Canon EOS 77D Instruction Manual page 453

[Battery communication error. Does this battery/do these
batteries display the Canon logo?] is displayed.
Do not use any battery other than genuine Canon Battery Pack

LP-E17.
Remove and install the battery again (p.40).

If the electrical contacts are dirty, use a soft cloth to clean them.

The battery becomes exhausted quickly.
Use a fully-charged battery (p.38).

The battery performance may have degraded. See [53: Battery info.]

to check the battery's recharge performance level (p.421). If the
battery performance is poor, replace the battery with a new one.
The number of possible shots will decrease with any of the following

operations:
• Pressing the shutter button halfway for a prolonged period.
• Activating the AF frequently without taking a picture.
• Using the lens's Image Stabilizer.
• Using the LCD monitor frequently.
• Continuing Live View shooting or movie shooting for a prolonged
period.
• Using the Wi-Fi function.
• The Eye-Fi card's transmission is enabled.
The camera turns off by itself.
Auto power off is in effect. If you do not want auto power off to take

effect, set [52: Auto power off] to [Disable] (p.325).
Even if [52: Auto power off] is set to [Disable], the LCD monitor will

still turn off after the camera is left idle for approx. 30 min.
(The camera's power does not turn off.) Press the <B> button to
turn on the LCD monitor.
Troubleshooting Guide
453