A false technological myth says that leaving a laptop plugged into the power supply can ruin battery life, that's not really the case and let's see why
For those who work with a laptop on a daily basis, there is one aspect that is of particular importance: laptop battery life. There are several techniques to improve the battery life of the laptop, but the question that distresses many users is: if I keep the computer always connected to the power, will I ruin the battery?
Before answering this question we must understand that every lithium battery, not only that of notebooks but of most electronic devices, has finite charge and discharge cycles. This means that once we reach or exceed the maximum number of recharges we will begin to see a reduction in the efficiency of our computer battery. The autonomy of the laptop battery will therefore decrease steadily over time. This phenomenon occurs regardless of the type of battery in our notebook. On laptops at the moment either lithium-ion batteries or lithium-polymer batteries are almost always used.
Is it better to leave the PC always connected to the power?
If your question is: have I left my notebook always connected to the power, will I have reduced its battery life? The answer is no. A lithium battery, in fact, cannot be overcharged and damaged even if you leave it plugged in constantly to a power outlet. This is because as soon as the charge is complete, the internal circuit prevents further charging until a voltage drop occurs, i.e. until we unplug it. In reality it is much more dangerous for the life of the battery of our computer to use the notebook constantly with a flat battery. The advice is to plug in the device when the remaining autonomy drops below 30 or 20%. To discharge the battery of the computer is always not recommended. If done consistently it could significantly reduce the autonomy of our laptop.
Among other eventualities that we must monitor to avoid damaging the laptop's battery we find the high temperature and frequent power surges. In practice, the advice is not to charge the computer in a room with a temperature above 30 degrees and not to do so using a power line that is not very stable and subject to voltage drops or surges. These two aspects can negatively affect even in a short period of time the battery life of our device.
To have an optimal charge, studies on lithium batteries recommend to disconnect the notebook from the power when the charge reaches 70-75%. In this way it is true that the battery will last less because it has not reached 100%, but we will triple the number of charging cycles at maximum efficiency for the battery of our notebook.