Mobile phone and tablet adapters. Does voltage and ampere really matter?

You can use a higher ampere adapter for your device.

But be sure you have the same voltage.

Original adapter that came with your phone is

For example 5v 1.5a indicated on the adapter.

You can use a 5v 2.1a adapter.

The phone will only draw 1.0a, regardless of higher ampere adapters. Just be sure it is in the same voltage.

If your phone adapter is 5v 2.1a

It is not recommended to use an adapter with lower ampere.

For example:

Your phone adapter is 5v 2.1a

It is not recommended to use a 5v 1.0a adapter.

As it cause stress and heat to the adapter, because the phone cannot draw the sufficient amount it needs.

Same as your home appliances, you can plug a television with 50 watts and a lamp with 5 watts consumption in the same wall outlet. Because the device/appliances will only draw what it needs. But you cannot plug an appliances that exceeds the wattage capacity of your wall outlets.

Thank you for reading. :-)