2-Power 15.0v, 4 cell, 42Wh Laptop Battery - replaces 42T4857

2-POWER's comprehensive range of lithium-ion & polymer battery packs provide unrivalled quality and reliability for virtually all laptop models.|Developed using high-grade cells from manufacturers including Samsung and Panasonic; 2-POWER batteries ensure speedy charging, dependable performance, and allow you to go for longer unplugged.|2-POWER's SmartWatch Protect monitors your device during charging and discharging, protecting your device and battery from short circuiting and over-heating.