Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Risky Purchase

This battery arrived partially charged with 5 recharge cycles reported through the system monitor. The battery installed quickly and easily with the same fit as the factory Apple battery. Fully charging the battery took about an hour, but I noticed that the reported capacity was only 3900 mAh, well below the rated 4400 mAh. I fully discharged and recharged the battery a dozen times during the first weekend, but never got higher than 4000 mAh. During one of the later recharge cycles the battery got very hot along with the original Apple charger, then the charger failed before I could unplug the power cord from an APC surge protector.On a positive note, Amazon quickly fulfilled the order using the free delivery option, and quickly processed a refund when the battery fan hot and destroyed an otherwise perfectly good charger.