Is it possible the device is not generating a battery report event? A lot of devices only generate an event if the value changes. Have a look ate the live logging in the IDE. you should see lines like these appear. each time the smartapp runs and doesn’t not find an event to log.
759bf2fc-1e34-4b58-ab2c-6c340998d718 20:48:24: debug SmartThings found 0 events between 10/11/2020 20:43:25 and 10/11/2020 20:48:23
759bf2fc-1e34-4b58-ab2c-6c340998d718 20:43:24: debug SmartThings found 0 events between 10/11/2020 20:38:25 and 10/11/2020 20:43:24
759bf2fc-1e34-4b58-ab2c-6c340998d718 20:38:25: debug SmartThings found 0 events between 10/11/2020 20:33:24 and 10/11/2020 20:38:24
Here is a section where events were generated and logged
759bf2fc-1e34-4b58-ab2c-6c340998d718 11:03:48: debug SmartThings found 0 events between 11/11/2020 10:58:26 and 11/11/2020 11:03:47
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:58:28: debug Google Sheets Web App logged 1 events between 11/11/2020 10:53:23 and 11/11/2020 10:58:25 in 2.485 seconds.
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:58:26: debug SmartThings found 1 events between 11/11/2020 10:53:24 and 11/11/2020 10:58:25, posting them to Google Sheets Web App
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:53:27: debug Google Sheets Web App logged 1 events between 11/11/2020 10:48:23 and 11/11/2020 10:53:23 in 3.746 seconds.
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:53:23: debug SmartThings found 1 events between 11/11/2020 10:48:24 and 11/11/2020 10:53:23, posting them to Google Sheets Web App
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:48:26: debug Google Sheets Web App logged 1 events between 11/11/2020 10:43:23 and 11/11/2020 10:48:23 in 2.732 seconds.
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:48:23: debug SmartThings found 1 events between 11/11/2020 10:43:24 and 11/11/2020 10:48:23, posting them to Google Sheets Web App
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:43:23: debug SmartThings found 0 events between 11/11/2020 10:38:24 and 11/11/2020 10:43:23
759bf2fc-1e34-4b58-ab2c-6c340998d718 10:38:24: debug SmartThings found 0 events between 11/11/2020 10:33:24 and 11/11/2020 10:38:23
BTW, I am logging a temperature sensor at the bottom of my fishpond.