Solar Charging Roof Not Working!

It may be that the shorter daytime hours are causing the negative effect as we approach winter solstice. Between that & the way many car's parasitic loss can drain a system, a solar panel just allows a break even effect

 

^ That and you can't point that panel into the sun. The shorter daylight hours and sun's lower angle is going to greatly impact that array's output. It's supposed to be a 200W array and people who checked output stated it only generates 180W at high noon - assuming that's the best your going to get, you still need to subtract the electronics that needs to be powered to get that into the battery.
As I've stated in other post, gimmicky at best and considering electricity only cost less than $0.20/KwH, the numbers don't pencil out for that option.
The car is under warranty and it's a legitimate dealer option, so there should be a valid dealership test procedure for it.

Good Luck......

 

if it sits all day for multiple sunny days without adding any charge whatsoever, and the dealer can replicate it, they can diagnose it and repair it.

 

What's your latitude?

Is there a south-facing hill you can park on in the winter months, to try to reduce the angle difference θ between the panel's normal and the sun, so the cos θ factor in the power developed won't be as small?

 

Check that the traction battery has at least 5% SOC. It won’t work with 0% SOC or less.

Make sure that the solar panel is entirely clean and no parts of it are in the shade.

Sometimes, when it is too hot outside, like the last few days here in Southern California, the solar panel will not work due to the high-vehicle-interior-temperature protection.

There could also be a malfunction in the solar-charging system.

 

Los Angeles latitude is around 34° north. Earth tilts by around 23° (I'm gonna say, somebody could look up a more official figure).

So in late June, your noonday sun hits the panel at 34 − 23, or about 11° away from straight up (when the car is parked level). In late September, noon was 34° from straight up, and in late December it'll be 34 + 23, or 57° from straight up.

The power a panel can collect from sunlight is the power arriving in the sunlight times the cosine of that angle (then times the panel's efficiency, of course). If we pretend there's the same solar power arriving and the panel's efficiency doesn't change, then just the factor having to do with the angle varies from cos 11° ≈ 0.98 in late June, through cos 34° ≈ 0.83 in late September, to cos 57° ≈ 0.54 in late December. Around Los Angeles.

So the angle difference alone limits what you can collect in winter to a little over half what you can in summer, even before taking into account the fewer hours of sunlight.

 

Do you have window visors and keep the windows down about a quarter inch? I do that for all my cars. It lets the heat out of the interior so your pack doesn't get heat stroke. The interior cabin temperture isn't going to damage the pact, but when you start drawing current; it's going to get hotter faster. Also easier on the AC unit since it relieves some of the cabin heat build-up.

 

no one has reported any malfunctions here until yours.
the dealer and toyota are obligated to repair it by law or buy it back from you.
if the dealer can't figure it out, they work with toyota, who will send a field agent out if necessary.
don't hesitate to make an appointment and take it in, they should provide a free loaner.

 

It's fair to expect that none of the techs at a given dealership will know offhand how to take care of that, but I wouldn't worry too much: Toyota develops very good repair instructions for their techs to follow. They are relatively used to doing whatever the manual says and coming back with positive results.

 

It's a fun option if you have the money. It reminds me of the tiny solar cell I got in an electronics kit, back when I was a kid. It couldn't do anything practical, but it could move the needle on a meter. Very exciting.

 

I have the 2010 version, with a 60-watt panel. It's enough to come back to a ventilated cabin in hot weather (which was all it did, from the factory), plus (since I added a buck converter to feed the 12-volt system) prevents me worrying about coming back to a dead 12V battery if I leave the car too long.* I can even go a sunny weekend with the fridge in the car and not have to start it up for charging. (And still have a ventilated cabin, too.)

If I had the newer version with a triple-the-power, 180 watt panel, I'm sure I could think of some ways to use it.


* I added that mod during the pandemic lockdown, when I was routinely going weeks without starting the car.

 

This reminds me of the Solar Roadways debacle. No amount of facts and physics can convince some people that it's a stupid idea.

 

warranty can be done at any dealer.
dealers don't buy back lemons, manufacturers do.
you can look up cali lemon laws, but it won't likely come to that.

 

Get a BM2 battery monitor to have a clue on what is going on.

 

Post #2 introduced an idea that the collected energy may need to exceed some break-even point. If so, a sufficient reduction in collected energy might not.