1st - running batteries down till device shuts down is not good for battery longevity. Best is between 20-80%.
2nd - a 23% charge level after overnight charge would indicate a battery problem. It is unlikely, but possible, that your charger quit overnight.
3rd - my android devices won't turn on with very low battery charge. I must get them up to a few % first. Your 2% may really be 9% now.