Do battery bars ever reach the top?

Driskill Mountain is 535 feet above sea level, but only 225 feet above it's surroundings. That would not fill the Battery. There may be somewhere in the Ozarks but the nearest may be the Talimena Scenic Drive from Arkansas to Oklahoma

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Talimena National Scenic Byway Explore the Talimena Scenic Drive - Talimena National Scenic Byway

 

Yes, quite a few times. But it doesn't stay there long. The computer is always at work trying to get me the best mpg possible.

 

Yes.
And if you ever do fill it up, the car's first priority will be to use up two bars, so you have room to hit the brakes. If it is 'full' the Prius can't save any more energy via braking, and will start the engine as an air pump to waste energy.

 

Agreed. The battery charge indicator ranges from roughly 40% (1-2 bars) actual charge to about 80% (~9 bars). The car takes care of itself just fine...

 

I'm a little confused.
So are car washesa theoretical (if rare) risk...or not?

I was recently parked in ready mode, a/C on. After like 30 or 40 mints (actually I forget how long....sometime during the hour I was parked there), the car autonomously turned the engine on, presumably to recharge the battery, which indexed was getting more. I assumed it was doing so to keep the battery in the healthy range of 40-80% charge.

Needles to say, I remained in Park (which I assume to be Neutral, or some version of that state).

If the car were in Neutral (in a car wash, or some such), And the battery became similarly low, would the engine in fact turn itself on, or would the battery simply drain itself completely? (and, would that affect the ability to restart the car ?)

Naive question, I know. Am new owner.

Thx much,
PNB

 

No.
Think of Park as D with a pawl stuck in the gears, so M/G2 can't move. Everything works like D except movement.

In N, all electrical power to both Motor/Generators is cut off, so the engine (if it is running) has nothing to push against so it can't move the car. Without M/G1 power you can't start the engine, the HV Battery is on it's own. Toyota is legally required to have a N, you are never required to use it. (If you choose to, one good use for N is to come to a complete stop in N once a month to be sure the friction brakes actually work) Generally, avoid N.

 

As Jim pointed out, when in Neutral, the Motor-Generators are electrically dead. If the engine is not spinning, there is no way to start it. If the engine is previously spinning, it can continue until fuel starvation, but has no live generator to produce electricity.

In Park, MG1 is still electrically live, both to start the engine, and to charge the battery.

This 'Neutral' choice is a federal safety requirement. In case of a runaway engine, it allows drivers to disconnect power to the wheels. Differing levels of operator familiarity with Neutral seem to explain why nearly all crashes from runaway engines occur with automatic-type transmissions, not with manual transmissions.

 

I have had the battery "gauge" be full on some occasions, mainly on long coasts. Considering the electric motor runs constantly I imagine it hardly ever has a chance to have full charge.

 

I have filled the 8 bars coming down Cadillac Mountain during the summer...

Here is what I don't get though, so it's filled, and engine braking in B mode still engaged, the rpms go up... but if the SoC of the battery is truly maxed, then why does the blue regen "chg" still show a blue dip when I step on the brakes? It can't get past the SoC so is it really charging or am I just wasting the brake padding and the blue doesn't mean any more regen is actually happening anymore?

 

I do not have a C so I am vague on your blue bar.

When you brake in B, Motor/Generator1 consumes energy by rotating the engine with no fuel. This allows M/G2 to generate electricity to power M/G1. As you brake harder and the engine spins faster, M/G2 'brakes' by converting rotation into electricity. Without engine braking, it could not 'brake' as there is no room in the battery for more electric charge. M/G2 is generating electricity consumed by M/G1 pushing the engine around. None is going to the battery.

Was that the question?

 

On the 400-ish mile trip home from dad's house yesterday, mine filled up 4 times.

3500 foot net elevation loss, probably more than 9000 foot gross loss.

 

I'm asking: Why does the regen "chg" indicator still show it recharging, even after there is no more room for the battery to charge?

 

Sorry. I have never been in a c, so I just do not know the fine points of your Instrument panel.

 

I'm sure that even if it reads as full there are still things using the battery to prevent it from being full or it's because the monitor is programmed to show charging.

 

On my Liftback, I just take it as a quirk of the display. In normal operation, braking always blanks the 'propulsion' side of the bar (EV or ICE) and lights up the 'chg' portion, whether it is regenerating or not.

Some designer probably decided that even when the regen kicks out for any reason (battery full, ice or pothole activates ABS, etc.), the display behavior doesn't change so as not to upset the driver into thinking that braking has failed.

 

The eight bars on the battery charge indicator don't have very good resolution - they don't show the difference between the battery being 90% vs. 95% charged, for example (bearing in mind that even "100%" still leaves some extra uncharged capacity behind the scenes to protect the battery and increase its longevity). When that top bar lights up the battery is probably only at something like 90% of allowed capacity, so you still have a bit of extra charge that can go into it.

If I'm driving down a long hill in "B" mode, the throttle indicator shows charge going back into the battery and the additional battery bars light up as the battery "fills up". After the last bar lights up charge keeps going into the battery for a while, but eventually the CVT shifts the engine into a higher gear - it does that because the battery is now full and regen can no longer provide the braking force. By shifting into a higher RPM band the braking force is provided by engine compression instead.