Laptops have limited battery life and an average battery life of three hours. The operating time depends on the tasks for which we use the laptop. For long-term operation, a powerful source of energy is required. It’s a power supply unit, also called a charger.
Notebook chargers are devices that charge the battery and directly power the device from the mains when the main lithium-ion battery module is depleted or defective. The charging adapter is a switching power supply. This adapter converts the mains voltage to the one needed by the laptop charge controller. On store shelves, you can find a great variety of chargers and adapters. All of them differ in output voltage, rated current, power, and also in the standard size of the power cord plug. If you are reading these lines, then you are probably faced with the need to buy a charger.
First of all, you need to pay attention to the manufacturer of the charger, as well as such points:
- Some companies are protected and may not charge the laptop if a non-original charger is connected, for example, HP and DELL. If in the case of HP, they figured out how to bypass the protection, then for DELL there must be a special DALLAS chip in which the charger ID and its power are stitched;
- The plug must match the make and model of the laptop. Each laptop manufacturer has its standard jacks for connecting a charger, each company has several varieties of “standard” plugs. Very rarely, chargers for one company can be suitable for another company;
- The input voltage is measured in volts (V) and indicates the voltage that can be supplied to the power supply from the mains. Please note that standards differ from country to country, so power supplies have different input voltage ratings. For Ukraine, the input voltage is 220-240 volts;
- The output voltage is the most important factor when choosing a power supply. It shows the voltage that will be supplied to your laptop. It must match the value indicated on the laptop. This indicator may differ from that indicated on the laptop by no more than 0.5 volts. At low values (less by 1 V), the laptop may not turn on. If the supply voltage is exceeded by 1 V or more, the risk of burning the laptop is higher.
Input and output current
Output current is measured in amperes. It is worth considering that if the output current is less than the laptop requires, then you risk burning the charger. If the charger is of poor quality, it can catch fire. Therefore, it is recommended to choose a charger where the output current corresponds to that indicated on the laptop or more. The bigger it is, the better.
Charger output power
Power output is measured in watts (W). This is an indicator that characterizes two parameters at once, current strength and output voltage. That is if the charger has an output voltage of 19 V and a current of 3.4 A, then the power of the charger will be equal to 19 V * 3.4 A = 64.6 W. Often these indicators are rounded and denote the power of the chargers in 15W increments.