Secondary battery charging device and secondary battery charging system

A secondary battery charging system (1) includes a secondary battery charging device (3) and a power generation device (2) that generates a charging current. The secondary battery charging device controls the charging a secondary battery (100), which has a protection timer that counts a first elapsed time from a start of charging. The secondary battery charging device includes a charging switch (32) that controls a supply of the charging current, a time management timer portion (34) that counts a second elapsed time starting from a point at which the charging switch becomes conductive and performs a charging stop determination and that counts a third elapsed time starting from a point at which the charging switch is cut off and performs a charging start determination, and a charging control portion (33) that causes the charging switch to be conductive or cut off based on results of the charging stop determination and the charging start determination.