Nest Temperature Sensor vs Nest Temperature Sensor (2nd gen)

The Nest Temperature Sensor wins overall thanks to a better price and a higher rating. The Nest Temperature Sensor (2nd gen) only pulls ahead on battery life, rated at about three years on a CR2 cell versus two years on the original's CR123A.

The main difference is battery life: the 2nd gen is rated for about three years on a CR2 cell, while the original lasts around two years on a CR123A. Both function identically as room sensors for a Nest Thermostat with no humidity sensing, screen or third-party integrations, and the original Nest Temperature Sensor comes out ahead on price and rating.

No. Both the Nest Temperature Sensor and the Nest Temperature Sensor (2nd gen) are accessories that only work paired to a compatible Nest Thermostat, with no standalone Wi-Fi, Bluetooth or Matter connectivity of their own.

The Nest Temperature Sensor (2nd gen), rated at roughly three years on a CR2 battery, compared with about two years for the Nest Temperature Sensor on a CR123A. That is its only advantage over the original.

Buyers who want the same room-prioritizing function at a better price and with a higher rating than the newer model, and who don't mind swapping a CR123A cell about a year sooner.

Nest Thermostat owners who specifically want the longer three-year battery life on a CR2 cell and are willing to pay more and accept a slightly lower rating to get it.