Battery Bars on Energy Screen

http://home.earthlink.net/~graham1/MyToyot...PriusFrames.htm

http://john1701a.com/prius/prius-how.htm
http://john1701a.com

 

The Multi-Display only shows the mid-range. So even when all the bars disappear, the battery-pack still has a decent amount of energy available.

Since Prius is a "full" hybrid, electricity will come straight from the engine when the level on the pack is low. So there is never any concern... though it does sound different from a traditional car. The engine is pushed up against the firewall in the smaller than usual hood area and it is pumping using an Atkinson cucle. So do believe the impression your ears give you.

As for that 63 mph comment, I'm guessing that you instinctively responded the way most newbies do... by being afraid to drop the pedal to the floor. Allowing the computer to determine RPM for you is totally normal in a Prius. The habit of manually protected the engine by not giving it full-throttle is not necessary.

As for me, I haven't ever needed to floor it... which is a good thing, because there is almost always a slow-poke in front. Some pretty agressive driving was required with my Classic Prius during the Hybrid Road Rally. Passing in the 80's happened quite a few times without any trouble. With the HSD (2004) it is even easier.

 

Eventually you may from time to time, especially if you go down long steep hills.

Another way you might entice it to go to green, is to decelerate from a high speed to 0, especially in a decline, like a long, decending off ramp.

But you don't need to force it to do anything. It likes to stay at 6 bars so you have enough energy for acceleration boosts, and provide electrical power during "idle" (like power for AC), and you have enough capture room for regeneration.

The bars are not linear. Bar six has the most range between its bottom and its top. Also there is a hysteresis from when you go up to the next bar, and when you come down from the next bar.

 

Green bars are pretty rare, but I generlly get them everyday on my commute to work. I live in the foothills west of Denver and drive into the City (downhill) every day. I usually end up with 1 green bar by the time I get to work. But on the drive home, I usually drain the battery to 1 or 2 red bars.

But the car manages the battery for you, and in layman terms, tries to keep the battery near the "midpoint" of its charge state. If the battery is above average charge (say one green bar), the car will rely more heavily on the battery and it is easier to get the car to go into "golf cart" mode, thus causing the battery to discharge. If the battery is in a low state of charge, the car will rely more heavily on the engine, and it is harder to get the engine to shut off (unless you drive really slow or stop).

The result of this is that the car does not respond to the accelerator pedal as predictably as a normal car, and sometimes the engine will race even though you aren't pressing down very hard. But don't worry, the car seems pretty foolproof to me, and I should be a good a judge!

 

Is it normal for the Prius to have 2 battery bars (from 6 bars) if you did not drive it for 3 - 4 days?

 

<div class='quotetop'>QUOTE(silverbell @ Nov 8 2007, 02:24 PM) [snapback]536813[/snapback]</div>

If the car was left on for those 3 - 4 days, sure. If it was turned off with 6 bars, it seems unlikely that it would register 2 bars when tuned on. 5 is certainly possible, and 4 wouldn't be a complete surprise, but I'd only expect 2 if I had left it on.

 

<div class='quotetop'>QUOTE(Danny Hamilton @ Nov 8 2007, 02:58 PM) [snapback]536828[/snapback]</div>

I power off the system but all I get is 2-3 bars after 4 days of NOT driving the Prius. I wonder if I'm the only one... :huh:

 

<div class='quotetop'>QUOTE(silverbell @ Nov 8 2007, 08:02 PM) [snapback]536956[/snapback]</div>

Normally you don't lose much battery charge from just sitting for a few days, but there are other factors that cause the battery display to change. When you start your Prius, the system examines the battery and tries to get a good read on battery state of charge (SOC). Often the SOC will be adjusted down a bit based on temperature and other conditions. Also, the battery is used heavily right after a start. The control system tries to take it easy on the engine until it warms up, which helps keep emissions low. This tends to drop the SOC a bit right after start.

To boil it down to a short answer, don't sweat a drop of a few bars over a few days. If it drops all the way down every time, or drops a lot over a short period of non-use, then you might have a problem, but what you describe sounds pretty normal.

Tom

 

I agree that the Prius is very smart. Ours is 2005 Silver. My theory is the slingshot (especially on Interstate) where whenever the engine turns itself on, I accelerate to about five miles or so above the speed I want to be driving and then ever to very slightly ease off on the pedal. I find that the engine generally stops running and on a four-hour trip I-95 I believe I spend as much as three of those hours essentially in golf-cart mode, even at a speed like 70 mph, when NOT going up an incline. I call it slingshot because I make the most of downhill run (even slightly downhill) and keep the pedal slightly heavy than steady to keep the car moving but not engaging the engine. However, when the Prius (computer) itself engages the engine, then I do a variation on the "floor it" to get as quickly as possible to the 5 mph above where I want to be, then back off ever so slightly. On large part of a tank of gas, I can get higher than the epa 60 miles per gallon on highway (interstate, including the increase that invariably happens when I take exit ramp at end of my trip and drive local street speeds of about 35 mph. Even with two passengers and luggage and AC in the warm weather (windows always closed) I can get about 52 mpg and DW with the heavy foot can get 42 mpg and better. She is learning. It is primarily her car.