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 lithium ion battery stocks 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.
The price of an external laptop battery may vary from brand to brand. But they are quite affordable and very compact device. They can be recharged with an external charger so you don't have to look out for an electric supply to charge the external battery.
But that means that laptops need to have bigger batteries and bigger batteries mean bigger size. Laptops won't be portable and convenient to carry in this case. That's the reason why laptops have compact batteries that gives it a sleek look. But these batteries don't lithium bettery stock have good battery-life.
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.
Recharge the battery to full again and repeat the above steps a few more times. This will allow you to use the battery for a longer time and you can do this no more than once a month. Replacement batteries can be expensive and stretching out their use when you are on a budget can help.