Hardware

My Nybble came with a rechargeable battery, I charged it until it had a green light rather than red and after all the calibration things, I open up the serial monitor only to have Nybble constantly making low battery noises and a "Low power: 0V" continously popping up in the monitor. I can't for the life of me figure out why. All wires are connected properly, but it just keeps happening. Please help.