Résumé dans la langue de publication, traduction non disponible A battery protection circuit has an overcharge detection circuit that detects overcharge of a battery and a charge inhibition circuit that, when overcharge is detected, inhibits charging with a delay produced by a capacitance element. This charge inhibition circuit can detect a short circuit in the capacitance element that is used to produce a predetermined delay, and, when it detects a short circuit in the capacitance element, it inhibits charging without delay. Thus, since charging is inhibited even when the capacitance element is short-circuited, a power supply unit incorporating this battery protection circuit is safer to use.