Chosen Solution
So, back to February 14, 2018, my family had all gotten new phones, all being iPhone 8 plus. I had upgraded my old iPhone 6s to an 8 but I never got rid of my 6s because my favorite band signed the back of it, so i kept it for a backup phone. But it was kind of neglected on the dresser in my parents room since the night that we switched. This morning I tried testing out turning it on with the charger. It accepted the charger and after a few minutes it would normally turn on w/ me holding the power button, but that wasnt the case. It still showed the battery w the red line but wouldnt turn on. So I left to the store w my charger because i play my music in the car from my phone and when I got back home, I put the phone back on and kind of forgot about it for like five hours. I just got back to it and it is still showing the battery with the red line. I dont know if its taking forever because I had neglected it for so long and it needs time to charge what. I would assume thats the case but I wanna know what other people think I should do, if I can even do anything.
Probably going to need to replace the battery: iPhone 6s Battery Replacement iPhone 6s Battery