I only charge my phones when needed. I have read numerous posts and articles that claim leaving a phone charging all the time will actually have a negative affect on the battery in the long run. If Fox was still around he used to post excellent articles about batteries and how to take care of them. Many of those posts are still here..... somewhere.
"Is it bad to leave your android charging overnight?
Yes, it's safe to leave your smartphone plugged into the charger overnight.
For years, the myth has persisted that plugging your smartphone in to charge while you sleep will harm the phone's battery. You don't have to think too hard about preserving your smartphone's battery — especially overnight. For years, the myth has persisted that plugging your smartphone in tocharge while you sleep will harm the phone's battery."
"Nowadays devices are really smart, they know they are full or drained. They slowly decrease the charging speed when it's almost full to prevent over heating. When it's full, it stops charging. Don't worry.
I've always left mine on .. especially when I wireless charge ....it might deplete battery a little bit over the lifespan of a phone but neglible IMO ...you most likely have a new phone by that time ...these phones are pretty good with battery management
I just got this one for my new 9+ and it seems to work well. If I leave it on there when I get home from work, late that night, after leaving it on the charger, there's no heat from the phone so I assume it's ok.