My soundcore motion boom started having issues with it's charging port. Then it would shut itself off after a few minutes, even when I managed to get it charged.

Eventually, it wouldn't turn on at all, so I completely disassembled it and tried manually charging the battery. I also tried swapping in a different 7.4v battery. With an (almost) full charge of 8.2v of output, the speaker will turn on an connect- but it shuts itself back down after about 10 seconds. Every time.

Help???