Traffic Jam, Battery Goes South

if your battery gets low. let's say.. where you were. the engine will kick on to re charge it. at this point you ask yourself the question. save fuel or run the a/c.

I prefer to listen to a good song but at times i would rather just hear the road and other cars.

 

In a way yes it is normal don’t worry about it. I think the lowest the computer will let it get is one bar. I know from experience sitting in heavy traffic 100F+ so the ac was on that the battery stays on the low side. Red bars and the ice will kick in to bring you up to one blue. Once you start driving under normal conditions the ice will charge the battery back to the all blue bars were it likes to hang out.

You do not need to do anything different with the prius; just drive it. I ignore the battery when I am in a tbad traffic-jam as it is pointless just let the computer take care of it and try to relax.

 

The computer in the Prius is very protective of the battery. The ICE will kick on when needed. BTW, what you see on the MFD isn't the entire SOC, just between 40 to 80%, IIRC.

 

That's accurate, aaf709, the bars on the Energy Monitor display are:

0 bars = 40% charge
all green bars = 80% charge.

It's also accurate to say that there's nothing wrong with the charge state going up and down. It will drop down if you're creeping along for a while. This is a good thing because you're not using a lot of gas to creep along. I actually really get a kick out of rolling along in stop-and-go traffic with my engine off. You'll learn to love it too!

You can safely ignore the bars... that is until you've read a lot more of PriusChat and decide to try your hand at hypermiling

 

You may get better performance out of the Air Conditioner if you set a comfortable temp and leave it in auto. The compressor is electric and will run less if it isn't needed, and in Auto mode, the car monitors both interior temperature and humidity to keep you comfortable. When you're jammed in traffic, be comfortable and relaxed listening to your cool tunes, instead of getting hot and bothered like the other drivers. Your Prius always gives you the best economy it can in the situation.

Instead of looking at the low bars on the Energy screen, look at the high bars on the Consumption screen.

 

Be happy -

Your car is working as designed. If it were not using the battery while you sat there, it would be using gasoline inefficiently - like the rest of the cars around you.

Be happy.

 

<div class='quotetop'>QUOTE(PaneInTheGlass @ Apr 24 2007, 06:14 AM) [snapback]428914[/snapback]</div>

We need to coin a term for this, like "panic syndrome".

Pretty much every new owner that hadn't already encountered a panic discussion-thread before delivery will end up sharing a panic story of their own virtually identical to the experiences of other unaware newbies.

It's the same thing everytime. They begin to feel nervous when stuck in a traffic-jam, based solely on what they assume is happening to the battery-pack. That empowering Energy-Monitor leads them to the wrong conclusion, shutting everything but the car itself off and having to sweat out the remainder of the wait... only to find out later that all was running perfectly and no response was needed.

 

<div class='quotetop'>QUOTE(PaneInTheGlass @ Apr 24 2007, 03:05 AM) [snapback]428730[/snapback]</div>

You were VERY lucky to get out of that traffic jam in time. Any longer, and your Prius might have gone into the feared "destination unreachable" mode. That's when it determines you will never reach your destination before the battery dies or global warming causes the end of the world, whichever comes first. It then shuts down everything except the air conditioning and the MFD. The MFD will show unsolvable sudoku puzzles to distract you from what's happening. There is no known way to get out of this mode.

 

I agree, there is no need to intervene, let the car handle itself and you'll be fine.

I also find the Prius (2006) to do poorly in the traffic jam situation. I've only been in one really bad jam for a little over an hour. Probably 20 minutes into it, the battery was bottomed out, so now the ICE is flailing around wildly with every 'creep ahead' for the next 40 minutes.

In this situation where you might think it would do great on mpg, it does it's worst.

I'm a little surprised it doesn't decided to regen the battery at some point and run the engine at some efficient rpm level for 4 or 5 minutes to bring the battery up to a usable level so the ice can kick on and off a lot less for the next little while.

Then, when you break out of the traffic jam, your mpg is in the toilet as the battery eventually recovers.

They have some basic parameters around protecting the battery, but I don't think they did a lot of tinkering to make it do anything cool in this situation.

 

same thing happened to me last night infact while waiting to cross the tz bridge..
battery went down to two bars and stayed there. Got the worst milage ever after that for a good 5 min. Nothing to worry about .. the computer will take care of it

 

Further point: the main battery and associated electronics are cooled using *cabin* air, not outside air. That's the vent at the right end of the rear seat. You should use the A/C instead of opening a window, to avoid the possibility of the battery system getting too warm. If it does get too warm it will throttle itself and cause the car to run less efficiently. (Keeping the windows up also reduces infiltration of dust into the battery compartment.)

 

<div class='quotetop'>QUOTE(PaneInTheGlass @ Apr 23 2007, 09:05 PM) [snapback]428730[/snapback]</div>

Yes, mine will do the same thing when heavy electrical demands are made on the battery. I shut off the A/C & headlights the other morning. The battery is supposed to go up & down depending on the load.

 

It's actually quite bothersome when you're in a traffic jam, the battery charge drops very low and the ICE starts cycling on/off each time you move an inch forward and stop. To avoid this, step on the brake and press the gas pedal half way; the ICE will turn on, keep doing this until you get a couple of blue bars, take your foot off the pedal and the ICE will now stay off for a longer period of time.

A few folks have actually drag raced their Prius. They do the above, flooring the gas until the battery charges almost completely to obtain the best time.

 

<div class='quotetop'>QUOTE(jamarimutt @ Apr 24 2007, 04:15 PM) [snapback]429232[/snapback]</div>

I'm glad someone finally said this. When I first had the traffic jam experience, I was not so much concerned about the low battery, but driven nuts by the ICE cycling on and off. I mean, it was really monstrously annoying.

Is this a documented feature? I'll have to try this...

 

Be advised that the ICE/charge/battery behavior will also change depending on the temperature of the battery. You may never see the exact same behavior again.

 

Recall that you get down to "two pink bars" territory if the car's
sitting powered up in Park, too. That's the default state when *not*
actually driving, and apparently when just creeping along too [but
then the juice is actually being used for propulsion]. Still a bit
of a mystery why the sitting-in-park state doesn't seek the 60%
level instead, but that appears to just be how it works.
.
_H*