Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Batteries Don't Last

I purchased the wireless fenced containment system and two pack of backup batteries. I had seen advertisements that batteries lasted 3-6 months. Not for me. I received them at the end of July, and they just died on September 23. Just under two months, with the dog wearing a collar maybe an hour a day, and almost never testing the boundaries. I am happy with the containment system, but not with the battery life.