Hi Barb, the battery life depends greatly on how often the alarm goes off. If you're burning toast most days, the battery will not last 10 years. The wording you will often see now is 'long life' or 'up to 10 years' At PSL, Fire & Safety will offer a 5-year warranty on all our alarms (better than Apple 1 year warranty on their iPhones ;) However, if you have a problem with one of our products we will assist you, our customer service is excellent as you can see from our Google reviews. Thanks Lee