Energy management display.

[FaFa]

After my 11 month wait I am the happy owner my new "Silver Slipper". In the two weeks that I have driven the car I have noticed that I have only once, very briefly, obtained a full green bar display. The display always is one or two bars down. When driving at high speeds for a period of time the bars will even turn blue for a while. I think this means that the hybrid battery system is off line, because thats what it looks like when in accessory mode.
I asked the dealer about this and he said that is normal for the Prius. Any comments on this.

Fafa

[guyboston]

I have never had all three bars lit, even after long highway drives.

[finman]

All green means about 80% full, as full as the system will allow. Down to 1 or two pink bars means about 40%, and as low as the sytem will allow. This helps the battery last much longer than if allowed to be completely full or completely drained. Blue bars are normal range. It does NOT mean they are 'offline', just within normal specs. All systems normal. I have seen 1 pink bar going up long mountains, but then all green on the other side. Love my Prius!

[efusco]

I'm not sure what "all 3 bars lit" means, and the original question is a little unclear too.

Below is a graphic from john1701a's site showing the colors of the various SOC levels:


Note that when the charge is up to the top two bars all the bars are green. When it is anywhere in the mid range it is blue. When down to either of the last two bars they are pink.

Also note that the distance you drive has nothing to do with how many bars you'll get on the battery SOC screen....in fact, the farther you go the more likely you are to stay at about 5-6 bars (blue) unless there are steep uphill or downhill areas.

[Tideland Prius]

Hey Evan,

is it me or does the battery seem to last longer when it's in 5-6 bars than when it's 3-4 (given that it's a warm engine so stealth mode is available).

So I guess in other words, are the bars an exponential indicator of SOC?

[efusco]

moved to more appropriate forum

<div class='quotetop'>QUOTE(Tideland Prius\";p=\"74897)</div>

Hey Evan,

is it me or does the battery seem to last longer when it's in 5-6 bars than when it's 3-4 (given that it's a warm engine so stealth mode is available).

So I guess in other words, are the bars an exponential indicator of SOC?[/b]

Someone over in the Yahoo 2G group did some tables looking at the discharge rate. I think that it was fairly linear, but there was some variation from test to test and depending upon whether it was charging or discharging.

Also, the SOC measurement is not very precise in real time while in use. You may notice that if you glide or coast or brake to a stop for a long distance or on a down hill that when you're stopping the SOC is at 5-6 bars. Next thing you know...after you've come to a stop, the thing's jumped up to 7 green bars! Likewise on the D/C side I've noticed this, esp. with the EV button, but even in normal driving if the traffic is slow moving and I'm in stealth it'll show 4-5 blues when I come to a stop, then before I take off, or just after it'll jump down/drop down to 2-3 bars.

Once the battery is in a steady state (ie. not being drained or charged) the SOC is more accurate b/c the voltage has normalized.

[DanMan32]

I believe it was Attila that discovered the bars are not linear in charge state, and also there is some histeresis moving up or down between bars.

[Dr.Jay]

Going on 6 weeks for my Prius and I have never seen 8 bars.
Only once or twice has it hit 7, then only on a 1/2 mile down-hill coast after leaving expressway.
Seems to hang right at 6.
It will drop to 5 bars momentarily but quickly back up to 6 and never higher unless I am coasting down hill.

[jeromep]

I see seven bars almost daily. Although we don't consider this region violently hilly, it basically has a lot of topographical elements. Going to work in the morning it is a gradual downhill drive. By the time I reach downtown I am at 7 bars and usually keep that all the way into the parking garage. On the way home I usually hover around 5 or 6 bars. I have never seen red. Then again I haven't gone over the pass in the car yet, so we'll see when it happens.