2015 prius solar roof does it drain the battery?

what else would power it if the sun isn't out? but i thought it didn't run unless the sun was out.

 

NO. And to clarify, that's a NO to either battery: 300v EV battery or the 12v systems battery.

If it's reasonably quiet outside, stand between the passenger mirror and front right tire, bend down toward the base of the windshield and hood and listen for the fan motor running. On a sunny day: a gentle purr; at night, nothing. NOTE: there is about a 10 minute delay between powering the car off and the solar fan beginning to run assuming you have this feature turned on (which must be done while the car is "on").

 

It's a very good application of solar power: the fan mainly needs to run when there's plenty of sunshine.

 

As stated above, no, it does not drain the battery.
It neither charges or discharges the 12V battery. The solar fan system only runs when the car is off, so the traction battery is totally disconnected from the car. So no effect on it either.

 

I'm still a little confused about this feature. The button is depressed on the driver side but there's no light or indication that it does anything. Do I have to actively press this button every time I want it to work or will the fan automatically kick in when parked in the sun?

 

You can see a visible difference between the button being in and out. You do not have to turn the feature on every time the car is started.

If there's sun and the function is on it'll operate automatically.

 

Thanks for the info. In the manual (and video) there's all this stuff about leaving the car on and pressing the button which is not what I expected.

 

I love my solar panel. I live in Ohio, but it makes such a difference. My '14 now has 64k miles, and of course my local shop had me test drive a new '16. Yes, it drove nice, but my I love the techie "creature features" on my '14. I will be keeping my AWESOME '14 with solar panel until the panel becomes a feature on the new model! Plus, I just got 53 mpg yesterday at highway speeds (I usually set my cruise @ 72) with the air on, jamming to enTune with Dave Matthews Band blaring away! It's a good, good life!

SM-N910V ?

 

I live in Mass and the solar panel does make a difference here too on those hot Summer days! No 5 o'clock easy bake oven for me.

 

I keep a digital thermometer in my car. Used to top out at 150 in my last car, but the hottest it's ever hit with the solar panel is 105! Love that thing... Even though those without it call it a gimmick! Don't know what they are talking about!

SM-N910V ?

 

No not true. That's just according to the manual but in reality is not. Countless times I've turned on that button with my car off and at exactly 10 minutes after the fans start blowing.

I should know. I stay in my car every day during lunch hour.