Should I Keep My Laptop Battery Plugged In All The Time?
While we talk about new gadgets and software all the time, we often ignore the batteries that provide the required voltage and juice to power them. Our laptop batteries are one of the most important parts that often get ignored during high-octane discussions involving RAM, CPUs, and GPUs. Nevertheless, specific questions about the best practices for charging a laptop battery keep popping up regularly, like, “Should I keep my laptop plugged in all the time?” or “Should I drain my laptop battery completely before charging?“
Well, the answer to the questions above isn’t straightforward. Hence, before explaining, let us tell you some facts about your laptop battery that’ll help you understand the answer in one go.
How is the battery health measured?
The health of a battery is measured in cycles, which is the number of times you charge your device’s battery to its maximum capacity. Generally, it is considered a good idea to completely discharge and then fully charge your laptop at least once a month. This is called a “deep discharge,” which helps calibrate the battery. Calibration is vital for some features, such as remaining battery time, to work accurately.
Can you leave your laptop battery charging overnight?
The answer is no. Laptop batteries can not be overcharged, meaning as soon as they are 100% charged, they communicate with the charger to cut off the electricity supply and stop charging. Most laptop batteries are made of lithium-ion, an element designed to withstand multiple charge cycles before degrading and dying.
Now, computers are intelligent. They cut off the electricity supply to the battery once it’s fully charged; the same applies to smartphones. Hence, keeping your laptop plugged in overnight won’t harm your battery and doesn’t impact the overall battery life of your device in the long run. What does cause issues, though, is leaving your device plugged in overnight while it’s still on standby and not switched off.
Every time the battery discharges to 99%, the charger sends current, which impacts the battery life. Hence, if a device needs to be switched on overnight (like a smartphone), you shouldn’t leave it to charge overnight.
There are a few good practices that can extend the life of your laptop battery. Your battery has a finite number of charge-discharge cycles, so repeatedly discharging your battery will harm its overall longevity.
Heat is your battery’s greatest enemy!
You’ll be surprised to know that overheating is the most critical factor when it comes to the prolonged life of a battery. Keeping your laptop plugged in won’t kill your battery, but the heat will, gradually but much faster than charging your device overnight.
So, if your laptop’s CPU temperature is around 40ºC, keeping the laptop plugged in won’t cause harm. However, if your laptop has a removable battery and you wish to use it extensively, you are advised to remove it from the socket. However, this applies only to older laptops with replaceable batteries with latch mechanisms to remove them. You can’t do much on the modern ones.
There’s no solution to heat
According to the laws of thermodynamics, heat will always be a byproduct when transferring electricity. Here’s a table showing how much a Lithium-based battery’s overall capacity can diminish if we operate it at a specific temperature and battery percentage.
| Temperature | 40% charge | 100% charge |
| 0°C | 98% (after one year) | 94% (after one year) |
| 25°C | 96% (after one year) | 80% (after one year) |
| 40°C | 85% (after one year) | 65% (after one year) |
| 60°C | 75% (after one year) | 60% (after three months) |
According to the tests performed by Battery University, a battery that is charged 100 percent will have only 300-500 discharge cycles. On the other hand, if it’s charged to 70-80%, it’ll get 1000-2000 recharge cycles. You can apply this if you have a fairly modern laptop and want to extend its battery life.
What not to do to extend your battery life
- Avoid discharging your laptop completely after charging it. The best thing you can do is try to keep the battery level between 40 percent to 80 percent.
- Ensure your laptop doesn’t get too hot and your cooling fan is working properly.
- Your laptop battery can’t “overcharge” and harm itself due to excessive charging. It’s smart enough to talk to the charger and stop charging once it’s fully charged.
Make your laptop last longer
It is perfectly fine to keep your laptop plugged in all the time, as the concept of overcharging doesn’t apply to Lithium-ion batteries. However, it is important to avoid heating up your laptop too much because that has a negative effect on it. Additionally, you should try to completely discharge your battery and then charge it to 100% every once in a while. This helps keep your battery calibration fine-tuned so that your laptop can show accurate battery stats.
But can you follow the same practices for smartphones, the short answer is yes. However, there are other simple ways to extend your smartphone’s battery life. To get more popular laptop queries answered, find out if you need help deciding if it’s safe to use a battery charger of a different make. While you’re at it, check out the reason behind what causes a battery to explode.
