How to make the rechargeable battery in your smartphone, tablet or laptop last for years
Every battery has a finite lifespan, and this is given as the "recharge cycle" or "battery cycle." Put simply, this is the number of charge/discharge cycles that a battery is expected to endure before it is no longer fit for service. Some hardware manufacturers publish this figure while others do not. For example, Apple makes this information available, stating that the iPhone battery is designed to retain up to 80 percent of its original capacity at 500 full charge and discharge cycles, while the MacBook Pro or MacBook Air is designed to deliver up to 1000 full charge and discharge cycles before it reaches 80 percent of its original capacity.
You can find out how many times your MacBook's battery have been recharged by clicking on the Apple logo on the menu and then About This Mac, followed by the System Report button. From there, click on Power under Hardware and look for Cycle Count.
For a Windows 8 or Windows 10 system, fire up a Command Prompt and type in:
This will generate a report in HTML format and save it into your user account folder.
Some people think that they can dodge this charge and discharge by topping up their battery regularly so the battery doesn't get fully discharged. Unfortunately, as Star Trek's Mr Scott was fond of saying, "you cannae change the laws of physics." If you only let your battery discharge by 25 percent, then doing this four times counts as a single cycle. Same goes if you do five charges after 20 percent discharge, or even 20 recharges after 5 percent discharge.
What you can do though is prevent unnecessary cycles by keeping devices plugged in and charging where possible. However, be smart about this, only leave things plugged in when they are in use, and don't leave them on charge all the time as this can cause heat to build up, which itself will damage the battery.
In other words, don't put the battery through unnecessary cycles. Understand that I'm not saying keep the device on charge all the time -- that would also be bad for the battery because it needs a regular workout to keep its internal chemistry in good condition -- just be aware of wasting cycles.