Technology as it should be!

A small, light and universal and still inexpensive power supply of a German (!) Manufacturer, which comes with a practical fabric bag. Both power cord (and from the power supply) approx one meter long. There is also a 25cm long Y-cable for the 5V USB output. With this cable you can load common cellphones and Apple devices. Three analog gauges simultaneously on the selected voltage in volts, and the current flowing (amperage) and the temperature in degrees Celsius.
Through the ads you can see how heavily loaded the AC adapter or even overloaded so always. And can intervene accordingly.
I once witnessed a simple power supply that when overloaded simply was just hot and then started to smell. (In the worst case can perhaps so light a fire ...)
Who needs long lines, ordered equal to a typical "Euro 8" cable. Already for a few Euros gets several meters. A USB extension cable makes charging of smartphones pleasant. From 2 euros.

Small (amateur) trip to the Electrical:
You can usually find information on any notebook a sticker required on the input voltage and the (maximum) Input current (amperage). This amperage varies naturally depending on what you been up to with his computer, how bright the screen is displayed and whether the battery is charging, etc.
Multiplying Volt with Ampere gets purchased from the laptop wattage. The power supply unit is designed according to the label on a maximum of 90 watts.