Palm Power 3S 300mAh battery with a high 65C discharge rate and JST connector and balance lead for charging.  Viper upgrade, great antweight (1 pound) class battery.   

Note: If using on a lifter with a servo a Voltage Regulator is needed to step down the voltage to the servo.  

 Specifications:

• Capacity: 300mAh
• Voltage: 3 Cell / 11.1V
  
• Discharge: 65C
  
• Weight: 25.4g
  
• Dimensions: 48.2x17x18mm
  
• Discharge plug: JST