Start up screen locked - Battery module signal

[AC Question]

My LG G5 wont start up. It has a battery module signal displayed and wont respond to hard or soft resets. Any ideas please guys?

 

[B. Diddy]

Welcome to Android Central! Do you mean that the only thing showing is the large battery icon that is typically present when the phone is powered off and plugged in? What happens if you press and hold Power for at least 15 seconds? Have you already tried a new or different battery?