One of the main reasons people buy Nest thermostats for their HVAC systems is because it comes with a rechargeable built-in battery or replaceable AAA alkaline batteries. So, theoretically, your thermostat will always have power. But as you are frequently receiving error messages that the battery is low there must be a reason why it is draining all the time. You wonder now whether you can troubleshoot and fix this problem by yourself?  The most common reason for the Nest thermostat’s low battery warning is the improper placement of the thermostat on its base. This will prevent the Nest thermostat from charging, which will drain its backup batteries. Removing the thermostat from its base and putting it back correctly will fix this issue. There are quite a few things you can check to try and find out why the battery is not charging. Let’s look at the most common things…