
EK280
Application Manual
161
10.5
Data transfer duration in modem battery operation
10.5.1
Data transfer duration depending on ambient temperature
In battery operation the modem battery power is reduced during data transfer. At a low ambient temperature
it is reduced more quickly than at a high ambient temperature.
If the data transfer takes too long, the battery voltage falls below its minimum 3.2V and the data transfer is
terminated.
The following table gives maximum data transmission duration values at intervals of a week or more at different
ambient temperatures. For daily data transfer chapter 10.5.2 applies.
Ambient
temperature
Maximum
Data transfer
-10 °C
15 minutes
0 °C
20 minutes
+10 °C
30 minutes
+25 °C
45 minutes
+50 °C
80 minutes
10.5.2
Data transfer duration for daily call
As explained in chapter 10.5.1 the battery voltage is reduced during data transfer and reduced more quickly
in low ambient temperatures than higher.
After data transfer the voltage rises again more slowly in low ambient temperatures than in higher.
If the data transfer regularly begins before the battery voltage has returned to its starting value, the voltage is
always lower in the long term. As a result of this the data transfer may at some point be terminated due to low
battery voltage, or may even fail to start.
This effect must be considered in particular for daily data transfer and lower ambient temperatures. This can
be avoided by reducing the amount of data to be transmitted daily so that the maximum data transfer duration
given in the table below is not exceeded.
With data transfer cycles of a week or more, even at low temperatures the modem battery has adequate time
to recover between transfers.
The following table gives guidelines for the maximum daily data transmission duration at low ambient
temperatures. In temperatures from +20 °C upwards chapter 10.5.1 applies even for daily transfers.
Ambient
Temperature
Maximum daily
Data transfer
-10 °C
3 minutes
0 °C
5 minutes
+10 °C
8 minutes
+25 °C
45 minutes
as per chapter 10.5.1
+50 °C
80 minutes
as per chapter 10.5.1