[header] How to change the batteries in your smoke detector [title] Check the battery type. [step] Installing the new batteries incorrectly, or using the wrong type, will cause your smoke detector to not function. Always make sure you are using the correct type of battery and installing the batteries correctly to ensure the detector will work. 
[substeps] Detectors that use lithium batteries will last for ten years. You generally cannot replace the battery, instead, replace the entire detector after its ten year life span is expired.