Chosen Solution
I just replaced the internal battery successfully using the guide here, but I noticed that the battery doesn’t go above 8%. I bought the battery at this website. It’s stuck at 8% for more than 2 hours and it says its fully charged (plug icon on battery)
I would just make sure that the battery cable is sitting flat and that any of the connections are not touching the board but only the contact. If the cable is not put on perfectly it can cause it to not fully charge up.
