Li-ion battery pack and method of outputting DC power supply from the Li-ion battery pack to a power hand tool

A lithium-ion battery pack for outputting DC power supply at a specific voltage level, the lithium-ion battery pack comprising:

• a battery box including a lithium-ion battery having a positive pole and a negative pole and a capacitance at the specific voltage level between the positive pole and the negative pole, and a protection circuit having a switching terminal set, a high-level terminal set, and a low-level terminal set electrically connected to the negative pole of the lithium-ion battery;
• and
• a conductive contact holder mounted on the battery box and provided with a first plug with a positive-pole contact piece and a signal contact piece respectively electrically connected to the positive pole of the lithium-ion battery and the high-level terminal set of the protection circuit, a second plug with a charging contact piece electrically connected to the negative pole of the lithium-ion battery, and a third plug with a negative-pole contact piece electrically connected to the switching terminal set of the protection circuit.