generally laptop battery made from Li-Ion and this Li-lon durability just about 4-5 years, more often your battery charged thats make the battery diminish durability. but don't worry I have way to make your battery more durable.
1. put your laptop on the hard place
warm is the most reason why laptop battery lost the durability, you should never put your laptop on to soft place like bed, pillow, soft mattress, etc.
2. ensure the stable power
don't use unstable power to charge your laptop, I recommend you use stabilizer electric power to charge your laptop.
3. shoul the battery disceonnected ?
the answer yes and no. if your laptop equipped switch when the battery was full you not must disconnected your battery. but if your not, you can disconnected the battery and use pure power from the electric panel.
4. defrag your hardisk
defrag your hardisk periodically it make your battery more durable.
5. hibernate & standby
switch to hibernate and leave standby habit.
6. clean your contact battery
clean your contact battery one a month, use fabric or cotton with alcohol to make battery power transfer more efficient.
7. hardisk & CD room
as much as posible use hardisk, don't use CD room chause CD room consuming power worse than hardisk.
8. power option
use optimize, theres will use maximum power to show maximal effect.
9. external device
turn off external device like bluetooth, wifi, etc if you not use it.
more big RAM is much better.