Replacement TL284443 Battery, for Nest Learning Thermostat 3rd Generation, Learning Thermostat 2nd Generation, A0013/T3007ES/T3008US/T4000ES

Seriously? This was expensive & only lasted 3.5 months & was so frustrating to install

I was racking my brain trying to figure out why my AC was short cycling (turns out it was a clogged drain that needed clearing). I researched Nest issues and thought it was a battery issue. I fought this so much and almost considered rewiring the whole thermostat, but ultimately realized it was the clogged drain. I don’t have a common wire on my nest and it charges when the system is running instead of having constant power. Short cycling = not running long enough to charge the Nest and made me think it was a battery issue when it wasn’t. The battery was cheap enough and I’m not upset about buying it, but just rule out everything else before you go replacing the battery - YouTube is an amazing resource for DIY HVAC troubleshooting.

Battery was not fully charged lasted no more than hour when installed.

Wiring harness different and destroyed my nest thermostat!

See above

for my thermostat, good product