Confused: Why does estimated EV miles keep dropping?

Welcome back, Den! Still doing the double posting I see. 75 mpg? There's a guy here getting 53 mpg.
Help - Mileage Sucks | PriusChat
Consider yourself lucky.

I wish I had built the Chevy Volt too.

 

i wish i had built the batmobile.

 

What were your expectations?

Were you aware that the estimate would drop as the temperature outside did?

75 MPG real-world average is right on the money for what those of us who had driven the early model anticipated.

 

My EV range is down to 11.4 miles, probably due to the use of heated seats. However, my MPG is up -- 118 this tank (700 miles so far) because I have not been going far in the weekends. My lifetime is 90 MPG (electricity ignored) or about 70 MPGe with electricity included.

 

My estimated EV range is down to 10.2 from a high of 13.4 while my estimated mileage has increased to 180 mpg for December versus 114 mpg in October.

 

sweet! what is estimated mileage?

 

I think he meant the figures from the MONTHLY FUEL CONSUMP. RECORD screen. Those are actual, not estimate.

Here is mine:

 

Hey Den,
I am afraid you would be disappointed with the Volt as well if your expectations were that you would not loose EV range in cold weather.
In my experience with plug in vehicles, you can typically expect to loose 20-30% EV range in winter months (in the snowy northern states).

Forgive me if I missed it, but have you read people's comments about the EV range being an estimate and asking what EV range you are actually getting?
There are a number of people that can help you maximize your winter EV range, if you are willing to listen.

 

I think OP reads every one of our posts. He even replies to each individual post. So I know he listens. However, he's either not understanding or does not believe in what we wrote. That's why the later pages have degraded into sarcasm.

 

I have the same problem Den, I have over 8,000 miles on my PiP. My conditions are the same, my driving style is the same, my commute is the same, the amount of traffic is the same always, I'm an engineer with an engineer mind, who keeps a log on my iPhone notepad for every vehicle I own everytime I fill up, (A8L, S4 Stasis, Q7 TDI, and PiP base)
I now only drive the PiP to work as it is my commuter, so nothing changes, there is no variation - I take the same roads to the freeway, I take the same freeway, people behind me make it impossible to use EV while on the freeway as 62 MPH will have them running you off the road. I'm not a new owner. These self-proclaimed experts keep saying it's driving style, conditions, weather, traffic, elevation grade, but mine has done nothing but go down even given the same commute. For 2 months it was 11.1 down to 10.9 then it hung at 10.9 for 3 weeks, then it went to 10.5, to 10.1 in another two weeks and stayed there for 2 months, then for 3 months it stayed at 9.6, and now it's 9.2 to 9.1, nothing has changed in my commute. My wheels are the same 18" Enkei Rajins, on Continental DWS 215/40, with the same air pressure. My ride height with my TEIN Street Advanced Coilovers has not changed, everything feels the same.
I truly think that these self-proclaimed non newbies of the PiP actually have gotten lucky with better Li-Ion batteries. If you see my pictures you will see that when I say I have over $40,000.00 in RC helicopters, it's no exaggeration. I've learned about hi-powered Lithium Polymer battery technology from this hobby since it exploded on the RC scene around 2006 - 2007. We were paying 400 dollars per pack for a 6S, 3000 mAh, 30 C battery from high end companies such as Thunder Power. As they have evolved, the average battery for our 90 sized helis are 6S, 5000 mAh, 50C batteries. I have spent over $20,000.00 in Lithium Polymer batteries which utilizes the same principles as the Lithium-Ion battery in your PiP. My point is while all packs are good and usable, they are not black and white. There will be some that perform better than others. I can line up 10 of the same Lithium Polymer batteries, break them in the same way, fly them (discharge) the exact same minutes flying the exact same 3D stunt maneuvers, check to make sure each and every cell was discharged at no less than 3.3V. I usually take them down to no less than 3.7V with a 5 min hard core flight, and out of the 10 identical batteries, there has been some that do not last and some that keep performing at their peak. Even after 150 cycles I have batteries that perform like they are brand new and I have some that only after 30 cycles are much weaker in performance. And these are the same packs, same manufacturer, same specs. This is the way Lithium technology is. This goes beyond EV range and driving efficiently. Yes I know how to drive efficiently despite also owning a 410 HP Audi S4 Stasis. It has NOTHING to do with driving efficiency. It does have everything to do with "past driving style" when you have a great battery. It just so happens I picked a PiP that has just a "good" battery. And why would Toyota replace a "good" battery? Too bad Honda does not make this PiP. Before I traded my Civic Hybrid in, they gave me a new NiMH hybrid battery with no codes going off, nothing wrong with the old one, other than sometimes it would drop to 1 bar from 4 or 5 bars, then pick back up again. And another top of the line Accord I used to own had a V6 transmission that slipped before 100,000 miles, so Honda calls it "goodwill" they gave me a $5500.00 transmission shipped from Japan for FREE. IMO (from experience) Honda is better at stuff like this. I haven't even complained about my PiP Li-Ion tracking battery yet, but from what I can see it's not even worth my time to complain. Toyota is not very gracious in these matters.

 

That's exactly how an estimate would fall. Starting with a default value too high for actual conditions, you'll see it gradually decrease over time.

Knowing what the SOC actually is will help reveal the real story. Combine that with kWh and you've got yourself some compelling info to work with.

For those absolutely insisting something is wrong or different, I suggest purchasing a ODB-II reader and a Kill-A-Watt. Then tell us what those numbers indicate over time.

 

I'll have to find it but even Toyota has a memo you can get through your Toyota service department that says the batteries top life will decrease and this is perfectly normal. Isn't all our EV only range at the top? I never said anything was wrong with mine. Like I said I have a good battery whereas you and others got lucky with a great one.

[re: " That's exactly how an estimate would fall. Starting with a default value too high for actual conditions, you'll see it gradually decrease over time. " ]

Mine was not that gradual it stayed at 9.6 for the longest time, months... and nothing had changed, it's like Bill Murray in "Groundhog Day." Same thing over and over and now it stays at 9.1 because that is all I get now even driving granny style - (and I know it's not just about driving slow) I know how to drive effectively... I used to get 12.1 (actual) even when it only read 9.6 EV range. I was still able to average 10.5 to 12.1 actual EV miles to the tenth of a mile.

 

Unless you are reliving a "Groundhog Day," it is impossible to replicate the exact conditions on your commute. Wind, temperature, precipitation, traffic, and your foot cannot be exactly the same everyday. It just isn't possible. You are right about one thing though, it has nothing to do with driving efficiency. It has everything to with driving consistency. Which is physically impossible unless you go on a dyno inside a controlled environment as the EPA does.

If you can't agree with this fact from a self proclaimed PiP newbie, then, you'll just have to remain upset at your dwindling range. The PiP is my first hybrid and I've only owned it 3 months. I know little about electricity and batteries. What I do know is that you cannot control weather or traffic conditions. Those two are the biggest factors that will vary on your commute. And it is a known fact that low temperatures and precipitation in winter months lead to lower fuel economy whether you have an EV or ICE. Again, it is not possible for your commute to be exactly the same as it was last month.

 

I want to repeat what John said. Don't look at the estimated number of miles, look at the actual electrons going in and out. Look at the SOC as reported by the OBD system and look at the amount of electricity it takes to get a full charge, as measured by a killawatt or some other measurement tool.
Btw, do you have a laptop? Do you ever look at the "time remaining" on your battery? I never do, and the first thing I do on a new computer is to change the display to show percentage instead. Because I know that any sort of time estimate will be pretty useless.
If Toyota is reading these forums, I'd think it would be very wise for them to eliminate the mile estimate in gen 4. It should just show a percentage.

 

i'm sure it's true that not all battery packs are exactly the same, but i'll bet they are close enough that you couldn't tell the difference without the proper instrumentation. mine started at 13.3, went up to 16.7 and is now down to 12.6. it's frustrating, and you want to blame someone, but i'm attributing it to cooler weather and hoping it bounces back next spring. if not, that will be a whole 'nuther discussion.

 

"whone?" "nuther?" "probably?"

 

Remember, I already had a taste of winter with my PHV back in March. I witnessed firsthand the increase in capacity associated with warmer temperatures... then saw the drop again as it got colder.

 

bisco bonics.

 

Moviebizman, if you are an engineer, you should recognize that there are variable than have charged over that time period.
What was the average outside temperature when you first bought the car and now? I am guessing it has changed.

Now, it is perfectly possible that there is something wrong with the battery pack. However, there are other much more likely explanations for the change in estimated range.

One is, that the original range does not represent your driving patterns/habits. So the car will automatically adjust to your driving patterns.
Another is weather, temperature changes, humidity and wind direction and speed will all affect air density, rolling resistance or aerodynamics.

And yes, over time the range will decrease. But given the lack of deep cycles (I believe Toyota doesn't even allow you to use the top or bottom of the battery) I would be shocked if it was more than 2% a year and likely much less than that.

 

Owners are going to continue to be concerned that their battery is experiencing an early demise until there is some method to confirm that it is healthy. Perhaps gen 4 could include a "battery cycle" diagnostic routine that confirms that the battery is able to be charged, discharged, and produce the kWh at a rate within the original design parameters. running the cycle every 4-6 weeks, while plugged in and with 65-75 degrees Fahrenheit temperatures should help detect any problems and relieve most concerns.