No, It’s Real: EV Range Down

You can roughly estimate it by seeing estimated range (climate off)/ estimated miles/kWh when you’re fully charge. All the info you need for that is in the middle page of the screen to right of the speedo.

 

garage won't help much. the estimate is based on past driving, and actual ev range will be determined by driving environment, not charging environment.

 

I have noticed though that my car will say it’ll take 2hr and 20 minutes to charge, but when I come back 1 hour and 30 minutes later it’ll say 10 minutes left. Temperatures are pretty temperate in California too, so I do think charging times offer a clue about capacity.

 

absolutely.
funny though, even though i have lost roughly 15% range, my pip still takes 90 minutes to charge

 

So, I’ve dropped from a monthly average of 4.7 miles per kw to 4.0. The cold weather would account for that. However, it doesn’t account for the entire 8 mile per charge drop in range.

 

Yeah, .7*6 is about 4 miles so there's another 4 miles missing somewhere.

 

miles per kw are affected by driving in the cold. with the same battery power, you would lose to air and road friction on a clear day, more in weather, and the battery/inverter/motors are less efficient

 

If somebody is losing miles per kWh, that's not a loss of battery capacity. You could lose 90% of your battery capacity and still you would get the same distance on that last 0.6 kWh as you would on 0.6 kWh when the battery was new. The telltale sign of battery capacity loss is the miles per kWh remaining relatively constant and the EV miles decreasing.

 

Both appear to be happening in my case. The cold accounts for the loss of miles per kWh, but there is more range loss than can be attributable to that alone. The decreased time to charge (approximately 1 hour less from 0 to “full”) is what concerns me most.
The manual says extreme cold or heat can cause the battery to accept less of a charge but still read full. However, the cold here has not yet reached what I would consider extreme, and I always charge in the garage. The manual also says if this happens without extreme cold or heat to take it to the dealer. Since my dealer has zero knowledge about the Prime, I came here first for advice.

 

and you are getting it.

trust me, i've been doing this for 6 1/2 years. range starts drooping in the fall when temps start drooping below 70f.
right now, i'm down 30% from my summer high, and it has done this from the first winter i had it.

i have always charged in an attached garage. this morning was 15f outside, and 42f in the garage.

you do have an advantage with battery conditioning though, pip does not have that. is it turned on?

 

and if you're using any heat, that really eats up the battery

check your tires pressure as well, they drop with the cold

 

I had an 09 Prius and can attest to the dramatic drop in mpg from warm to cold - it was shocking!
I have not tried the conditioning. The car has been finishing its charging a full hour prior to the scheduled time - will conditioning still only happen just in time for departure?

 

if you are using departure time setting, i can only assume that it will. but a check of the manual, or test on a day when you don't have to leave would be a good idea.

 

I have been quite miserly with heat - only using it to defog when necessary by directing heat to feet & windhield, not using the defroster. I use the seat & steering wheel heaters, since they are less of a draw. I know my snow tires take a toll as well, and I keep them well-inflated. I would think all those factors show up in miles/kWh.

Your 30% figure makes me feel a bit better - that’s about my experience right now. Wondering how much more this will drop, since we ain’t seen nothin’ yet in my neck of the woods.

 

I've tried conditioning for the past few days. It adds about 15 minutes to the time, so now it's done charging about 45 minutes before departure. The conditioning appears to happen at the end of the charge cycle, even if it is early. I used my app to turn on the heat in the car 10 minutes prior to departure, but this drained a bit out of the battery, so the car started charging again since it was prior to the departure time. Because I had to leave, I wound up with less estimated miles.
I think I will just ignore the poorer EV range until the spring thaw (sometime in May 'round here). If it's still substantially reduced from last year, I will be more concerned - not that there's anything Toyota will do about it. In the meantime, I will just switch to HV mode on the highway, enjoy some heat in the cabin, and reserve the EV miles for the city portions of my commute. Even with the reduced range and the typical winter hit on mpg, I am way ahead of where I was with my 2009 Prius Touring, which struggled to achieve 40 mpg in the winter months.

 

oh, that's way too sensible!

 

Let’s see if I can stick to the plan

 

On the other hand, I forgo the cabin comfort and drive to work in the cold. I just alternate sitting on my hands to keep them warm (can't find my gloves). It's kinda funny when I get to work, where it's 15 - 20 degrees warmer. The inside of my car is still the temperature it was when I left the house so it feel like opening a refrigerator.

 

Heated steering wheel - never thought I’d use it, but it’s perfect for those days when you realize you left your gloves at work