LG Optimus G Pro Battery Charging Problems

[AC Question]

Hi! Had my LG Optimus G pro for 4 years, and am going to find it very hard to replace, as it is a great phone, works well, and I recommend it greatly. However I have had a problem recently. When my phone is on, it charges perfectly and functions normally.
However, if it dies and I plug it in, it doesn't display the charging display or even power on. All that happens is the two buttons on the front turn on. It just sits there. Then, hours later, it randomly turns on, usually at about 8% battery. Any fix or idea this may be happening?

 

[chanchan05]

A nee battery perhaps?

 

[Rukbat]

1. If you've regularly let the battery die for 4 years, it's gone - replace it. (Doing that for a couple of months can permanently kill a battery - recharge it at 40% or greater charge. Lithium may be light, but a lithium battery is not a deep-discharge battery.)

2. Charging a fully discharged battery takes at least an hour to precharge it, then a couple of hours to charge it (if you're lucky and haven't ruined the battery - which I suspect you have). So the first hour or two (or more if the battery is really ruined) isn't actually charging it.