Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Lasted 18 months

I bought this to do support 2 things -- battery backup for the Bluray player and the cable box -- a very light load. Our neighborhood gets lots of power flickers and having this happen when we're watching TV is a major pain.At the 18 month point (of a 36 month warranty) it started randomly shutting itself off. Items plugged into the surge-protector-only side still got power. Items plugged into the surge-protector-and-battery-backup side got ZERO power. It wasn't just that the battery stopped working, it's that it actively prevented connected components from working.I emailed Tripp Lite support and they said they'd replace the unit if I mailed it in first. I paid $11 for the mailing, but I figured it was still cheaper than buying another unit. Tripp Lite was pretty quick responding and they sent me a more powerful unit (550va) as a replacement.