Why isn't my iPad air getting charged?

Hi. my iPad responds or recognizes the charger being plugged in but dose not charges (i eve used different chargers to check if it was my chargers fault but NO) and after like 3 hours of charging it shows only the apple symbol and if remove its the same thing dose not have charge at all asks for charging again so….should just replace the battery or is there some other problem …? (and apple store is charging 2000 INR just for check up and its like day light robbery so asking for help over here )