【Battery Specifications】Battery type: Lithium polymer Voltage: 3.7V Capacity: 650mAh 2.4Whr 【Compatible Part Number】Compatible with TL284443 T3007ES T3008US A0013 T4000ES T4000E 【Compatible Models】Fit for Nest TL284443, Fits for Nest Learning Thermostat 2nd 3rd Generation 【Security & Reliability】Integrated intelligent control chip help you use TL284443 battery safer. Built-in over-charge, over-discharge, over-voltage, over-current and over-heating protections. Multiple circuit protection ensures both safety and stability. Exclusive offering of high performance and long lasting usage. 【Never Worry with Confidence Warranty】We're actually so confident in the performance of our spare batteries that we're including a 12-Months warranty 24 x 7 Email Support coverage with every single purchase. If anything goes wrong, please contact us by click "Contact Seller" from your order at any time. Pinsinholy TL284443 Battery for Nest Learning Thermostat 2nd 3rd Generation, Compatible with T3007ES T3008US T4000E T4000ES A0013 Smart Home Battery with Tools