iPad Pro 12.9-inch (5th generation)

Check the device in good light, with the screen on and off.

Look at the screen for cracks, dead pixels, lines, discolouration or burn-in.

On an iPhone, battery health is in Settings > Battery > Battery Health (on newer models, Battery Health & Charging).

Choose the condition where every point is true for your device. If it sits between two, choose the lower one.