It isn't always possible to be near an outlet to keep a charger running. A laptop is supposed to be portable. But a user may still need to be on their computer more than just 2 or 3 hours their batteries allow them. That can turn into a real problem if the person can't keep their computer running because was ist kobalt its battery just died.
To avoid this you can check date of manufacture and buy one that is more recently out the gates of the factory. As a workaround you can buy any netbook while it's under warranty test the battery and if it's not up lithium facts to your expectations you can send it back as dead on arrival and demand for a replace.
2) Battery freshness: often overlooked. Always make sure you have the freshest battery possible. A battery can lose it's ability to hold a charge as time goes on. You want batteries that move off of shelves quickly to be sure they aren't old.
Why lithium bettery stock is this important? If you have a relatively new PC the only problem you will get are error messages relating to the clock on start up. No big deal. If your PC is older then a low battery could be a nightmare. I had a PC which once every few months refused to boot. Rather than take the PC in for repair or start replacing parts myself the first thing I did was look at the BIOS settings. It was soon obvious that the BIOS settings were corrupt (wrong bus speed). I put a volt meter on the battery and sure enough it was reading 2.2 volts.
In terms of charging these powerful cells, when specifically used in an LED flashlight, special chargers are available all over the internet. Most will handle a 18650 battery as well as a variety of other Li-ion sizes.
Using these easy tips to keep the battery in the best condition won't do wonders, but will let you use it to the maximum number of recharges. Ever wondered why some laptops keep their maximum capacity for 3-4 years, while others dive under an hour of runtime in one? This is why.