power saving mode:
If you use a battery or accumulator that cannot be automatically
recharged cyclically, the power saving mode should be activated.
With an operating voltage of e.g. 12 V, a standby power consumption
of 0.4 mW must be taken into account. With an assumed lifetime of
e.g. one year, the requirement is approximately 3.5 Wh, which cor-
responds to a battery capacity of 0.29 Ah at 12 V. The standby power
consumption at specific operating voltages is stated in the "
Technical
data
".
Power requirement for a complete measurement cycle incl.
measured value transmission:
A measurement cycle lasts approximately 60 to 120 seconds (de-
pendent on sensor type and network quality) and includes automatic
switching on of the sensor (HART multidrop mode with 4 mA), record-
ing of the measured value, measured value transmission and a return
to the power saving mode. During this time, approximately 15 mWh of
energy is required. For example, with one measurement per day, this
adds up to approx. 7.3 Wh per year, which corresponds to a battery
capacity of approx. 0.6 Ah at 12 V.
Examples for battery capacity depending on the number of
transmission cycles
Quantity
Messages/Days
Annual consumption PLICSMOBILE
Standby energy
demand
Energy demand
for message
transmission
Required battery
capacitance with
12 V
1
3.5 Wh
7.3 Wh
0.6 Ah
2
3.5 Wh
14.6 Wh
1.5 Ah
4
3.5 Wh
29.2 Wh
2.7 Ah
8
3.5 Wh
58.4 Wh
5.1 Ah
24
3.5 Wh
175.2 Wh
14.9 Ah
Tab. 1: The specifications refer to the connection of a sensor
Connection
