ASUS Zenbook 13.3-Inch Ultra-Slim Aluminum Laptop up to 8 hours of battery life with 2-week long battery standby and automatically backs up data when battery life is below 5%. ((UX305FA-ASM1))

With the new Intel Core M-5Y10 processor, 8GB of 1600MHz LPDDR3 memory and 256GB Solid State Drive, ZenBook UX305 starts up in seconds and keeps moving at a rapid fire pace as you open anything from web browsers to large programs. ASUS Super Hybrid Engine software gives you control and longer-lasting freedom for 2-second Instant On from resume, up to 8 hours of battery life with 2-week long battery standby and automatically backs up data when battery life is below 5%. 
battery display :45 Whrs Polymer Battery

High quality ASUS Zenbook UX305 3-cell laptop batteries

• Voltage: 11.4V
• Capacity: 3900mAh (45Wh)
• Chemical: Li-ion
• Color: Black
• Property: new original batteries
• Warranty: 9 months