User interface systems for head-worn computers

A wearable head device comprising:

• a display;
• a frame adapted to position the display in front of an eye of a user of the wearable head device;
• a battery internal to the wearable head device, wherein power is delivered from the battery to the wearable head device;
• and
• a tactile effects system, wherein:
• the tactile effects system is configured to couple to the battery, and
• the battery is configured to provide power to the tactile effects system when the tactile effects system is coupled to the battery,
• wherein the tactile effects system is configured to provide vibration or haptic feedback to the user.