Hi Nina,

if this is a sudden change in your laptop's battery, then you need to take it seriously and understand the cause of this issue. In order to help maximize your battery life, it's important to first understand what drains the power from your laptop battery, and in a modern laptop it's the LCD panel.

Also, if you've got an unpowered hard drive plugged into your laptop through a USB port, it's going to drain your battery more quickly than if you had a powered one.

You can try the below fixes in order to keep your battery safe from draining fast.

Fix 1: Tweak Your Power Plan Settings
The high performance plan is always tempting (you're a high performance user, after all), but you'll burn through your battery a lot more quickly, so select the Power saver or Balanced plans, and make sure it's set to turn off the display quickly after inactivity, since that's the biggest power drain.

The Power Options screen opens and from here you can select from three predefined plans–Balanced, Power saver, or High performance.


Fix 2: Adjust Advanced Power settings
Make sure that the On battery settings are set to maximize battery life—change the plan to turn off the hard disk quickly, use the low-power mode for your wireless adapter, processor, and especially your graphics card.
The System cooling policy setting allows you to specify whether the laptop will rely on fans for cooling, or slow the processor down when the temperature gets out of hand, and can definitely help your battery life, though at the cost of some performance.


Fix 3: Adjust the Screen Brightness
The quickest way to save your battery life is to use your laptop's hardware buttons to control the screen brightness—most laptops require holding down the function key and using the brightness keys, and turning it down as far as you can (while still visible) is a good idea.

1. Select Start , choose Settings , then select System > Display. 
2. Under Brightness and color, move the Change brightness slider to adjust the brightness.

Fix 4: Let the computer cool down.
If your laptop battery feels very hot to the touch, excess heat could be interfering with the charging process.
Shut down the computer and let it sit for several minutes to cool down. If you haven't cleaned your laptop vents recently, blow a can of compressed air into the fan vents at an angle, in short bursts, to remove some dust.

Fix 5: Full Recharge
If your battery can't hold its charge anymore and drains extremely fast, you might be able to save it by doing a full recharge. You'll need to completely drain the battery for this to work, so once it reaches zero percent, keep turning it back on until it doesn't even have enough power to boot. Now, plug in the power cord and let the battery charge for at least 12 hours.

I hope this helps.

Regards,
Lokesh