Problem with the battery or charger

Recently I attended an auction an purchased the black and grey UE Boom 2 with white volume buttons. I got home and charged it for around 2 hours and proceeded to turn it on. When checking the battery by similtanously pressing the buttons it said 100% but not even a minute later it turned off with the message battery critically low please charge. Now I’ve used diffrent chargers that worked with my other speakers (eliminating the cable for source of error) however when charging I believe a white LED should activate leading me to belive the error in the port but I am unsure wether the problem lies within the port or the battery itself.

Thank you all answers can help!