In Connection and sync settings, you can enable or disable background syncing for your Monero wallets. By default, all of your Monero wallets will sync in the background in Unobtrusive mode.
Cake Wallet uses native operating system background processes to preserve battery life, preserve device longevity, and mitigate user interference.
I havent actually seen this work yet. Though that could have a lot to do with my charging habits as i pull my phone off the charger when it gets to 80% and plug it in when it reaches 30%. However, its never on charge at the same time every day.
Unobtrusive (default): Attempts to background sync approximately once a day if all of these conditions are true: the device is charging, the device does not have a low battery, the device is not being actively used, and the device is on an unmetered connection (such as Wi-Fi).
Yeah, those conditions are met while its charging, but the charging time is not fixed. If it tried to do it at say midnight for example the "is charging" condition would almost never be met.