Charge time

I would stay away from it. Is is possible to use the timer during those mornings?

 

It's written in the owner's manual. Bolded below.

 

After reading that I would never BUY a Plug In Vehicle!

 

MMM,
Thanks for the manual citation. I overlooked that. Since we rarely drive the car after my wife gets home (to benefit from a charge), I will definitely take the time to learn and set the timer to charge in the wee hours.

 

Yep!
Set it and forget it!

 

The vehicle is intelligent about handling charging. You can plug it in, have it charge immediately, and not worry about overcharging. This is analogous to your cell phone. It won't overcharge either.

The timer is designed, in part, to be more "grid-friendly" if you want to charge during hours when electricity demand is lower. Additionally, for people with time of use rates, this is cheaper for them.

But, charging immediately and unplugging many hours later will not damage your car.

For battery life reduction from leaving fully charged for a while, in my opinion based on my experiences with Lithium Ion technology, 8 hours is no big deal. If you're going to be gone for days at a time, leaving the battery at a 50% state of charge is ideal.

Some other vehicles get around this by building in a buffer to the battery. For example, the Volt is "fully charged" when the physical battery is only at roughly 80%. The Prius may do this a bit as well, but I don't personally know. This type of buffering keeps the battery out of the non-linear charge state areas, which prevents degradation.

 

I think cell phone and laptop battery longevity is well known. Plug-in's are a whole new world. Nissan drastically changed their battery policies from avoid going over 80% SOC in the 2011 Leaf to 100% SOC is fine but watch out for high temperatures in the 2014 Leaf. In essence we are all participating in a beta test for Toyota.

 

This is a nice article discussing Lithium Ion battery life. While it's not for the PiP, the point should be that, when done right, the lifetime on these batteries should far exceed the vehicle itself.

Expert: What You Know About Lithium Batteries Is Wrong, Can Last Up To 20 Years | Inside EVs

 

I think people are thinking about this in black or white...as in, either it's fine or it's bad.

I don't think that is the right way to think about it.

I think the vast majority of owners would agree on here that you shouldn't leave it charged at maximum for several days. So if 48 hours is "bad," why would 10 or 12 hours be totally fine? It's obviously not as bad as 48 but it obviously is much worse than 0 or 1.

 

I totally agree.

I'll also add that when looking at used cars, all things being equal, we assume the lower mileage example will last longer than the higher mileage comparison. I look at the traction battery the same way. It has some finite lifetime. I can prolong its life by following these precautions or I can use it. Some of these precautions prevent me from using it. Like avoid frequently driving near the top speed of EV mode (My commute is 90% highway, I can't use up the battery on the other 10%) or never leaving the battery full for long. (Unscheduled errands on weekends will be spontaneous and the battery may not be full if it didn't charge overnight.)

I'll do my best to minimize these things like using the timer on weekdays and parking my car in the garage. When it comes time to sell, I'll have the high mileage well used traction battery. I choose to enjoy the benefits of EV mode than preserving the battery for the next owner.

Of course, if what I am doing is black and white bad for the battery, I would stop.

 

No. The system automatically stops at 85% capacity.

It never gets anywhere near close to 100%, so there's nothing to ever worry about.

 

And that's the important thing to note. Volt does the same thing. Leaf does not have nearly as much of a buffer. I'm not sure of the other vehicles.

The bottom line is, like most things these days, not all plug-ins are created equal. Those that do not use the full capacity of the full battery (Prius, Volt, etc.) should have a very long battery life without the concern for degradation, even when the vehicle is left "fully charged" for long periods of time.

 

I have had my PiP since April 2012. I used the charging timer for the first month of ownership. Since then, I've just plugged in and let the car sit with full charge overnight or for a few days even. The car still accepts 85% state of charge based upon the scan gauge. The car still gets roughly 13.5 to 14 miles of EV range.

 

I mean you can't push the HV button, drive to Subway, come home, and still have 9.5 EV miles. The PiP will use some of the charge whether you want it to or not. A perfectly good reason to switch to HV with a full EV charge would be when you know you're going straight uphill or onto the highway. Using EV to push the PiP up a steep grade is an inefficient use of the "balance of power," but Toyota doesn't give you a choice.

 

That's an interesting comment. Your request is for full retention, an imbalance.

Coming back down on the other side right away would allow an overcharge. The consumption of some upfront prevents that by providing a buffer. Same thing with highway driving.

 

I don't get it. You only have to push one button to use the timer. Everything else in the process is the same.

 

I would (I did) but someone keeps unplugging my charger. So I have to wait till it's dark outside (outlet on photocell) and plug in, then return outside when 3 hours has passed and unplug, hoping no one has unplugged me.

 

What a wonderful game! Not!

 

I don't think it recommends that.

What it says is "By using the charging timer function, deterioration of the hybrid battery
(traction battery) charge can be suppressed, and off-peak electricity
can be used effectively."

What does seem to be a consensus is that optimal long term storage is for when the battery is 40%-50% charged.

Note that when you come in off the road after a long trip, a 'fully discharged' battery is around 25% charged, and a 'fully charged' batter is about 80% charged (at least according to the State of Charge parameter from the onboard diagnostics.) So it doesn't seem obvious to me that waiting is a particularly good strategy for battery life. If you could charge to 40%, then wait, then top off to 80% that would be optimal, but I don't know if spending time at 25% is 'better' than spending time at 80%. And it would seem that "gee, I might want to use the car sooner than expected, so should start charging now" makes better use of my time, and outweighs the small cost of impact to the battery.

One caveat -- in cold weather, I would agree that completing the charge just before use is helpful -- because it warms up the components!

 

I don't use the time either, plug it in when I get home, and use the car when I need it , maybe only one to hours later or the next morning!