Is My 2025 Solar Charger Malfunctioning?

is there are charge percentage on the car screen as well? if so, does it match the app?

 

It doesn't make sense to assign that solar charge to the initial part of the drive - where there's maximum power draw with you getting up to speed and stabilising the climate, and then conclude you're not getting value.

It would make more sense to look at your 20.8 miles on 40% and conclude you got 3/40 of 20.8 = 1.6 miles.

 

3/40 or 7.5% of 20.8 miles.is 1.6 miles. Don't start getting other percentages muddled with your percentage of SoC.

And the electric usage varies massively. Haven't you looked at the efficiency trip view?

Maybe it's less clear when using miles per kWh, but when looking at kWh/100km, you'll have some one-minute bars down at 6 and some hitting the display limit at 40.

One acceleration to motorway speed.can consume the same as a couple of miles of slower cruise. So sure '2.5 miles' of charge can easily be used in half a mile.

Over the long run it all averages out, but you're looking at a real micro level here with these tiny charge deltas.

 

is there anything in the o/m explaing the battery percentage?

 

Your car's sensor is probably reading the surface charge on the traction battery and yielding the 2.3 mile distance calculation. This is similar to taking a battery off a battery charger. If you take an immediate reading your going to get a higher voltage than waiting 15 minutes for the battery to "settle". Garbage in; Garbage out..... and a better reason for the 0.5 mile actual gain. Have you done the actual math; isolating the panel output and tried comparing it to the car's readout????

 

Yes ...

p. 156 calls that percentage item in the MID meter display the "EV energy remaining" with the added definition "Displays the amount of charge remaining in the traction battery".

Just did a real-time check on my own vehicle:

MID display = 57% (2:44 PM)
Toyota App = 59% (App updated at 2:44 PM)

And interrogating my CAN bus with an OBD2 scanner using three apps it seems related to the State Of Charge (SOC):

Dr. Prius = SOC = 56%
OBD Fusion - SOC = 56%
Car Scanner Pro - SOC = 56%

And while my OBD2 scans gives me way more precision and split second SOC values to multiple decimal places, the Toyota vehicle and app offers no decimal place.

So 57% can mean 56.5% to 57.499%.

This isn't about a percent here or there is it? Oh wait, maybe it has been all along.

 

too bad it doesn't report kwh instead of miles. miles are just a guesstimate based on remaining kwh and past miles/kwh formula

 

Toyota does provide the solar watt-hour gain for the current day and kWh all-time (unless cleared). Divide that watt-hour by 1000 and you got the kWh (Something demonstrated in post #11). So it's there if that's what you want to use otherwise they do some conversion without any given formula to come up with miles and show that too.

Not unlike a public trail I walk where they post signs along the way like "Congratulations you've earned a cheeseburger by making it this far".

 

I've had my solar Prius for 10 months now. Your solar roof is working fine by what you've posted, but trying to get exact conversion of percentages to miles is a waste of time and sanity. You can do all the math you like but it doesn't change the fact that the mileage estimate is a computer's best guess, nothing more. A/C, heat, hills, speed, etc all impact it. I have gotten everything from 0 to 5 miles in a day (that last one has only happened very rarely), I do notice more electric range when its sunny, but exact miles to percentages is all over. So I wouldn't panic, it clearly is working, but trying to do fine grain detail in any system with as many environmental variables as a moving car is just a great way to go nuts. On average, I get roughly 50 miles a month by my own measurements from sun, give or take. Not anywhere near the hypothetical maximum. But still a free 'gallon of gas' a month or so!

One thing that I myself wondered about was that I've seen the wattage go OVER 185 when driving in totally clear weather, the estimate was nearly 200 breifly. That surprised me, at first I thought something was wrong but others have reported the same. Jury is still out on the cause/meaning.

 

I did an exactly two-hour test for you with my vehicle:

MID display for solar showed "Power Generated" of 1.0 mile "Since Vehicle Turned OFF"
MID display of battery percentage which Toyota calls "EV Energy Remaining" went up from 28% to 29%
Multimedia Vehicle>Solar>Energy showed "Power Generated" of 244wH over the two hours.

OBD2 data taken at start and end showed Hybrid Battery State of Charge (SOC) went up from 36.47% to 38.43% (1.96%).

Napkin math using actual electrical energy numbers (not percentages):

With a nice round 10kWh of energy reserved by the vehicle for EV only use (it's actually higher) that 244wH provided a gain of 2.44%.

Therefore, if one achieves 4.5 miles per kWh then 2.44% of that would be 1.1 miles of added range which nicely matches with the MID "Power Generated" figure of 1.0 miles (which I can only dream Toyota adjusted downward to include known losses).

So, remains the case that using "EV Energy Remaining" percentage would not be advised for the solar math.