Help, non tech savvy person. Please explain
Dec 20 17:55:10 localhost com.apple.backupd-helper[71]: Not starting scheduled Time Machine backup - computer is on battery power.
Dec 20 17:55:28 Daniels-MacBook-Pro.local com.apple.backupd-helper[214]: Not starting scheduled Time Machine backup - computer is on battery power.
Dec 20 18:08:12 Daniels-MacBook-Pro.local com.apple.backupd-helper[308]: Not starting scheduled Time Machine backup - computer is on battery power.
Dec 20 18:55:16 Daniels-MacBook-Pro.local com.apple.backupd-helper[384]: Not starting scheduled Time Machine backup - computer is on battery power.
Dec 20 19:34:19 Daniels-MacBook-Pro.local com.apple.backupd-helper[398]: Not starting Time Machine backup after wake - failed to resolve alias to backup volume.
Dec 20 19:34:32 Daniels-MacBook-Pro com.apple.launchd.peruser.501[137] ([0x0-0x59059].backupd-helper[398]): Exited: Terminated: 15
Dec 20 19:39:29 Daniels-MacBook-Pro.local com.apple.backupd-helper[232]: Not starting scheduled Time Machine backup - computer is on battery power.
Dec 20 19:41:44 Daniels-MacBook-Pro.local com.apple.backupd-helper[261]: Not starting scheduled Time Machine backup - computer is on battery power.
Dec 20 19:51:51 Daniels-MacBook-Pro.local com.apple.backupd[342]: Starting automatic backup
Dec 20 19:51:52 Daniels-MacBook-Pro.local com.apple.backupd[342]: Backing up to: /Volumes/External/Backups.backupdb
Dec 20 19:51:54 Daniels-MacBook-Pro.local com.apple.backupd[342]: Using file event preflight for MacBook Pro
Dec 20 19:52:02 Daniels-MacBook-Pro.local com.apple.backupd[342]: Will copy (10.49 GB) from MacBook Pro
Dec 20 19:52:02 Daniels-MacBook-Pro.local com.apple.backupd[342]: Found 4970 files (11.49 GB) needing backup
Dec 20 19:52:02 Daniels-MacBook-Pro.local com.apple.backupd[342]: 14.48 GB required (including padding), 400.34 GB available