Hacking the solar?

It looks his circuit has no shut-off capability when the SOC is high, but the charge ampere is very little.
Anyway, I'll ask him about that.

Ken@Japan

 

i got a panel half the zise he got and its only 10watt..
can you ask what type panels he is using.

i am thinking about ( not sure what the price is for those panels and also it can be stolen so have to find a good way to lock them on the roof rack.) placing 100-200 watt panels on my roof..

but then i need a cheap Dc-Dc converter
i maybe can use the chematic that you have posted from the dc-dc converter used by him.

 

It's just a generic solar panel, but he measured the capability by himself.

He has enough knowledge to design his own charging system to meet the solar panel specification.

Ken@Japan

 

That's an interesting thought. I'm sure anything is possible with enough time, money, and smarts. Come on, PriusChat, you can do it!

 

Could pick up some of these flexible panels and then you could get them to sit flat on the roof:

Uni-Solar PVL-136-136 Watt Laminate

At 5 meters long, though, it might be tough to find a surface big enough to fit them on the car!

 

The space available on my Gen2 roof is about 41" wide by 52" long, plus an extra 9" length if we ignore the antenna. The Uni-Solar laminate is 15.5" wide by 216" long.

The Uni-Solar PVL-68T 68 Watt Laminate ($316) is 15.5" wide by 112" long. It would probably do the trick if you can cut it to half length. Use two 56" by 15.5" strips, leaving at least 11 inches of open space for the antenna.

 

I just wanted to comment regarding the naysayers who think the panel is an expensive marketing gimmic...

While I will concede that the marketers are throwing the word solar around, I will point out that it is in no way a $3,600 dollar option. Subtracting out the NAV package, and it is an $1,800 option. Subtract out the sun roof, and it is a $700 dollar option.

Now, is it worth it for 700 bucks? Considering that a generic similar panel that is not designed to fit the roof of the car costs about 400 dollars, you have a $300 markup. Consider the extra circuitry, and extra computer, that is thrown in the car, and I think you have a fair deal price wise.

But does it work? In Florida it does. My car sits in the sun all day everyday. As a test, My wife's Altima was parked in our driveway, next to the Prius. Neither of the cars currently have tinting, and they were both there for the same time and faced the same way. The cars have a similar amount of glass. The interiors are similarly colored. At noon, we placed a thermometer inside her car. 125 degrees. My glasses fogged up when I opened the door to read it. The steering wheel was too hot to touch. The metal parts burned.

The Prius was 92. The instant the car was running, cool enough air was comming out of the vent, that when directed on me, made me feel pretty comfotable. In the altima, I couldn't press my back against the seat for about 10 minutes. It took nearly 10 minutes just to get what i would consider cool air - before that, it was blowing very hot uncomfortable air out like a hair dryer. After 15 minutes of AC running, the air was comfortable enough, but the surfaces in the car were still putting off so much heat, that the AC was still struggling.

Compare those experiences and consider that temps cause that 6 to 8 months out of the year. I'll take that feature anyday over LED headlights (Not that I'm bashing them, I think they are great and would want them, I'm just talking added utility here.)

 

I wanted to follow up under a different message to stay true to the intent of this thread. Mods.

In looking over the wiring diagram, I think a trickle charger for the accessory battery could be doable.

My idea would be to ignore the panel itself, and let the Prius manage the power rectification. I woudl say that a switch could be installed at the point where the voltage is supplied to the blower itself. At that point, the Prius electronics would not know or care that the proper voltage is powering something else other than the blower.

The convienant thing about that is it is near the dash. Now. If you can tap into that rectified power, and connect it to one of those 12V plugs (assuming you mod the outlet to be wired directly to the battery, or always on) then couldn't you just plug it into the socket for some trickle charging? I would expect some basic circuitry may be requried. But isn't that the gist of it?

 

you need a solar charger
this got a variable input and 13,5 or so output with a charge system to stop when the 12 volt battery is full

 

Good point. The real message in my post was to consider tapping the power output of the panel at the blower feed, rather than directly from the panel itself. It just seemed a bit more predictable.

 

ha ha hawwwh, ! !
Caveat, the above statement from the guy who lives to take stuff apart. Behold . . . darell's step by step dash disassembly:






.

 

That's pretty much the same conclusion I came to about the SR at all. And I live in Miami, I bet they were really convinced I'd buy the SR!

Still directing the power from an aftermarket (in my case) PV array could power a 12volt plug for say, a seat cover type cooler, GPS, Cell phone, top up a spare booster charger so you don't use jumper cables, trickle charge the 12v, the possibilities are almost endless.

 

Okay - I subscribed to TIS for the weekend and downloaded the electrical schematics on the solar venting (but left the PDFs on my work computer!) and these will take some review to figure out which end is up. The diagram is a lesson in how to create a hopeless schematic, with convoluted connections flowing between acronym laden blocks. I'll keep at it after I remember to bring them home.

In principle, the solar panel is always producing electricity as long as there is light. The temperature sensitive controls simply gates that voltage based on interior temperature and probably monitors the output voltage of the panel. So I expect to find panel connected to controller with not much in between.

We want panel connected to solar controller, like the Sunforce in the link below, which is connected to a small 12V sealed lead-acid cell battery installed in the trunk. I like the Panasonic also linked below. We then wire an accessory plug off the Panasonic battery. Panel keeps the battery charged and we charge electronic goodies from it.

If we parallel connect our solar controller with the Toyota vent controller, then we may have interactions (we load the panel at the point that the vent controller wants to run the fan). Especially if we're loading down the panel voltage and the vent controller is monitoring panel voltage as one of it's inputs to make the decision to kick on the blower.

If we disconnect the panel, even temporarily, the Toyota vent controller may get upset (might be looking for residue voltage or panel impedance to know that it's connected).

My plan:
1) Study the schematic and try to figure out as much as possible. I only bought the 2-day TIS subscription so I'm SOL if it references information elsewhere on the site.
2) Concentrate on understanding the solar vent off switch function - it may be possible to use it as input to a double pole relay that throws the panel leads to our controller when in the off position.

Just a starting point - feel free to jump in anywhere!http://www.amazon.com/dp/product/B0006JO0XI?tag=priuschatcom-20

 

I've downloaded a ton of info on the solar panel system and here are some interesting tidbits:
1) The panel is capable of 22V and 3.6A, making it an 80W panel
2) The Solar Ventilation system Electronic Control Unit (ECU) is looking for 10V from the panel as minimum input voltage (along with other inputs like the temp sensor and ignition switch).
3) The panel is negative chassis grounded and only the positive green wire runs to the ECU and goes into the SB1 input.
4) The positive output from the panel goes through connector block LR1, which is a major connector available on the lower left hand (drivers) side.

I haven't traced out the SB1 wire yet, but my belief is that we could tap into this wire and route the solar panel output voltage to a solar controller. I need to do more research on the input voltage range of some solar controllers to make sure that they can handle the 22V that the panel will generate, but a quick read seems to indicate that this is standard for panels intended to charge 12V batteries. Most 12V lead acid batteries will charge to 14-15V so the panel would need to provide margin above this. One controller manual's troubleshooting guide indicated that the open circuit voltage on a standard "12V" solar panel would read 22 to 24V with no load.

So - baby steps forward but it seems likely that we can lightly tap the panel output (100-200mA) without impact to the solar ventilation circuit. That would be well within the trickle charge level for a modest sized gel cell battery.

More to come as I trace out the wiring and get some measurements. Stay tuned...

 

Nice work neutronned. Seems like you'd want to put the solar controller directly on the positive lead of the panel (in between the panel and the ECU), no?

That way, the controller will maintain 12v so the ECU will still turn on even if the voltage of the panel drops below 10v.

(Apologies if that's what you meant and I misunderstood!)

 

this even want me to get a solar roof gen 3 prius
and make it recharge the 12 volt battery and maybe even a small secondary battery or direct dc-dc converter to charge a little back into the prius HV battery

just like the friend of ken@japan with the 45watt solar panel on the roof of a gen 2 prius.

this will double that output and be more aerodynamic.

 

Your source for that info would be? Everything so far has shown it to be 60 watts.

Wayne

 

He mentioned that he downloaded the data from Toyota's Tech Info web site: techinfo.toyota.com

 

FireEngineer is correct.
We can't get 22V(max volt) and 3.6A(max amps) at the same time.
Following is a sample graph posted #63 of this thread.
It produces 22V max voltage and 2.8A max amperes, then it's max is 40W.

Ken@Japan