Hacking the solar?

[HTMLSpinnr]

So one of the first things that has come to my mind - AZ has over 300 "sunny" days per year. If that solar panel is ONLY going to run vent fans, there's times of the year when it could be doing other things. Once we're able to download electrical diagrams, how many would be interested in looking into wiring up a float charger for the 12V battery, or directing that power elsewhere when the vent is "disabled"?

This, of course, assumes Toyota didn't design this feature already.

[neutronned]

Call me gutless, but this sounds like a warranty breaker to me. I'll be disappointed if they don't already use the solar cells to top off both batteries. Seems like a natural to me to trickle charge the 12V battery and not much extra work to charge the motive battery.

Anyway, I'll help read schematics and make suggestions but I'll have to stop there. Even if I wasn't worried about voiding the warranty, my wife would kill me if she saw me cutting into and soldering up our new Prius.

[qbee42]

Originally Posted by neutronned

Call me gutless, but this sounds like a warranty breaker to me. I'll be disappointed if they don't already use the solar cells to top off both batteries. Seems like a natural to me to trickle charge the 12V battery and not much extra work to charge the motive battery.

Anyway, I'll help read schematics and make suggestions but I'll have to stop there. Even if I wasn't worried about voiding the warranty, my wife would kill me if she saw me cutting into and soldering up our new Prius.

It only runs the fan. Toyota was very clear on this issue.

Tom

[HTMLSpinnr]

Nobody claimed it warranty safe. However, the "right" way to go about it would be to locate a harness and build in a Y adapter, or some sort of "board" to fit between. No wires broken, and worst case, you remove the unit should it become a problem.

I took the same approach w/ the EV button on the '04 when determining how to integrate w/o the existing hardness. I did "tap" some wiring, but not in a manner that was destructive or irreparable. I knew it was a possible warranty voider, however made it easy enough to remove should it be required.

Given our trend of the EV button hacking, and it now showing up in the 2010 (Thanks Toyota), the efforts for solar to do other functions could easily be OEM integrated in the future should they prove viable.

Some of the solar challenges to "overcome" would be voltage regulation and current backflow (nothing like discharging a battery back through the panel overnight or on a cloudy day). The more challenging feat would be integrating w/ the override switch.

I'm not an EE, just a guy w/ ambition and ideas, but not w/o some common sense ;-)

[darelldd]

Yeah, you've got to pay to play. As long as you don't break anything, then no warranty can ever be voided.

Rick - it is easy to prevent backflow with a diode. Charging the 12V would likely be quite simple. Charging the HV battery would be too complex (expensive and ineffective) to make any attempt worthwile. I think it should just power a propeller on the top of the car when it is doing nothing else. You know -like a propeller beanie. It does drive me nuts that around here that PV panel would only be put to use about five months out of the year - the rest of the time I WANT whatever heat is collected in the car to stay there! What a waste of product!

[HTMLSpinnr]

Right sizing the diode, if not already present, would be the only simple challenge.

I had no illusions of doing the HV battery, by the time you run through a step-up transformer (and it's losses), there's probably not much current left to be effective.

[qbee42]

Originally Posted by darelldd

Yeah, you've got to pay to play. As long as you don't break anything, then no warranty can ever be voided.

Rick - it is easy to prevent backflow with a diode. Charging the 12V would likely be quite simple. Charging the HV battery would be too complex (expensive and ineffective) to make any attempt worthwile. I think it should just power a propeller on the top of the car when it is doing nothing else. You know -like a propeller beanie. It does drive me nuts that around here that PV panel would only be put to use about five months out of the year - the rest of the time I WANT whatever heat is collected in the car to stay there! What a waste of product!

I could use it for a couple of days in August. The rest of the time snow would block the PV panel.

Tom

[spwolf]

there is probably good reason on why it runs only the fan too :-).

[qbee42]

Originally Posted by spwolf

there is probably good reason on why it runs only the fan too :-).

Probably the main reason is that the PV array doesn't generate much power. Toyota probably figures that the cost and complexity of routing that power to the 12V battery is not justified. Routing it to the HV battery is silly.

Tom

[efusco]

Originally Posted by spwolf

there is probably good reason on why it runs only the fan too :-).

Such as?
Other than cost and additional circuitry I can't think of any. Why not use it to power the 12v accessories and computers while you're driving? A tiny benefit I grant you, but it's something and it's better than letting the expensive solar array sit up there on the roof unused.

Why not allow it to float charge the 12v...particularly when it's sitting unused for a week or more in an airport parking lot?

It adds complexity to the system, indeed, but it also makes the cost of a PV panel like that a bit easier to swallow knowing it's doing something any time there's sunlight for it to gather.