solar roof

A simple test is to take the temperature with and without the solar fan on on a Similar day on the rear seats.

This moderator Who lives in Arizona noticed a 15 degrees lower temperature. Others in a old thread reported up to 25.

Arizona can get brutal hot in the summer, where I live the temperature in the summer is high 70's but can reach 80's a few days a year

2010 Solar Roof Temperature Report | PriusChat

 

Have you noticed debris getting stuck in between the glass roof and the sliding shade? I park near a lot of trees/shrubs and I find a lot of stuff stuck in there, so I just leave my sunroof closed.

 

It does help some why it could not recharge the battery i don't know but it should.............

 

Not nought output to charge battery

 

There is enough output to keep the 12V battery charged (40W at 15V is over 2 Amps), BUT - it uses a switching regulator with poor filtering. Rather than have to deal with the noise messing with the computers in the car I suspect Toyota decided to just let it do the one job. Maybe the GIV will also keep the 12V system fully charged.

 

Im curious, what would be the benefit of charging the 12v battery? It would be cool if it charges the hybrid battery.

 

I'd guess that it would give you enough energy to go 100 feet. Uselessly small amount of energy.

 

It would. Alas, reality intrudes. A solar module that size might be able to manage 14-18 Volts (and thus able to charge a 12V battery), but in order to charge the hybrid battery, it would need to be 200V, just not feasible (200V would need 130 cells). Also, there just isn't much power there, it wouldn't even be noticeable in the big battery.

The solar panel might be able to keep the 12V topped up, there is a small draw on the battery at all times, and this would help alleviate that when the car is sitting unused for long periods.

 

As much as I like the views from the sunroof, I agree that I wouldn't buy it if it didn't have the solar panel.

 

Some on here don't realize -most- if not all cars will have a dead battery in about a month if left parked and unused. It's not just the Prius. So as surmised above, the solar panel -could- keep the 12V battery charged,
-IF it's parked in the sun, and
-IF it's sunny or bright enough, and
-IF the panel isn't covered with snow!
As I posted above, I suspect that with that many ifs along with other things more important to work on Toyota didn't bother to hook it up. It actually wouldn't be that difficult, though you WOULD need a "special regulator" to avoid overcharging and loosing water in the battery even faster than it does now.

 

So quick question, the Solar Panel charges only the battery for the solar fan? The Remote AC does it just run off the 12v battery? For some reason I thought the AC was running off of the Solar Panel.

Thanks!

 

Actually as I recall the solar panel runs the ventilation fan directly, there's no intermediate battery involved. You don't have to store up charge to run the ventilation fan when it's cloudy or at night because then you wouldn't need to run the vent fan anyway.

The remote AC runs off the traction battery as I recall, the 12V battery isn't big enough for that.

 

There is another very important reason the panel doesn't charge the traction battery. If it did it would require a complex (read expensive) charging system. It would have to tell the battery computer how much charge it put in. It would have to stop when the battery got close to 80% charge. It is possible to use a switching regulator to convert from 12V to 250V (the voltage needed to charge the traction battery) but the charge control and computer control would be expensive. And as mentioned above, it wouldn't put much charge in that battery. For example, if the fan was off because the temperature was too low you would have full power to charge the traction battery. The traction battery can contain about 680 W-Hrs of deliverable power (that's to 30% charge from 80% charge, the range it operates over). The solar panel could deliver about 35 W-Hrs to the battery in optimum conditions. You could expect optimum conditions for perhaps 3-4 hrs per day. That would be enough power to drive a kilometer or two. Is that worth the cost? Remember, this would probably shorten battery life noticeably, and the extra electronics would probably increase the cost of the car $200 to $500.

Any system would also be operating at high DC voltage. That would put more dangerous stuff in the car that emergency and service personnel would have to deal with. The way the car sits now, when off, the high voltage systems are completely isolated to the traction battery case.

Keeping the 12V battery charged would be much less expensive. Perhaps $50 for a better switching regulator with built in charge regulation. It might lengthen the 12V batteries life, if it were limited by discharge events. It isn't. It's limited by water loss, and this would increase that.

So there are at least three reasons to not charge either battery with the panel.