I' have a new Prime, and a new job. My daily commute is about 20 miles. I can make it there and back without going out of EV mode. The most convenient thing for me to do is to charge the car overnight. I've been plugging it in when I get home but make I should wait until bedtime? Can you damage the system by overcharging or too frequent charging??
Use the charge timer. Set it for departure around the time you leave each morning. No, you can't damage it but you can extend the lifetime of the battery by doing what I said.
Smart battery systems will prevent the battery from being overcharged by gradually reducing charge rate as it gets closer to full, and then stopping the charge when full. So there's no danger of damaging anything.
It is highly recommended that you plug in for as long as possible. Pre-Conditioning of the cabin and cold-soak (rest time) for the battery requires delay. That's why there is a programmable schedule. Just set & forget. Simply plug in when you get home. There is never a concern about overcharging.
"Set it, and forget it." - Ron Popeil Seriously, and Ron is right, just plug it in. Charging schedule or not, the car just turns off the charging when it is at 100%. Simply unplug the charge cord before you leave.
Just plug it in but use the charge schedule to set a "Departure Time". This will mean the car will delay the charging and wait until some time overnight to start charging such that it will be full before you set off. That is the best way to ensure battery longevity. This is contrary to plugging it in and letting it charge immediately. This will result in a "cold soak" or basically the battery sitting at full charge for several hours. Other benefits of leaving it plugged in is the ability to use wall power for pre-conditioning the cabin (e.g. you can set your departure time and turn "Climate" to "On" so that once it finishes charging, it'll start cooling the cabin [or heating in the winter]) and have it at a more comfortable temperature when you depart). It may not be applicable to you but those of us in colder climates will also benefit from the traction battery heater when the car is plugged in. The car will draw a little bit of power to keep the battery warmer (above 32°F) so reduce battery inefficiencies and allow the owner to have access to more of the stored battery power. (IIRC, a cold battery won't allow as much discharge as a battery that is warmer).
Although you get a few people that like to just plug it in right away when you get home and not worry about the timer, you might as well use the timer. That's what it's there for. Plus it should extend the battery life a little bit.
