RE: nrf9160 disposable battery

FZe — Mon, 11 Apr 2022 06:00:44 GMT

I did measure the batterys using a cheap usb oscilloscope, they drop when loaded but only about 150mV. I will test to increse the bulk caps

The ADP2503 seems nice but still draws to much current for my application ( 38uA from datasheet )

Have you made any real life measurements on ADP2503 current consumtion ?

Regards

RE: nrf9160 disposable battery

Craig12 — Mon, 11 Apr 2022 00:56:50 GMT

It sounds like your Alkaline batteries have too high internal resistance and the output voltage drops when the radio starts talking. One option would be to add some bulk capacitance, but as you have observed there is a specification indicating to meet 3GPP RF compliance the minimum voltage is 3.3V.

We have been using an ADP2503 600mA, 2.5MHz Buck-Boost DC to DC converter with our nRF9160's. It will accept an input voltage from 2.3 to 5.5V. The only downside we have is it doesn't have a programmable low voltage lockout (i.e 2.5V for Li-Ion), but for disposable primary cells you probably don't care - and want to run them until they are practically dead.