Requires iOS 5 and Siri Capability
Use Siri to get an estimate of your battery life stats. BatteryLevelAE provides you with rough estimates of your battery life in different situations. Ask Siri things such as "How much talk time do I have?" or "How much audio time do I have" and she responds back with her estimate based on your battery life and Apple's official stats for your iDevice. For a list of things you can ask Siri Say "Battery Help Menu"
AssistantExtensions will be installed. Enable this plugin from Settings
See larger Screenshots below