Batteries are made to be used, so use them.
Just like couch potatoes, batteries need exercise. The chemicals in Lithium-Ion batteries respond best to regular recharging. So if you have a laptop, don’t keep it plugged in all the time; go ahead and let it drain to about 40 or 50 percent of capacity, and then recharge your computer.
The life of a Lithium-Ion battery can be measured in charge cycles. A charge cycle occurs when 100% of a battery’s capacity is used. Let’s say you use 50% of your laptop’s battery one day, charge it overnight, and then you use 50% of the battery again the next day. Even after charging it back up again, you’ll have only had one charge cycle occur. Most laptop batteries are rated for a useful life of at least 300-500 charge cycles, but high-quality, properly maintained batteries can retain up to 80% of their original life, even after 300 cycles.
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The care and feeding of Li-Ion batteries | User Support | TechRepublic.com