A feed controller adopted to be included in a battery drive type device, the feed controller adopted to supply power to a predetermined load from a battery holder that obtains rated electromotive force from plural rated number of batteries having predetermined specification and connected in series while held by the battery holder, the feed controller includes: an outer casing attached to the battery holder in place of one of the plural batteries and having shape and size appropriate for being held by the battery holder; a converter unit disposed within the outer casing to receive voltage corresponding to the sum of the electromotive forces from the other batteries when the outer casing is held by the battery holder in place of the one battery and convert the supplied voltage to output voltage corresponding to the rated electromotive force; a switch unit inserted into a feed path for supplying the output from the converter unit to the predetermined load to open and close the feed path according to a feed control signal; and a feed control unit which generates the feed control signal to be supplied to the switch unit.