Declining EV every day after full charge??

A similar situation occurs when many new Prius owners encounter VSC and other braking interactions. They often describe their Prius as having "accelerated wildly" while braking when going over a wet metal railroad crossing. When many PC responding posters provide an explanation the OP responses are all over the place. After a while it becomes clear that some really just want support in their "crusade" against the dealer or Toyota for a defective vehicle.

If I remember (or maybe I'm making this up) there was a poster a long time ago who was complaining bitterly about how his Prius mileage was nowhere close to what everyone claimed he should get. Somewhere much later he made a side comment about how the Prius was also a dog at towing his boat at the same time.

 

I get the impression you were hoping for an all-electric experience for 15 miles, unaware of the factors which reduce range and not interested in the resulting MPG.

Getting a return of +75 MPG is quite acccptable for many. What were your expectations?

 

I think Suzy has a very ignorant dealer that stressed the "15" mile range without the "Up to" part! That and the 13.9 computer estimate that was showing when she bought the car led to high expectations. A 10 to 11 mile range seems to be the norm, so she's off by a mile or two due to the hills and hauling around her kids and stuff. In any case she's not happy with the car and that's completly understandable. I'm sure a Chevy dealer will love to give her a good trade in on a Volt!

 

I drive on the slow side. Lots of short trips to the market, Home Depot, etc. on EV only. What probably increases my projected EV miles (last week as high as 18.2; this week in the 17.5 range) is the heat (Southern California) and a 60 mile drive I take twice a week. The first half is generally uphill and the last half generally downhill. I use HV going up, and set the cruise control to 60 and use EV going down, so for long periods of time the ICE is off. I travel in the right lane of a 4 lane freeway with lots of trucks. Usually some are going about my speed of 60 (the maximum speed limit for trucks is 55) but many do pass me. I am retired an in no hurry, but do not want to hold up other traffic.
I believe trying to achieve high projected EV miles is only a game. Whenever I try to measure actual EV miles traveled, it is much lower, in the 11 - 12 range.

 

Hello Susie, My driving pattern is identical to Craigcsj, with a couple of exceptions, I attempt to arrive home with zero miles, controlling this with some use of HV. I believe this greater requirement of charge produces a better charge. I initially started out with 12.2 and now have 14.8, none of these readings are ever consistent. Perhaps a characteristic of the lithium-ion battery. Another possibility is to look at the charging cord itself, 110 volts in = 110v out, any electrician can do that. Toyota may/should lend you another cord for a week or so. Another item, look at your total EV mileage after a trip. This requires a bit of forethought, Before a trip reset the trip guage, at any point in time add your trip to the EV miles still showing. This represents your total actual EV MILES ( at that moment ) To further increase your EV distance, switch to EV on every downhill and good rolling flat. Do not use CC, This defeats mileage This portion is impossible to figure out without a stopwatch and calculating percentages. Roughly I have accomplished 25 miles using this method ( primarily EV ) My overall results on both trip guages is now 88 MPG, I consider that pretty good. GOOD LUCK.

 

My EV range dropped from 13.9 when new to a low of 10.3. My driving pattern was to start out in EV mode and just let it run that way until it ran out of EV range. My commute to work involves several decent sized hills that I have to go up. As a result, I would run out of EV range long before I had traveled those 13.9 miles. Sometimes when going up those hills, the car would switch back and forth between EV-only and blended mode (running the gas engine as a boost to the electric motor). A ScanGauge II showed I was pulling a lot of amps out of the battery in either mode.

When I hit that low of 10.3 miles, I got worried that my battery was defective. So I modified my behavior to test a theory. I started using the EV/HV button. When going up those two hills now, I manually put it in HV mode. When I know I'm going to be going at 62+ MPH for an extended time I switch to HV mode, saving the EV miles for when I got back to surface streets, or when in slower traffic on the highway. The estimate is now creeping back up. It's at 10.8 now. It's not a huge improvement, but it does tend to lead me to believe that my theory is correct.

What you should be more concerned about is what sort of gas mileage you are getting. I'd be more worried if I was getting crappy gas mileage and my EV estimate was low as well. That to me would indicate a bad battery.

 

Am I wrong but anyone with a PIP will greatly improve their gas mileage if near the end of the trip they make sure the ICE is not on through use of much slower pedal pressing and use of tapping the brake to kill the ICE. Because the car wants to keep the HV battery above a certain level, you could try to mostly drain the HV battery just before you get home and then the plug in overnight will basically mean you are using electricity instead of gas to replace that lost SOC.

Anyways just doing that might improve gas mileage a lot for people that don't drive far daily.

 

alls i can say to this is that it's all perfectly normal... you'd be very surprised how much of a difference a small grade can make in battery consumption. my home is at roughly 300 feet above sea level. if i drive down to the bay on surface streets (~280ft elevation change), i can go 4 miles on just about 440wh, or an astounding 110wh/mile. coming back up the hill i measured the consumption at about 370wh/mile. to put this in perspective, on a full battery i could go 25 miles on the downhill path and 7.5 miles on the uphill path.

granted i did this once, and the traffic lights could have been different going vs. coming. but it gives some indication of how much coasting can add to the range.

i have a loop that i've been making recently which is about 11.1 miles long. i have to go from 300' up to about 700', up and down a few times, back down to about 50' and back up to 300' again. most of this route is freeway miles. if i really baby it, drive under 62mph, and am careful not to put my foot in it too hard, i can actually make this whole trip on electric alone, though more commonly the ICE kicks in somewhere along the way.

when i start the car these days, it tells me 10.1 miles on a full battery.

 

That is a great response to the impact of elevation changes. What app are you using to measure the elevation?

 

It would be interesting to measure, say via OBDII, the regen gains and actual battery SOC.

(For comparison I just did some measurements on the Volt for this and in a 300ft elevation drop over just 1mile produces a net gain was about .35kw of power via regen. so -350wh/mile ;-) One of my best yet.

 

this is not necessary, the pip has an hv/ev switch that let's you toggle back and forth between ice and battery.

 

rats! i really really really wanted your pip. i'm sure you misunderstood my post, i was replying to drino.

 

just google maps. the trip was between my home and an office on the border between oakland and emeryville the other day. i just looked at the topo map in google maps to get an idea for the elevations.

well, i was using the OBDII port and my scangauge. the car started the first leg of the trip at 85% SOC and ended at 75%. with a 4.4kwh total capacity, that's 440wh right there.

there's got to be a significant amount of regen in there, but since i don't have any way to record the data, and i can't stare at the gauge while i'm driving, i cant say how many times the SOC went up and by how much.

one flaw in my data is that i may not have rebooted the car at the end of the trip. since the SOC is only the computer's guess as long as the car is powered up, i've seen the reported SOC and the actual open-circuit SOC differ by a couple of percentage points.

i have an old logger app that Ken@Japan developed in the days of the gen-II prius. i should hook that up and see if it can parse the PIP OBDII data. of course, i don't know where i put my OBDII to serial converter thing...

 

We often have some fascinating discussions on PC, That is why I enjoy participating. But when we have a newbie and ask specific questions on modes, symptoms and make suggestions we often get NO response or a misinterpretation of our sense of humor. It appears as tho this is where this thread is going. It is really a shame as all of the PCers are truly interested, as they also pick up useful information. Without concrete feedback the thread becomes irrelevant!

 

175 MPG !

 

You can get infinite MPG, just only drive 8 or 10 miles each day. The discussion of MPG is meaningless with plugin unless you are giving an equivalent cost for the electricity in gallons of gas you could have bought (unless you live on a solar farm), and you need to take into account terrain and miles driven per day. You could live at the bottom of a hill with a PIP and claim stupid insane mpg because it is all plugin charge leaving and all downhill returning.

Convert the electricity you pay for each day into equivalent gallons of gas.

A prius charging station is (16A, 3.8kW output)
gas prices and equivalent kW and price of kWh
you can use $0.15 per kWh, let's say $3.50/gallon for gas, and 1 gallon = 33.4kWh

So if your charging station can pump in five hours of charge so say you put 20kW on to the battery (I don't know what the typical PIP battery SOC before/after is) then you saved from buying 0.6 gallons of gas the next day, so you saved $2.10 in gas, but it cost you $3 in electricity.

PIP only make sense depending on your current electricity prices and the current cost of gasoline per gallon, otherwise you are better off not plugging it in. And when it is cheaper for the electricity prices you are better of making sure when you get home the HV battery SOC is down to as low as you can get it. (Which means you are exchanging the battery lifetime for saving a few bucks, which is ok if Toyota is going to replace your HV battery for you, otherwise it doesn't make sense to get home with 40% SOC and charge it back up to 80% every day, cutting the battery life in half probably).

Plug in hybrid cars are really dumb unless gas prices go way up, or you get cheap electricity, or maybe you get your power from solar and hydro and you care about the environment. They never make economical sense unless someone else is picking up the tab for a new HV battery pack.