Samsung galaxy tab 3 crashes unless kept plugged in?

[fashion lamp]

about 4 months ago my battery life hit rock bottom and I essentially stopped using my tablet, it refused to charge and when it did charge it didnt last. After replacing the battery, it became clear the problem was a broken charge port. That was also replaced. But to my disappointment the tablet is still nearly unusable. When unplugged from a charger, even when it reads at 100% (although the battery is inaccurate), the tablet stays on for a minute or two before dying without warning. When plugged in, it functions as expected, with the occassional crash when opening an app or without reason. I very recently (yesterday) factory reset the tablet, and nothing has improved, however about thirty minutes ago the tablet froze and the screen went white and it began screeching at maximum volume, refusing to shut off until I unplugged it. This is the opposite of an improvement.
Is this a documented issue? Would replacing the battery a second time fix it?

 

[Rukbat]

1. Charge it for 24 hours. The charge calibration may be SO far off that the battery is dying when it says 100%.

2. Are you sure you didn't get any wires piched, or maybe not have a wire pushed all the way into a connector, when you put it back together?

If you can't find the problem yourself, it's going to have to go to the shop.