can you use a 19v 3.1 amp charger on a laptop that uses a 19v 2.1amp

Solution
As long as the voltage is the same and the charger's amperage is equal or greater than required by the load. BTW, be sure to check the polarity and size of the connector that plugs into the laptop. There are many sizes.
As long as the voltage is the same and the charger's amperage is equal or greater than required by the load. BTW, be sure to check the polarity and size of the connector that plugs into the laptop. There are many sizes.
 
Solution