Instruct: Classify Amazon reviews into positive or negative sentiment
Query: reliable performance

I bought these batteries initially 3 years ago before a trip to Alaska. They worked great all day, every day. I just charged them up at night and they were ready for another full day of sight-seeing and picture taking. Now, after three years of pretty consistent use, they no longer hold a charge for very long. I think they had a pretty good run, so, I just bought my second set.