Low battery phone shows it's charging but not turning on

Hi,

Lately my iPhone 6 Plus has been having weird issues regarding battery and charging. Normally, I put my phone on charge overnight and would wake up to a full battery phone but now when I would wake up, my battery would be dead shown by the low battery screen (black screen with low battery symbol in center). I would unplug it multiple times and eventually it would charge.

A day ago, my phone did the same thing; die even when it was put on charge overnight. I plugged it in again and it would say that it was charging. For me, it doesn't take long for my phone to boot up after it has been dead so once I checked on my phone and it said it was still charging I was confused. I left it on for an hour and came back to check on it to find that it was still dead but the screen said it was charging. I've tried many chargers and adapters, including an official Apple accessories but to no avail.

I must also add that my home button is also broken so rebooting and all of those solutions which include me to use the home button are out of the question.

I must admit it is an old phone and I plan on buying a new phone sometime soon but for now I'm left with this phone.

Every suggestion is appreciated. Thanks.