external battery for notebooks (M-UPS-L7)

Weight: about 750g
Charging Input: 16V, 4.5A by AC adaptor
 Discharging Output: Voltage: 16～19V (adjustable)
Current: ≤3.5A
Max Output Power: 40W (when the output voltage is more than 16V and less than 19V)
       45W (when the output voltage is less than 16V)
 Charging time: about 4～5 hours
 Output Capacity: 66.6Wh/6000mAH
 Cycling life; at least 300 times. The life is terminated when its discharging capacity is less than 80% of the nominal capacity for 3 consecutive times.
 Dimension: 230?65?2 mm