Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works great when it holds a charge

This toothbrush works great when it holds a charge. The problem is that it doesn't hold a charge for very long anymore. I've owned this brush for 18 months and the battery life has slowly gotten worse over the past 6 months. Originally I would be able to brush without charging the battery for over one week. Now the brush won't hold a charge for two brushes (so it won't even last one day).I'm returning the brush to Phillips for a replacement since they will replace the brush inside two years.