Time required for full charge from empty:
60Wh battery - 3 hours
100Wh battery - 6 hours
150Wh battery - 4 hours
222Wh battery - 6 hours
The reason why the 150Wh battery takes lesser time to fully charge than the 100Wh battery is because the 150Wh/222Wh batteries use a higher power 60W power adapter that charges faster than the 30W power adapter used by the 60Wh/100Wh batteries.