Hi @subbumani
It could be a faulty battery.
Create a [https://www.groovypost.com/howto/generate-battery-report-windows-10/|battery report] to check the condition of the battery.
When you have the report, compare the ''Design Capacity'' value versus the ''Full Charge Capacity'' value. For a good battery they should nearly be the same.
If it is determined that the battery is faulty and needs to be replaced, here's the [https://download.lenovo.com/consumer/mobiles_pub/lenovo_n23_hmm_201607.pdf|hardware maintenance manual] for the laptop.
Go to p.35 to view the procedure to remove/replace the battery. On p.55 item #2 you'll find the part numbers for batteries that are compatible with the laptop. Search online using the ''part number only'' to find suppliers that suit you best.