The role of an Laptop AC Adapter/Charger and how it working

In Australia, the power outlets supply 240V (volts), but most laptops only need around 20V (volts) to operate.  The main function of a laptop AC Adapter/Charger is to reduce the 240V Power to a particular voltage that suits the laptop computer (or other devices for that matter).  Therefore, it is important to select the correct laptop AC Adapter/Charger if a replacement is required.

How to identify your laptop battery charger?

Every Laptop AC Adapter/Charger has a specific identifying number, Part Numbers are often printed on a sticker with manufacturer’s logo and details affixed to the AC Adapter/Charger.  Some manufacturers identify their AC Adapters/Chargers with the term “Types” (instead of Part No.).  The easiest way to identify your laptop computer AC Adapter/Charger, is to locate the part number, type it in to Google and you will get enough information to identify the AC Adapter/Charger.  If there is no part number or the sticker has been removed, the only other option is to look for other specifications of your AC Adapter/Charger, and then manually identify your AC Adapter/Charger.

There are 3 identifying aspects to a laptop AC Adapter/Charger when identifying one,

• input details
• output details
• the connector tip that plugs to the laptop’s power jack,
• some of these details can also be found underneath your laptop.

Here is an example of what to look for –

Input: 110-240, 50-60Hz (this is regional based, e.g. 240V in Australia)
Output 19V       3.45A (V=Voltage, A=Amps) Wattage is V x A (in this case 19 x 3.45 = 65W)

The only other part that differentiates an AC Adapter/Charger is the size and the type of connector, the best way to identify the connector is to measure the outer diameter of it using tape measure, ruler or calliper, the shape of the connectors are generally brand specific.