I want to know what i have to do to build a healthy long-life battery

Hello, thank you for using Howly.
If you bought a new one, there is no need to worry about the life of your battery, because it comes from the factory in excellent condition and can provide different battery life depending on the model. It can always be connected to power supplies, but I recommend charging it till 100% and remove from it till get a 30% charge. This simple step will make your battery life longer
Try not to overheat the device, this will extend the life of all components, including the battery
You can always buy a new battery and remove it by yourself, if you think, that battery ends much faster than the new one
Li-poly batteries have their own life cycles and it took at least one year to see much difference between old the new batteries. Just don't make the battery feel less than 30% and it will have long life)
If you specify your notebook model I will give more detailed advice