Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great upgrade

Having worn out my original 14.4v red ni-cad batteries, I was reluctant at first to spend the money on these batteries, they aren't cheap. BUT,now that it's been a month or so with them, it's good to see they aren't cheap. I cannot believe the improvement these Ni-mh batteries are over the ni-cads. Even when the ni-cads were new, they can't hold a candle to these ni-mh batteries. Very happy with my investment of these, makes my job easier AND more productive having batteries that last between charge cycles.