adding a small solar panel?

Discussion in 'Prius c Accessories and Modifications' started by mulu, Aug 29, 2015.

  1. mulu

    mulu New Member

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    hello, is it possible to add a trickle charge photovoltaic panel to the prius c, that would sit on the dashboard and plug into the outlet?
    I am not looking to add a large solar panel to the roof... I just want to add a small one.
    I guess I'm just not satisfied with getting 65mpg every day.
    okay truth be told I got 70 today.
    see B00EB3OC9W on amazon
     
    #1 mulu, Aug 29, 2015
    Last edited: Aug 29, 2015
  2. djdawn

    djdawn Active Member

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    I don't believe the EV battery and the 12v line have much to do with each other. Additionally, my 12v accessory socket turns off with the car, making me think it's relay controlled, disconnecting the 12v battery from the socket.
    However, I'd like to be wrong in this as it would open up additional electrical mods. I have a solar array on the "trunk lid" thing in my 2014 C2, but it powers a 5v battery for internal accessory use. tbh, I have a hard time believing even a large solar array could charge the EV battery to a noticeable level in a reasonable amount of time.

    [​IMG]One of the five panels showing in this pic, covering most of the trunk lid. 5V @600mA in parallel in theory makes 3A @ 5V, but realistically because it's inside the car it makes about 1.8A @ 5V. That's 9W of power, I doubt that would make much of a dent to the EV battery if setup to do so.
     
    #2 djdawn, Aug 29, 2015
    Last edited: Aug 29, 2015
  3. TheTimob

    TheTimob Member

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    I have a large solar panel - 36 inches by 12 inches. It puts out 15 watts at 12 volts. I use it as a trickle charger on the 12v battery for when the car is parked for extended periods of time. In the winter - it's on the trunk shelf of my Scirocco - to keep the battery okay.

    In the summer it goes onto the Prius's dashboard because I drive the Scirocco more often - the rear window is too vertical on the Prius C. Its charge controller is wired directly to the 12v battery under the rear seat via a fuse and cigarette-lighter type outlet.
     
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  4. bisco

    bisco cookie crumbler

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    just wire it right into the hybrid battery, that should keep it topped up when you're in the sun.
     
  5. djdawn

    djdawn Active Member

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    Oh no.. :eek:!
     
  6. bisco

    bisco cookie crumbler

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  7. djdawn

    djdawn Active Member

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    Again I'd like to be wrong because it would open up an obscene amount of electrical mods, but I believe the EV battery is a ~200V of iono mA. Hooking up a 12V trickle charger wouldn't do anything because it's the wrong voltage.
     
  8. bisco

    bisco cookie crumbler

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    ah, i didn't realize that, thank you! so, it's impossible to charge the battery with solar?
     
  9. fuzzy1

    fuzzy1 Senior Member

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    Won't do anything? Well, it won't do anything good, that's for sure.

    I'd be extremely concerned that the 12V-rated device won't withstand the far higher traction battery voltage, and will complain with sparks and smoke and fire.

    Any solar charger will also violate the traction battery's internal shutdown isolation, creating a safety risk to emergency responders and mechanics.
     
    #9 fuzzy1, Sep 2, 2015
    Last edited: Sep 2, 2015
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  10. djdawn

    djdawn Active Member

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    It's definitely possible, but making something that would put out ~200V that would be capable of making a dent in the EV battery (with the specs I think it has) would be huge. #'s out of my backside, about 20 square ft large. Assuming I use parts I can obtain as a normal person to make something that's capable, that would produce ~200W. That would be ~200V @ ~1A.
    But again, 20 square ft is a lot of space.
    In terms of ability, that's what I meant by saying the 12V solar charger wouldn't do anything. Please don't attach a solar charger to the EV battery.. that would be bad.

    Fuzzy1 was more straight to the point, but I agree with what he says as well. Put bluntly, I don't feel I know enough about the EV battery and working in the 200V range (and associated circuitry) to feel safe doing it. I'd worry if I'm breaking some weird DOT laws by playing with the EV battery as well. I'd recommend being an EE with experience with this, and even then there's bound to be some wierd DOT thing wrong with it.
     
    #10 djdawn, Sep 2, 2015
    Last edited: Sep 2, 2015
  11. wjtracy

    wjtracy Senior Member

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    I've been thinking about having the small panel at the house charging some 12v batts and then using the power to run a engine block heater of some kind (say a 40w infrared light bulb under the car) to generate some heat. Or in winter locations maybe heat the car interior with a light bulb. Anyways have not implemented yet. I wanted to set up a monitoring temperature readout to see if these things made a difference.

    What I really like is I wonder if new PiP2 has induction charging, run that off solar and 12v batts/w inverter of course if possible.
     
    #11 wjtracy, Sep 2, 2015
    Last edited: Sep 3, 2015
  12. SwhitePC

    SwhitePC Active Member

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    you should think about adding like a wind turbine on top of your car...it'd probably get better charge for your hv battery...and not to mention the faster you go the more energy you get!!! =P

    anyways, just be happy with your 65mpg...my lead footed butt is pretty happy with 45-50mpg
     
  13. djdawn

    djdawn Active Member

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    I mentioned it in an earlier post, so posting another pic of the solar panel over the rear trunk. The panels are wired in parallel feeding a 5v usb charger in the armrest. That later feeds my wife's phone and bt headsets as needed, and into a usb hub that feeds whatever is plugged into it in the rear seats.
    [​IMG]

    Not as cool as charging up the EV battery, but it saves on whatever load charging the misc devices would have caused if it sat on the regular 12V line with a 5V adapter. This way it's collecting passive power from the solar panels.
     
  14. Gerry miles

    Gerry miles New Member

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    I have one of those folding out solar charger panels, I plugged it to my cigarette lighter on my Prius c2, and when I got out of the car and hit the lock on the key fob,nothing happened, the car doors would not lock, until I disconnected the CIG lighter charger,then the doors would lock up from the key remote fob.
    My question is now that everyone knows you can't effectively charge the ev batteries, but can't you charge the 12 volt battery that is used for starting your engine,thru the CIG lighter route to trickle charge the battery during the winter months ? And why did that connection interrupt my remote keys from locking my doors. ?
     
  15. fuzzy1

    fuzzy1 Senior Member

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    That power outlet is shut down when the car is turned off, so there is no electrical charging path back to the 12V battery. This is necessary on modern cars to prevent people's plug-in devices from draining the battery when parked.

    Your solar panel was built for older style cars where the outlet remained live. To charge a modern car, you will need to wire it in through another path.

    I suspect the car would not lock because your solar panel tricked some essential circuit into believing the car was still on when it detected power still present downstream of the ignition switch.
     
  16. Ceethree

    Ceethree Junior Member

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    What if I just wanted to assist with some of the accessory load while the car was running? Would a small solar array (perhaps like some shown here by others) help with this? For example, driving in town in heavy traffic isn't so bad unless it's a hot day and you're running the air conditioner (or heater on a cold day). I doubt you could manage an effective enough solar array to manage the entire load of the HVAC, but could it be possible to assist with some of the load? The shorter the time the engine has to run, the better the mileage! The next question with this is regarding the most effective means of connection.
     
  17. fuzzy1

    fuzzy1 Senior Member

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    Will it assist? Yes.
    Will it assist enough to more than offset the extra fuel needed to haul the extra weight of the device? I don't know.
    When running, the solar boost is small enough to be pointless. If done right, the 12V charging assist while parked will be much more meaningful.
     
  18. ftl

    ftl Explicator

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    In his post above, TheTimob said: "I have a large solar panel - 36 inches by 12 inches. It puts out 15 watts at 12 volts."

    Meanwhile, after making measurements on a Gen 3 a few years ago, BrettS reported:
    "I was a bit surprised to see that the AC was drawing 1750 watts when I first started the car... but in its defense, it was nearly 90 degrees out and the car had been in the sun, so the interior was probably much warmer than that. After the car had been running for a while and the interior had cooled down it dropped to only 650 watts."
    How many volts does the GEN III AC Compressor run at? | PriusChat

    Comparing the numbers, you'd need an *awfully* big solar panel to make any difference at all with the air conditioning load of a Prius.
     
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  19. TheTimob

    TheTimob Member

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    with only 15 watts out of a panel this big - it's not even worth it's weight to drive around with it in the car.
     
  20. Sean Nelson

    Sean Nelson Active Member

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    It's worth remembering that even the full-sized, fully optioned Prius with its built-in solar panel roof doesn't attempt to run the air conditioner. The solar panel is just used to power the climate control fan when the car is turned off so that the interior air is regularly exchanged and heat doesn't build up inside the vehicle. A fan doesn't require very much power to run but it can make a huge difference in the interior heat level of a parked car.

    I think it's a brilliant idea and I wish that option were available on more cars.
     
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