Xylem CHATTER RTU and E-mail - Manual (Page 162)

USERS MANUAL
CHATTER™ DATA LOGGER
162
Battery life expectancy
Calculating the battery life is complicated, a lot of different factors are involved. The battery has an initial capacity
of 19 Ah or 19.000 mAh. To make allowance for ageing, environment and variations between batteries, the
capacity used for calculating battery life expectancy is set to 17 Ah or 17.000 mAh. Below is a table showing the
'cost' of different operations.
Operation Cost
Send an alarm to a SCADA system or as a SMS message 5 mAh
Make one log, send data to a SCADA system or as a SMS message 5 mAh
Make four logs, send data to a SCADA system or as a SMS message 6 mAh
Make one level measurement, save data in the log, 10 seconds measurement delay 0,15 mAh
Make one level measurement, save data in the log, one seconds measurement delay 0,1 mAh
Make four level measurements, save data in the log, 10 seconds measurement delay 0,3 mAh
Make four level measurements, save data in the log, one seconds measurement delay 0,2 mAh
Make one measurement without saving data in the log - event logging 0,02 mAh
An example:
Operation Measurement Transmitting
A Chatter™ Data Logger measures a level with
a 10 seconds measurement delay and saves the
result in the log once every hour. It connects to
a SCADA system once every 12 hours: Measurement and logging of data:
24 × 0,15 mAh = 3,6 mAh
Transmitting data to a SCADA
system:
2 × 5 mAh = 10 mAh
This totals 13,6 mAh every day.
Life expectancy is thus 17.000 mAh / 13,6 mAh = 1.250 days or a little less than 3½ years
An other example:
Operation Measurement Transmitting
A Chatter™ Data Logger measures a level with
a one seconds measurement delay and saves
the result in the log once every 24 hours. It
connects to a SCADA system once every 24
hours: Measurement and logging of data:
1 × 0,1 mAh = 0,1 mAh
Transmitting data to a SCADA
system:
1 × 5 mAh = 5 mAh
This totals 5,1 mAh every day.
Life expectancy is thus 17.000 mAh / 5,1 mAh = 3.333 days or a little more than 9 years