The invention provides a method and device for predicting charging time of a battery. The method comprises the following steps of obtaining a charging starting capacity percentage and a charging ending capacity percentage of a to-be-charged battery to obtain a charging capacity percentage of the battery; carrying out analysis according to historical charging data of the battery to obtain a charging time coefficient; obtaining charging current and charging voltage of the battery in a current charging environment; and calculating charging time required for current charging of the battery according to the charging capacity percentage, the charging time coefficient, the charging current and the charging voltage. According to the method and the device for predicting the charging time of the battery, a charging time prediction error caused by the adoption of theoretical values of full battery capacity and charging efficiency can be reduced; analysis of the historical charging data and the charging time coefficient can be taken as a data basis for engineering improvement and personalized updating, repair and maintenance of the battery; and the historical charging data of the battery is periodically updated, so that the charging time coefficient has relatively good reference value.