Why can't my LAVA IRIS ATOM 2 SWITCH ON after i kept it un used for probably 4 month?

[AC Question]

I was on an exam so i kept my phone away lock away on my trunk box so after i was done giving my exam i took it out after 4 month probably but i can't switch it on again even after charging it for the whole night...
Could u please help me solve my problem Sir.?

 

[B. Diddy]

Welcome to Android Central! Try pressing and holding Power for at least 15 seconds. If nothing happens, then the battery might have completely discharged, which means it's dead. Try a new battery.