On my phone, if I leave AI Companion running, the battery life of my phone goes down more rapidly.
Consequently, when I am done working on an app on my phone, I go in to Settings | Apps on the Android phone, find MIT App Inventor in the applications list, select it, and then select Force Stop.
I have no idea if other people experience this problem but the fix is simple – just kill the AI Companion app if its no longer needed.
This issues appears to be because the AI Companion links to the App Inventor cloud-based editor – as you edit and make changes, those changes are copied from the editor back to your device, almost in real time. However, if you walk away from the computer and the phone, neither realizes you left for a cup of coffee or to walk the dog – and they may continue to chat with each other, draining the battery.
Regardless, when developing apps for your phone or tablet, your best bet is to turn off battery saving features and leave your phone on (so you don’t have to continually enter your pass code or otherwise restart the phone after it goes to sleep). AND – very important – leave it plugged into a charger. Taking these steps can make your app development go more smoothly.