EV mode

There's a section on this in the manual. In my experience it tends to be because there isn't sufficient charge in the batteries.

 

Or the car's not warmed up enough. I've seen it too, and commented on it in this other thread:

http://priuschat.com/forums/gen-iii...ode-dropping-out-electric-vehicle-21-mph.html

 

I have the same issues with EV mode. I have tried to use EV mode many times when I think the EV mode conditions are met and have gotten the "EV mode not available" message. I'm sure I have 6/7/8 bars, the ICE is warmed up, haven't been under prolonged braking/charging, and I'm under 25 MPH and can even be stopped. I don't really have any feedback from the car on what might be preventing EV mode. Has anybody else had this happen and do you know what might be causing this?

 

The owners manual says one of reasons is "The temperature of the hybrid system is high."

Ken@Japan

 

I can only report that my EV mode has been very predictable. It cuts out somewhere between 25 and 30. It wont come in on a cold start or even if the car has only been sitting an hour. It will not come on with a low battery. It cuts out when the battery is 2 bars (or is it one). If the car is warm, the speed is slow, the battery full it will go in and stay in as long as I use a light peddle and it has charge. I routinely go the last 3/4 mile on EV and get at home with about 4 bars if I start full.

Eventually I'll try to figure out if this is helping or hurting my millage.

 

After owning a Prius for over a month, I've learned that there is never any need to switch to EV mode. If the battery has enough charge and the car is warmed up, whenever you drive slowly, the car will disengage the ICE (hence, you are in EV mode). In fact, in ECO mode, I can drive down the sidestreets to my house faster than in EV mode and still have the ICE disengaged. I think EV mode is more of a "gadget", something they threw in so salesmen could tout it and show it off. I never use it anymore; I simply take my foot off the accelerator for a moment until the ICE disengages, then drive slowly, the same way I would drive in EV mode. I don't have to worry about the "Excessive Speed" notice (unless I gun it) and I get all of EV mode's benefits.

 

Just used EV mode for the first time in heavy stop and go traffic. Works like a charm and I was able to drain the battery enough to exit EV mode. Too bad, I can see where a good lithium traction battery pack would help out here.

 

After less than 24 hours with my 2010 (and 2 years with a 2008) I am observing the same thing, however, the EV mode does work well in parking lots, very slow traffic and other places where you're not going to speed up. It's not a gimmick, I believe it is very useful, however the behavior of ECO mode does negate much of the value. If I had EV on our 2008 (haven't installed it yet) I believe it would be a huge win.

 

I think the EV has uses, just not real useful. I don't use it, I believe using the Battery is inefficient, except under unusual circumstances for me. For example I have never had the need to reposition the car from one spot to another. That would be an example of when the EV would be useful, I think.

 

I'm not sure why you think the battery is inefficient. Electric power is the most efficient mode of locomotion, far more than using the ICE. Excess power bled off by the ICE running in generator mode is like getting free gas.

 

I'm new to the 2010 (less than 24 hours). On our 2008 we always seemed to have excess charge in the battery, at least driving around town, unless I went to severely feathering the throttle and serious pulse and glide where I would drain the battery in acceleration. The bottom line, excess charge always seemed to be around. I find that to be extremely inefficient. The only place I can think of where there might be some validity is perhaps on a flat highway, into a headwind, on a cold day at a steady speed. Most of my driving is stop-and-go, bumper-to-bumper, etc. For longer hauls I use our SUV. It also seems that the regenerative braking is more efficient on the 2010 than the 2008. The battery seems to charge up much more under braking. Again, less than 24 hours into the 2010 so I don't have much of a sample set yet.

 

Why do you think the charge was excess? Were you driving around with all green bars? Typically this only happens when the ICE is called upon for heat. EV mode doesn't help in this situation.

Tom

 

City driving (stop and go) regenerates current to the traction battery. If you don't use what you regenerate you end up with a surplus. The 2008 accumulates excess charge that way.

Also, when I say "EV mode" there are two different meanings. The first is the switch and the status light on the dash. That's hard EV mode and a function of the switch. The second is when the ICE is off and the traction battery is supplying power to the traction motor. That's also in EV mode.

Which EV mode are you talking about?

 

I also think it depends on whether or not you've spent time trying to hypermile a pre-2010. My reference frame is comparing our 2008 to our 2010. What I'm finding is getting 60MPH on the 2010 is a piece of cake compared to our 2008. I can consistently get above 57MPH on the 2008 but it's very difficult to get the battery down to 3 bars or less (meaning excess charge exists as it normalizes closer to a full battery).

 

Hmmm... I can cruise all day long at 70MPH very easily.

 

I hope the previous post was a typo and what they really meant was MPG not MPH...

 

I did an experiment and found out I was wrong. There is a slight difference between the "official" EV mode ECO mode's implementation of it.

If I am in ECO mode at a full stop, I can accelerate slowly without the ICE coming on. I can accelerate well past the 22-23 mile per hour limit imposed by EV mode.

However, I must keep the power bar to the left of the line that divides it in the middle. Otherwise the ICE kicks in.

In EV mode, I can press the accelerator much further, well into the the right side of the power bar, and the ICE will not kick in. I can get faster acceleration, as long as I don't exceed 22 MPH.

Understanding that, I'm more likely to use EV mode on side streets because I don't have to be so cautious about my acceleration.