How Long Should A Battery Last In A Smoke Detector. With the battery removed press and hold the test button for 15-20 seconds. Answer 1 of 4.
A smoke detector with a lithium battery or a hard-wired smoke detector can last 10 years at which time you would just replace the whole unit. I just binned them and didnt bother to make any note of the ac. Ad Every Month We Help Millions Find the Best Smoke Detector More.
But for years people have debated whether AA or 9V batteries last the longest.
Yet they use the same technology and so have the same shelf life. Smoke detectors powered by lithium or long-life batteries are designed to last up to 10 years. If the landlord is uncertain check the unit itself for date of manufacture. Long-life battery smoke detectors use lithium batteries to power them.
