The S-8243A/B is a series of lithium-ion rechargeable battery protection ICs incorporating high-accuracy battery protection circuits, a battery monitor amp and a voltage regulator which drives microcomputer and gas gauge IC. Combining microcomputer or gas gauge IC facilitates displaying a remaining amount of battery. The S-8243A/B is suitable for protection of 3-serial or 4-serial cell lithium-ion battery packs from overcharge, overdischarge and overcurrent.