EV mode warm up

Welcome, Aldo.

EV range is always an approximation based on state of charge, temperature, driving habits, and stuff like that. If you check the actual state of charge with something like Dr. Prius, Torque Pro, or OBD Fusion, I suspect the real SOC would be almost exactly the same in the morning as it was the previous night. What changed was the temperature and possibly the way you drove the day before.

The EV range displayed does not tell you the state of charge. Most of us call that display the GOM (Guess-O-Meter). I keep mine set to percent charge and, if I want to see the range estimate, it's just a couple presses away with my left thumb on the trip meter button. (Or the right thumb on the up or down button to see it with & w/o HVAC.)

 

What @jerrymildred said. GoM (Guess-O-Meter) was estimating the remaining range based on the way you were driving days before. But that estimation is rarely accurate to begin with. You could have used up 2.5 miles of estimated range in less than 1 mile of driving depending on various factors such as driving technique, quick acceleration, uphill grade, low or high temperature, use of HVAC, etc. In general, starting from a park to get to speed will take more energy than coasting.

That being said, you do raise an interesting point. Although I have not read any thread discussing the cold start affecting the EV efficiency, it is conceivable that battery and/or motors are more efficient after the initial "warm-up" period.

The fact you notice this effect only when a small amount of battery SoC (State of Charge) is remaining is but not when its full is probably due to the margin of error. GoM constantly adjusts the remaining EV range as you drive. If you start with a full battery, starting ~25 miles or more of range adjusting a few miles less is not very noticeable, but starting with only 2.5 miles range, a few miles less is very obvious.

 

the range algorithm based on previous driving wouldn't change as the car sits overnight. nor would a change in ambient air temp. i see some cause for concern and investigation here, but not panic.

if it doesn't change with a full charge, i see no reason why it would change with a partial charge.
i agree with above, get an app that can show you real data.

 

I don't think OP is saying the GOM changed the remaining EV range from 2.5 miles to 1 miles after overnight parking. I think what OP is saying is 2.5 miles EV range indicated on GOM was used up within 1 mile of driving following day after staring the car. This is perfectly normal. It happens to my PRIME all the time. GOM EV range is never 100% accurate except when it indicate 0 EV mile. It adjust more drastically as the traction battery nears 0% SoC than when it is full.

 

thanks, i completely misread that

 

You should not be looking at the GoM range for EV efficiency. The range indicated on the GoM changes vastly as you drive. I can have 8 miles left on my GoM EV range at 6 miles before reaching my home, but usually, I do not get home all on EV. EV usually depletes a few miles before reaching home. My daily commute distance is ~36 miles and during summer I can get 32-34miles EV range from a full charge. GoM usually gives optimistic estimation, but as it reaches close to 0% SoC, it rapidly adjusts the EV range so that it is always 100% accurate when SoC reaches 0%. In your case, driving home on a highway and driving off from your driveway after it has parked overnight are totally different driving situations for the same few miles.

 

for some reaso, when you are trying to eek out final distance to a destination with a similar amout of gom range, it always disappears faster than actual miles driven. even at slow speeds on flat roads with no hvac.

that being said, 2.5 miles gone over 1/2 mile of slow driving would be unthinkable in my pip

 

Even when just starting out? EVERY time I start a drive, that first mile on my MID display of m/kWh shows about 2-3 miles per kWh. The rest will be closer to five or even over five. That first mile sucks down a bunch of electrons since you are accelerating more than decelerating in that first mile. After that it more-or-less evens out with equal-ish acceleration and regeneration.

To repeat, the GOM is a big fat liar. Measure the actual state of charge. You SHOULD find that it's the same in the morning as when you parked it the night before and you'll also see it drop in a big hurry for that first mile or first few minutes as you get up to speed.

 

I've noticed that the actual state of charge (indicated by hybrid assistant) can change overnight, especially if it's at the low end and/or if there is a significant temperature change from the day before.

You can set the MID to display the usable charge as a percentage. It goes from 0-100%. It's better than looking at the number of miles remaining, but it's not perfect. Parked overnight, the car will rarely update the percentage it indicates, but sometimes the actual state of charge will change.

The state of charge indicated by an app like hybrid assistant will go from about 8% to about 87%, because the full capacity of the battery isn't used.

I get the best efficiency when the battery is hot (it usually stays right around 95F all summer). If it cools off significantly overnight, there might suddenly be less usable range when you start driving. The car doesn't indicate that, maybe because they want to keep up the illusion that the charge remaining doesn't fluctuate.

In the first mile of EV driving, it barely warms up in terms of actual temperature, but it does get the display to catch up to where the battery really is.

 

yes, mine is remarkably accurate. was your pip the same as your prime?

 

Your estimated range? No, mine was never accurate because my driving was and is too variable. One day I might be on 35 mpg streets for most of the drive and the next day might be 60 mph with a red light about every mile. The poor thing never knew what to expect. Same with the Prime but more so since it's over a longer distance and has more opportunity for variations. But it's generally within a couple miles starting from full.

Edit to add an example. Yesterday I went to an all day meeting a little over 8 miles from home. Going over there in the morning, I averaged 6.8 m/kWh. Coming home in 93F weather with heavier traffic that forced me to drive more like the clowns around me, brought the average for the day down to 5.2, which would be 3.6 m/kWh on the way home. How can the GOM predict anything like an accurate estimate with that kind of variation?

 

not the estimated range, just the problem the o/p exhibits. if i go out first thing with 2.5m estimated, i'll get 2.5 miles plus, unless it is an unusual circumstance of high speed, accelleration, or full a/c, etc.

 

I've never done that. Always had more charge than that when leaving in the morning.