At what level should I charge my Galaxy S5? And can I leave it plugged in even if fully charged?

[AC Question]

I am brand new to the smartphone world (came from an antique Env2) so I'm not sure when is the best time to charge my phone. In the old days, we were supposed to let the battery level drop until it was fairly low before recharging, as we were warned that if we didn't do that the battery "memory" would get stuck at a lower level and eventually the battery would never be able to hold a full charge again.

That said, I've been letting my battery level drop to the point where the phone will warn me that I need to charge it or else (somewhere below 20%). However, tonight a tech person told me that I should always charge it before the level drops below 50% or my phone will eventually not be able to hold a full charge. That seemed kind of weird so I wanted to double check if that was true or not.

He also told me that I should not charge my phone overnight, as the battery would overcharge and I would eventually burn out my battery, but when I looked at posts regarding that on this forum, everyone said that phones were designed so that there was no way they would overcharge. I sometimes leave mine plugged in after it's fully charged because I am reading a downloaded book and that way I don't have to worry about draining it down while I am reading. However, I don't want to do that if that will mess up my battery. So which is true, okay to leave plugged in even when showing 100% charge, or not?

Thanks so much for any responses!

 

[B. Diddy]

Welcome to Android Central! With modern batteries, you can charge them whenever you want--there's no such thing as "memory." All modern smartphones also have smart circuitry that will prevent overcharging, so there is no problem keeping it plugged in.