2010 Solar Panels to Charge HV Battery Pack

I think this has been discussed before and the reasons explained. It's been awhile, but as I recall it has to do with the voltage output and electrical interference. Doing a search will find the right threads.

BTW, the solar panels are not used for the A/C. They just run the fan...

 

I'm not sure I buy the electrical interference reasoning. If it's rectified and filtered DC, or even in shielded wiring, any interference should be avoidable (It's not like it should have any ac or HF component, or reverse EMF from motors or relays).

But given the specs of the panel (depending on where you read it: 40-80W), even a full bright sunny 80W output will give you only (W * 0.00134 = HP) 0.107 Horsepower.

Seems small, but the traction battery capacity is roughly only (201.6V * 6.5Ah) 1310Wh (437W for 3hr rate), but only charged to 80% = 1048Wh. Pretty amazing that it can handle pulling over 3000lbs for half a mile (Newton's 1st law helps, i guess).

Max MG output is like 60,000W (80HP).
Really give you some perspective on how hard the traction battery can be worked, for instantaneous 80HP assist.

Of course, we wont be getting anywhere near 80W or 60kW, except in rare "ideal" conditions. And there are always losses in conversions.

Float the 12V battery mabye, but hardly seems worthwhile to use the solar panel to charge the assistive Traction battery

rich

 

Yeah, makes you realize just how far we have to go until solar cells are an effective way to generate electricity.

 

It is avoidable, but it can take a bit of time and resources to get it done right. At release time, it sounded like they ran into a problem, and ran out of time. Punt, try again next year.

 

Hi there,

excuse my questions, I really don't know much about these calculations but:

aren't there little green car-symbols on the multifunktion-display when I regenerate through deceleration or going downhill?

And one car-icon stands for 50Wh. My experience with the prius06 tells me that i can go at least half a mile (800 meters) in EV-mode with three of these green-symbols.
When there are six hrs. sunlight, doesn't that mean the prius would be able to regenerate about 300Wh?

And that should make close to one mile in EV-mode!

So that's not nothing, and I actually hope Toyota soon finds a solution to connect the solar roof to the traction batt.

kr
wogue

 

I'm not disputing you, but how do you correlate the regen symbols to anything as far as how far one would propel the car?

 

The 50 or 60W generation is the peak power at noon.
The average wattage will be 20W from 9AM to 3PM, then the total will be 120Wh.

Ken@Japan

 

It's relatively easy to regen 6 little cars during a 15minute drive. But it takes ideal conditions to (solar) generate that much power in a 6 hour stretch.

You may have 6 hours of sunlight, but unfortunatly, it's a bit more complicated than that. Mostly because of your location (on earth), weather, and panel aiming. If you live in a hazy area, that is cloudy 50% of the time, and your solar-panel is not perpendicular to the sun's rays... the entire time... you can see how the inefficiencies build up.

Here is a link that gives a bit more ideas and details about solar panels and tips (used it for my son's science-fair project ;-).
Solar 101
(I'm not affiliated with them in any way).

rich

 

Can the battery really output 60kW? I thought it peaked at something like 100A (20kW)... I believe the MG2 max power is achieved only when it is fed power both from the battery and the ICE through MG1...

 

Correct. MG2 can handle more power than the battery alone can deliver. As you surmise, this is because MG2 can be driven by the battery and the ICE-MG1 path.

Tom

 

The GenIII has a 27kW (max) HV battery output. Using simplified calculations at 201V that's about 134A from the battery pack. If the Battery pack is rated at 6.5Ah that's a current draw of about 20C.

It's easy now to see why the EV mode is so limited.

It would be nice to see a nice safe Li-ion/poly chemistry with a larger capacity in the prius. Hopefully the new battery chemistries or supercapacitor that have been announced recently become marketable in teh next 5-10 years.

 

I said that my prius-experience (3,5 yrs) tells me how far I aprox. can go with these symbols.
Anyway...
Well after someone wrote about 40-80 W coming from the solar roof, I just picked 50 W, but you're right: we don't know how much Ws reach the battery and can be stored there.

kr
W.

 

It seems like there should just be an option for this "fan" setting on non-solar cars. A fan runs maybe 20W.......

 

Just to reaffirm what many are saying, I feel that there is just so much potential that isn't captured in the G3 Prius. Yes, in Houston MOST of the time a little fan to swirl about the air isn't unappreciated, though when it isn't that hot (for all 5 days of the year!) and in other places where you don't necessarily NEED the fan circulating the air, it would be nice to charge the traction battery to its limit. Even if it only charges it 5-10% during the day, thats 5-10% that is otherwise currently being lost. My 2010 is rarely below 2-3 bars to full when I park, and if it could get to "full" (which is apparently only really 80% full) that would be that much farther you could get before the ICE needs to kick in.

Far stretch I know, but I've heard people rigging a solar panel to the 12v ACC battery, would this help anything in the least?

 

Yes, I would be interested in having an option/switch for the solar panel trickle charge the 12v auxiliary battery instead. This is particularly useful if I can park by car under direct sunlight and go away for 1 month+ holiday without having to worry about the 12v dying. Coming back home to drive a dead Prius in the carpark is embarrassing! Some engineers here give us that options please!!

 

Here we go again!

1. You DON'T want to dump any more power into the traction battery than the HSD currently generates! If you do you will operate the batteries closer to their maximum charge. This is a "bad thing" (tm) as it runs the risk of overcharging the lowest capacity cell, possibly causing it to loose electrolyte.

2. The amount of power the solar panel generates is tiny compared to the power needed to actually -move- the car. It's just not economically efficient to try to use it as you would have to add a lot of complexity to control the charge level.

3. Keep repeating "The Prius is NOT an electric car, the Prius is NOT an electric car....." because IT ISN'T!!! Yup, it's electronic, but it runs on gasoline!

Now, you -could- make a circuit that keeps the 12V battery fully charged from the solar panel. No harm there. But again, is it worth the cost to -every- person or even the majority of people who buy a Prius?

 

I always wondered about the Solar Electric Vehicle guy out of California. He has developed a solar panel for the roof of a Prius which he couples with a series of lead acid batteries (I know, time to upgrade that system to Lithium!) for a plug-in hybrid conversion. What do you think of his approach?

Here's the linkie: Solar Electrical Vehicles