For the past few years, most tablets, laptops and smartphones use lithium-ion batteries. Even the oldest Lenovo models of our supported laptops, the T60/61 (circa 2006) use this type. Lithium-ion’s lack of discharge memory and resistance to damage from deep discharge, are quite amazing, when compared to earlier battery types.
First, know that heat is most damaging to the battery’s capacity. Keeping your smartphone in your pocket or tablet in the sun (i.e.; room temperature or more), for a year, can cut overall battery capacity by 20%. Likewise, keeping your device plugged in, will make it run at higher temperatures.
Unlike older rechargeable battery types, lithium-ion batteries have virtually no discharge memory. This refers to batteries, when repeatedly discharged to say a 40% charge, then recharged, become unable to discharge beyond 40% charge.
Ideally, do ‘shallow” (20%) discharges most of the time, then charge and remove from the charger. While regularly running your device until the battery is completely drained, is hard on the battery (Think about the heat generated, when completely recharging.), it’s still a good idea to do that about once a month to recalibrate the charge level indicator.
One of the coolest charging methods is wireless charging. Unfortunately, it produces excessive heat, so it’s very hard on battery life.
To get the most runtime, on Windows laptops, make sure you are using the “Power saver” power plan.
In short, discharge as much as you need, to get your job done, but if you have the opportunity to recharge when down to 80%, do it, and then remove your device from the charger.