Hi Kajuma,
Thank you for reaching out to the Teltonika Telematics Community forum!
To avoid draining your vehicle battery you can enable the sleep modes
To know more please click here: FMB920 System settings - Wiki Knowledge Base | Teltonika GPS (teltonika-gps.com)
You can also set the data acquisition according to the modes: FMB920 Data acquisition settings - Wiki Knowledge Base | Teltonika GPS (teltonika-gps.com)
Best Regards,
Maynard C.