If your laptop's battery life seems to be rapidly declining, a common charging habit you likely believe is beneficial could be the very thing causing the damage. An electrical engineer has stepped forward to clarify a widespread misconception about how we should charge our devices.
The Common Charging Mistake We All Make
Many laptop owners operate under the assumption that they should let their device's battery drain completely before plugging it back in. This practice, often thought to 'calibrate' the battery, is actually causing more harm than good. Experts from Tech Explain on TikTok, led by an electrical engineer, have set the record straight.
They insist that using your laptop while it's plugged into the mains is significantly less damaging to the battery than the cycle of repeatedly charging it from a low state and letting it die. The reason lies in the fundamental chemistry of the battery itself.
The Science Behind Your Laptop's Battery
The engineer explained that a lithium-ion battery functions through a chemical reaction. Each time you introduce electricity by charging it, this reaction occurs and contributes to the natural ageing process of the battery.
'Discharging and charging will basically make the capacity slower and slower,' the expert stated. The constant cycle of depletion and recharge places considerable strain on the battery's components, leading to a faster reduction in its overall capacity to hold a charge.
Contrary to popular fear, leaving a laptop plugged in after it reaches 100% is not 'overcharging' it. Modern devices are equipped with a smart chip known as a Battery Management Integrated Circuit (IC). When the battery hits full capacity, this chip intervenes and stops diverting the main electrical current to the battery.
At this point, your laptop begins to operate directly from the power source, much like a desktop computer, effectively giving the battery a rest.
Public Reaction and Important Caveats
The revelation left many social media users surprised. One commenter admitted, 'Wow... and I intentionally use my laptop until it's low before I recharge, thinking I was helping the battery health!' Another provided a real-world comparison: 'My brother and I bought the same MacBook Pro in 2013. I always used it plugged in, but he didn't. He changed the battery in 2019, and I will in January 2026.'
However, the engineer's advice comes with a crucial condition. This 'bypass charging' feature is dependent on the laptop's hardware. While most modern laptops possess this technology, older models and many phones may not, meaning the battery could continue to be stressed if left plugged in at 100% for extended periods without use.
For optimal long-term battery health, especially if you primarily use your laptop while connected to power, it is recommended to enable any built-in battery-saving mode. These modes, found on many devices, limit the maximum charge to around 60-80%, which is a more stable level for the battery chemistry when it is not required for portable use.
