Okay, so we just reset one of the 6th Gen iPod Touches right now, along with an iPhone 7, iPhone 8, and iPhone 8 Plus and there is NO battery widget. To test things out we just paired different devices to the iPod and iPhones after resetting but before touching any other settings. Here are the results for the iPod Touch;
- Logitech K380 Keyboard - No battery widget shows up.
- Logitech K480 Keyboard - Battery widget pops up in the "Add More Widgets" section with percentage for both the iPod Touch and the keyboard.
The battery widget stays there even if we click "Forget This Device" in the Bluetooth settings. We then reset the iPod Touch again to factory default, verified there's no battery widget, and tried again with some headphones this time;
JLab BT Headphones - Battery widget pops up in the "Add More Widgets" section with percentage for both the iPod Touch and the headphones.
Once again, if we click "Forget This Device" in the Bluetooth settings the battery widget stays. Once again a 3rd reset, verified there's no battery widget, and we try another set on headphones;
SoundPeats BT Earbuds - Battery widget pops up in the "Add More Widgets" section with percentage for both the iPod Touch and the headphones.
So I can conclude the only way to get the battery widget to show up is to pair a Bluetooth device that sends battery information to the iPod Touch. Once it's paired, you can forget the device and the battery widget stays.
This is also the case on my iPhone 7, iPhone 8, or iPhone 8 Plus in which the battery widget only shows up when I pair a Bluetooth device that gives the battery status. Hope this helps.