This disclosure discloses a printer comprising a feeder, a thermal head, an energizing device configured to selectively energize heating elements of the thermal head, a driving device configured to control a driving of the feeder, a battery storage part, a voltage detecting device configured to detect an output voltage value of the battery, a display device, and a control device. The control device executes a dot count identification process where a dot count is identified at a first timing and a second timing, a dot voltage fluctuation value calculation process where a voltage fluctuation value per dot is calculated, a maximum load voltage estimation process where a voltage value of the battery is estimated at a time equivalent to maximum load, a consumption level determination process where a consumption level of the battery is determined, and a display process where a predetermined display is executed on the display device.