Nest Learning Thermostat 2nd Generation Repairability Score: 9 out of 10 (10 is easiest to repair)

Battery is clearly intended to be user-replaceable (with built-in directions) and can be removed with the included Phillips screwdriver.

Solid construction surrounded by a hefty steel ring makes for great durability.

Separation of components onto two motherboards increases modularity.

Light adhesive holds the front panel assembly together, slightly increasing difficulty of replacing the LCD or glass.