Need help with battery

[panorama360]

Well, my phone was working fine, but from some days it was showing battery problem, battery backup was not good, but it was considerable.

But, u can understand my main problem in attachment. It was around 44% and suddenly shuts down. Battery goes to 0%.. Any help please.

 

[bosshaug12]

Try to do a few reboots if you can. Maybe even backup your data and do a factory reset just to be sure it't not a software glitch.

Your attachment shows the signs of a bad battery. Its pretty common on 2-3 year old phones or phones with simply a bad/defective battery. Your best bet is contacting Google or LG about the matter to see if they can do anything under warranty for you or repair it.
You could always replace the battery yourself, too.