Instruct: Classify the given review into positive or negative sentiment.
Query: Disappointed, 1-3 years for me

Installed 7 of these on dual-sensor Firex smoke alarms back on March 19, 2009, and just replaced the third (fourth?) one tonight. The first one only lasted a little over 6 months, but that alarm had a bad wire in the AC wiring so it was probably running on battery the whole time. The next one lasted just over a year (and I think there was another one that failed around the same time), and now I just replaced another one.Very disappointed. For the price, I'd rather buy regular Duracell or Energizer batteries and just replace them every 18-24 months.