Control charging and discharging of laptop battery

Solution 1:

40%~60% condition is recommended when you're not going to use your battery for a long time. If you bring your battery to a charge level of around 40%~60% and store it in a cold place, this will extend its life. I suggest storing it in refrigerator. It’s a good place but don't set the temperature too low, and remember not to fully discharge it to avoid electrolytic spillage. Here are some laptop battery tips that may be useful.

The biggest factor in battery life, especially for laptops, is the temperature at which the battery is kept. Another important thing is, storage or using at 100% charge is harmful. I think you should read this crucial article about "Lithium-ion battery preservation" for further info.

Solution 2:

You are right. In fact in EV cars(tesla etc) specialized firmware maintains charge between 30 & 80%. The battery never actually chrages upto 100%. It is also liquid cooled. This is to increase the life time of the battery. So two things are actually important: Heat and 100% charge. Both are harmful. You should not use it always at 100% charge, which is what will happen if you are always plugged in to AC adapter.

There is built in app for Samsung laptops & netbooks called Battery Life Extender which will limit charging to 80% in order to extend battery life. Try and find out if it is available for your laptop.

If you can't find an app, the only option is what I do in my ASUS G53, manually unplug it when it charged to 80-85% and replug when it is 20-25%. BatteryBar is Taskbar widget with modifiable settings for reminding you of ideal range.

Solution 3:

I think that the 40-60% is for storage when not in use. Otherwise Li-ion batteries' lifetime are limited by the number of full discharge/recharge cycles (if I remember correctly.)

Battery university is a great resource and tutorial for battery issues.