Netbooks are not built for heavy tasks like gaming and don’t even come with such capable processor. Some netbooks pack dual-core Intel Atom processor but still are able provide decent battery life.
The battery life of netbooks listed by manufacturers differs from real-world battery life tests as there are many factors involved like change in screen brightness, WiFi usage hours and multitasking.
Some netbooks ship with larger 9 cell battery and some with 3 – 6 cell battery which effects the netbook battery life by a big margin. Larger batteries are bulkier and increase the weight of the netbook while thinner netbooks are apt to have shorter battery lives but are lighter to carry.
So, when you are looking to buy a new netbook with longer battery life , you must see your requirement. If you are looking to carry your netbook a lot, then you should go for a small netbook with 6 cell battery which can give you anywhere between 6- 11 hours of battery life . If you are low on budget, buy refurbished models or old models which ship with a little older processor.