When using your new battery for the first time, you need to prime the battery by charging it to 100% and discharging it to 20% for 3 times. If you don't know how to install a new laptop battery, you can search "How to install a new laptop battery?" on website.
DO NOT let the battery drain to 0%: If you constantly let it drain to 0%, the battery becomes unstable will be seriously degraded.
DO NOT keep your battery always fully charged: Just like emptying your battery to 0%, keeping your battery permanently charged at 100% is very harmful. As time goes by, this will increase its internal resistance and reduce its capacity.
Perform regular charging cycles: If you don’t use your Laptop battery very often, it is important to cycle it (discharge => charge) regularly, at least once a month. Please store the unused battery fully charged. Do not store at low power to prevent reduce the lifespan of a battery.