Using The Ac Power Adapter; Charging The Battery; Maximizing The Battery Life - Lenovo ThinkPad X240s User Manual

Using the ac power adapter

The power to run your computer can come either from the lithium-ion (Li-ion) built-in battery, or from ac
power through the ac power adapter. While you use ac power, the battery charges automatically.
The ac power adapter that comes with your computer has two basic components:
• The transformer pack that converts ac power for use with the computer.
• The power cord that plugs into the ac outlet and into the transformer pack.
Attention: Using an improper power cord might cause severe damage to your computer.
Connecting the ac power adapter
To connect the ac power adapter, do the following:
Note: Ensure that you perform the actions in the order in which they are listed.
1. Plug the ac power adapter into an electrical outlet.
2. Connect the power cord to the transformer pack.
3. Connect the ac power adapter to the ac power connector of the computer.
Tips for using the ac power adapter
• When the ac power adapter is not in use, disconnect it from the electrical outlet.
• Do not bind the power cord tightly around the ac power adapter transformer pack when it is connected to
the transformer.
• Before you charge the battery, make sure that its temperature is at least 10°C (50°F).
• You can charge the battery when the ac power adapter is connected to the computer. You need to
charge the battery in any of the following situations:
– When the battery icon in the Windows notification area shows a low percentage of battery power
remaining.
– When the battery has not been used for a long time

Charging the battery

When you check battery status and find that the percentage of power remaining is low or when the power
alarm alerts you that the remaining power is low, you need to charge your battery.
If an ac outlet is convenient, plug the ac power adapter into it, and then insert the jack into the computer.
The battery will be fully charged in about three to six hours. The charging time is affected by the battery
size and the physical environment. You can check the battery charging status at any time through the
battery status icon in the Windows notification area.
Note: To maximize the life of the battery, the computer does not start recharging the battery if the remaining
power is greater than 95%.

Maximizing the battery life

To maximize the life of the battery, do the following:
• Use the battery until the charge is completely depleted.
• Recharge the battery completely before using it. You can see whether the battery is fully charged from the
battery status icon in the Windows notification area.
• Always use power-saving modes, such as sleep mode, and hibernation mode.
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User Guide