Before releasing production versions, we test the app on these phones: Google Pixel 3a, Android 10 Huawei P8 Lite, Android 6 Huawei P20 Pro, Android 10 OnePlus 7T, Android 10 Samsung Galaxy S6, Android 7 Xiaomi Pocophone F1, Android 9 iPhone 12 iPhone 6s Google Pixel is generally considered standard in Android development. If it works on a Pixel, it works on any phone. However, Google's original Android suffers heavy modifications by 3rd parties, so Samsung, Xiaomi, Huawei, LG and others may introduce additional power saving measures than those originally implemented by Google. The Chargie app asks to be listed as a non-power optimized app at startup, and checks that each time, but it's still not enough for some phones. Our app presents itself as a foreground service, which means it has a notification that's visible to the user and should NOT be put to sleep by the operating system. Some phones don't respect that and you will sometimes wake up with 100% charge because if the Chargie app is put to sleep, there's no other entity (at least in HW v1) to send the "stop charge" signal to the physical device. Our next device will have a programmable timeout in its firmware and will be able to stop after a preset amount of time, even if the app is no longer controlling it. That makes for a safer charging method, as the battery won't stay fully charged for the entire time it's plugged in. We will implement a reporting feature that sends us the phone's physical characteristics (no personal data) whenever a 100% charge is attained  and held while using Chargie. That will be communicated in advance and you will be able to opt out. You can also check out https://dontkillmyapp.com to see various ways you can skip your phone's power saving measures for a specific app.