I'm retired and have set my timer for 9pm at night Monday thru Sunday. We never use the vehicle at night and once in awile not even in the day. My question is, the last time we use the Prius the EV % is empty I plug it in at around 5pm. By 7am the next moring of course it fully charged. 1. Is it ok or will it do any harm to leave it plugged in for a few days without using the car. That would mean that at 9pm the following night it will try to charge and it should be near full. Or 2. Unplugg the vehicle after the first night. Then not using the car for a few days then Use the Prius and return it to my garage, plug it in and have it know to start charging at 9pm.
It is best to leave it plugged in, especially living in the north... like Maine. I'm in Minnesota, so the benefit of having the battery tended to while away is nice. That keeps it warm for you, preventing its temperature from dropping below freezing. That ensures the best performance. Lithium chemistry increases resistance significant when cold. Also, keep in mind that you can stop & start charging at any battery level. You don't need to completely empty it before recharging or completely recharge it before driving.
In the winter, I would leave it plugged in so that it can draw power to warm the battery. In the summer, I'd go with option 2 and just unplug it when it's done. (But there is no harm leaving it as far as I know). Also, for battery longevity, I would use the "Departure" setting rather than the "Start" setting. In other words, instead of starting the charge at 9pm, I would have the car end the charge at 7am (so it can start some time overnight). The idea is to reduce the time where the battery is sitting at full (called cold soak if I remember correctly).
The purpose of "cold soak" is to give the battery as much time as possible to rest between usage & charging. This maximizes longevity. So, the suggestion to set the timer for departure rather than start is good advice.
For moderate climates (like North California, Cupertino) : should i keep my charger plugged in if I only drive on the weekends? If I do keep the PiP plugged in at all times, does it do a lot of damage to the battery? Posted via the PriusChat mobile app.
None. Charging automatically stops at 83%. It never goes beyond that. So, there's no stress on the battery.
however, it would be a good idea not to charge your car on a regular basis, if you aren't going to drive it.
That's far too vague! Without detail, you're contributing to misconceptions. I suggest if you aren't going to be driving for at least a week, keep the change-level around 50%.
