my phone is not opening without the charger and with the charger it only shows battery full

[nishana]

my phone is lg optimus l9 and it wont turn on without charger and with the charger it only shows battery full

 

[Titillating]

If I had to guess (and I am most definitely guessing here), I'd say it was an issue with your battery. It looks like the battery is removable on your phone; you may want to purchase a replacement and see if it works. Replacement batteries are generally fairly inexpensive.