Hello,
Thank you for your question.
The device battery consumption depends on few things such as configuration, temperature.
You can find information on our wiki page - https://wiki.teltonika-gps.com/view/FMC125_General_description
For example FMC125 has a 3.7 V 170 mAh rechargeable Li-ion battery;
And these are the average consumptions -
GPRS: average 64.59 mA
Nominal: average 37.77 mA
GNSS sleep: average 11.1 mA
Deep Sleep: average 6.2 mA
Online Deep Sleep: average 6.5 mA
So you can calculate how long will it last in different modes -
170mAh (battery capacity) / 64.59mA (GPRS: average) = 2 - 3h
170mAh (battery capacity) / 6.2mA (Online Deep Sleep consumption) = ~27h
And so on.
Hope this will be useful for you.
Best regards.