Power consumption problem

[Saram]

I have a custom board with nrf52840 with cr2477 battery (1Ah capacity). I was download firmware to board and after a week the battery voltage dropped to critical. In the firmware forcibly turned on dcdc and in power_manage added:
sd_power_mode_set(NRF_POWER_MODE_LOWPWR);
But problem is still here. 

What other critical places are there that you need to pay attention to?

[Saram]

stayed the same. for 1 hour of work (300 ms between transfers, eddystone uid) - 0.2 volt voltage drop (on a fresh battery)

[bjorn-spockeli]

OK, so you're only measuring the voltage of the battery, not the current consumption? Could you upload the entire project folder to the case? I would like to run the code on a nRF52840 DK. 

Best regards

Bjørn