With USB-C power adapters, it's not the wattage on the packaging that matters, but how that power is distributed among the ports. A 140W charger delivers 140W to one port – as soon as a second device is plugged in, the power is split.

For notebooks, at least one port should continuously deliver 65W or more. Otherwise, MacBook Pro and powerful Windows notebooks will charge slowly or not at all under load.

For smartphones and tablets, 20 to 30W is sufficient. More power will not further reduce charging time, as the devices themselves throttle.

GaN instead of silicon: Power adapters with gallium nitride are significantly smaller for the same power and run cooler. For travel and home office, a GaN multi-port power adapter replaces three individual chargers in your luggage.

Look for Power Delivery (PD): Only with PD can the device and power adapter negotiate the appropriate voltage. Power adapters without PD charge modern devices at standard speed, regardless of the stated wattage.

With USB-C power adapters, it's not the wattage on the packaging that matters, but how that power is distributed among the ports. A 140W charger delivers 140W to one port – as soon as a second device is plugged in, the power is split.

For notebooks, at least one port should continuously deliver 65W or more. Otherwise, MacBook Pro and powerful Windows notebooks will charge slowly or not at all under load.

For smartphones and tablets, 20 to 30W is sufficient. More power will not further reduce charging time, as the devices themselves throttle.

GaN instead of silicon: Power adapters with gallium nitride are significantly smaller for the same power and run cooler. For travel and home office, a GaN multi-port power adapter replaces three individual chargers in your luggage.

Look for Power Delivery (PD): Only with PD can the device and power adapter negotiate the appropriate voltage. Power adapters without PD charge modern devices at standard speed, regardless of the stated wattage.