SensorPush BLE sensor battery reading, again

I have a SensorPush outdoor temperature/pressure/humidity sensor that I&rsquo;m pretty happy with. It&rsquo;s BLE, it&rsquo;s reliable, its range is good, it seems pretty accurate. However it doesn&rsquo;t report its battery level in its adverts, but the manufacturer app can read this level through reading GATT characteristics. I previously had a go at adding this to my HA two years ago. It worked…