Brakes now charging e-battery?

This is not a new thing. It's how the Prime works. The brakes always charge the battery unless you brake very hard or are going under about 7 mph. There is only one hybrid battery. If it's above about 23% actual (as opposed to displayed) charge, EV mode is permitted. Below that is HV only. Once the EV range has been used up, it does take quite a bit of regeneration to get it up to the point where the car will allow EV mode again and when it does, it might suddenly show a few miles of range. That 23% is sort of like a pressure switch that shuts off your well pump at 30 psi and doesn't start it till it's down to 25. It won't keep enabling EV and disabling it just for a couple percent. Usually, it takes a long downhill stretch, but sometimes, if you hit a series of red lights in rapid succession, it'll regenerate enough to get you a little EV range.

 

What setting are you referring to? I'm sure there were hundreds of things they didn't tell you about.

The salesmen are so profoundly ignorant about this car and it is so sophisticated that you will never be able to use it and enjoy it anywhere near its potential without spending plenty of time in the owners manual. I suggest downloading the PDF version at toyota.com/owners and then you'll have it available on your computer, phone, tablet, etc. and be able to search for anything way more easily and quickly.

BTW, it might prove helpful if you edit your profile to say which model of Prime you actually have. There are some significant differences and there is no such thing as a trim 4 Prime. It's LE, XLE, or Limited. (unless it's a little older, in which case it's Plus, Premium, or Advanced)

BTW #2, we're all still learning.

 

My dealer didn’t know that holding down the EV/HV mode button would allow the engine to start charging the battery, as long as the displayed charge was below 80%.

By the way, there will be a 200 question multiple choice test after your first 2 years of using your prime, but only on the first 700 pages of the manual.

 

how do you charge a battery that's already 100% full?

 

I'm not sure what a "100%" battery charge display while running, really means on a Gen4 Prius Prime.

I have have an ~200ft steep downhill road from my near my house. I'll be in EV mode, and sometimes, I can get back to 100% before I get even near the bottom (at least another 1/3 downhill left).
However, the display still shows the battery charging. Iirc, it does that regardless if I'm using the brakes down the I've gone downhill with just my brakes, or I use "B" mode. The engine doesn't start.

So, maybe "100%" on the display is more of an small range?
Or, the display is showing that the battery is charging, but is actually using some of the brakes?

I have to hit things just right, and drive for efficiency. Also, no AC or heater, windows mostly up. Otherwise, by the time I get to that hill, I've lost to much battery charge to get back to 100%, by the bottom.
Also, I have neither the time or patience to try to "hyper mile".

Being New England, I of course have up hills(two much smaller hills), before I get to top of the big downhill.
Imho, no such thing as naturally flat and level land in New England.
Coastlines don't count, since they are barely a blip in geological terms (especially New England coastlines).

Fyi, for people that don't live by a coast, the coastlines are constantly changing/moving/reshaping/etc. That's been know for ?centuries?. Yet, you see a lot of houses right on/next-to a beach. Sigh...
Some more info: https://earthobservatory.nasa.gov/world-of-change/CapeCod

 

There is no such button. All trims are the same when it comes to HV/EV driving. If the battery is already charged to 100%, there is nothing to charge except for a small buffer. Regenerative braking doesn't charge more than about a percent (usually a lot less) unless you're going downhill. The battery state of charge (SOC) is kept approximately at the initial level during HV driving (if the initial level is 1% or higher), albeit in regular practice, it will decrease a few percent after each trip.

 

Yes it is, although I can't quite tell if that's the same thing that edward was referring to. The "small range" according to my ScanGauge II is that a full plug-in charge is actually 83% SOC and the lower end of the 100% "small range" is actually 81% SOC. For reference, when the display gets to 0% and goes into hybrid mode, that is 14% SOC.

 

is this thread satire?

 

okay, it must be:

charging-e-battery-while-driving.233029

 

I'm pretty sure that the OP is talking about the non-obvious charge-mode setting (push and hold the button for ~2-10 secs).
It's mentioned in maybe one sentence, in a manual that is 100 times longer than War And Piece.

See:
Prius Prime: detail about Charge-Mode
Prius Prime: detail about Charge-Mode | PriusChat

 

i'm not sure the o/p knows what he's talking about

 

Imho, I think the OP had questions that I would expect that 99% of Prius Prime owners would have.
Imho, all reasonable questions.

One question was was about how/why using the brakes charges the traction battery.
Another question was about the "hidden" charge-mode option of operation.

How using the brakes can create power/electricity is not obvious to the non physics/engineer.
People "accept" that alternators, wind mills, hydro electric plants, and even solar cells, "do their stuff".

As I understand, another, different question, was about the "hidden/non-obvious" Prius Prime "charge mode" operation.

 

nothing wrong with questions, but let me ask you this:

why would one open a thread asking a question, get several competent responses and only reply once, with a response no one understands,
and then open another thread the next day asking the same question all over again, and not respond to that thread either?

 

sound like Charge Mode to anyone else?

if it's charge mode that would be MG1 (Motor Generator 1) doing the charging.

Regen Braking confusses a LOT of people. It's actually MG1 and sometimes MG2 in the Prime that is regenerating the charge back into the traction pack.
It's not the friction brakes magically generating electricity.
If you know what engine braking is, when an ICE (internal combustion engine) or more commonly known as a (gasoline engine) slows the car when the driver releases the gas pedal, it's similar to that except it's the electic motor / generator (in the Prius there are 2 MG1 and MG2 ) one of which in a regular Prius is dedicated Generator. In the Prius Prime both MG1 and MG2 can be either a drive motor and or a generator, just not Both motor and generator at the same time..
Less confusing? or More confusing?

edit: I also learned something today while searching for a reference link to share. It's pretty complicated and has nothing to do directly with regen braking, and i'm also not sure about the description of heretical mode where MG1 in a regular prius can act as a motor.
And if I understand @ChapmanF description of heretical mode, it not a driver controlled mode, but rather a mode the ECM (Engine Control Module) controls.
motor/generator | PriusChat

 

see his other thread, it's not charge mode

 

Thanks for the heads up about the other post @edward smith made today at 5 pm, I just read it and IMO one of the ECUs (Electronic Control Units) controls the charging in the Prius all the time. And both the regular prius and the Prius Prime can charge the traction pack whenever that ECU signals the motor generators to charge the traction pack. It's not something the driver controls normally, but can be manipulated using several techniques to ask (for lack of a better description) the ECU to signal MG1 to send electricity to the traction pack.

 

As vvillovv mentioned, things get much more confusing with the Prime, verses a typical hybrid (like the Prius Hybrid).

For the Prime, there are now "potentially two electric drive motors".
And, one of those is an electric drive motor for the wheels, and an electric power generator for the hybrid/traction battery, and it's also the engine starter.
Wow!
Plus, the Prime adds a one-way clutch the the gas-engine.


Understanding how Hybrids work is hard.
Understanding how Pure Battery powered vehicles work is hard.
Understanding, and properly designing, a Plug-in Gas/Electric is Very Hard.

Just ask Honda, and look at their mega-disaster "Clarity".
I was waiting, and waiting, and waiting for the Honda Clarity to stop being a flaming pile of ******.
Eventually, Honda said Doh! A (reliable) Plug-in Gas/Electrical vehicle is far past the ability that Honda could hopefully ever achieve.
Hence, the cancelled Honda Clarity.

 

@prius16 If I'd seen your post above #14, before I posted #16 above, I would have definitely changed my wording to agree with you rather than asking if it sounded like charge mode to anyone else.
I had to giggle at the reference to war and peace.
thanks for breaking my streak of boredom these last few days. Everyone seems so damned serious around here (here?) at times.

I don't think I typed here twice, but there it was. Not my typical hear here writing style either.