Task: Analyze the tweet's emotional connotations and classify it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best portray the tweeter's mental state.
Tweet: Since the 'update' my @iPhone loses power nearly 40% faster.
This tweet contains emotions: 
anger, disgust, sadness