The disclosure relates to a battery capacity meter and a lithium battery. The battery capacity meter includes: a meter housing having a mounting cavity formed inside the meter housing; and a circuit board assembly mounted in the mounting cavity, the circuit board assembly including a first circuit board, a second circuit board, a display component and a controller, the first circuit board and the second circuit board being stacked and electrically connected to each other, the display component being mounted on the first circuit board, and the controller being mounted on the second circuit board and electrically connected to the display component.