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  • #16
    Originally posted by Sunking View Post

    Good ole Youtube, the Idiots Bible.


    I fly 3D RC Planes and the last thing you want to do is use solar to charge your Rc LiPo batteries. Why would you want to wait all day to charge a battery? Even after a day may not be fully charged.

    Our club does have a Solar Rig to charge LiPo batteries. I built and designed it. It is a 500 watt panel with a 24 volt 100 AH lead acid battery and uses PL8 Hobby Charger. The secret to it is the Lead Acid Battery, the panel cannot supply the 1300 watts the charger can demand. Trust me all us club members would throw that solar system away in a heartbeat for good ole AC power. With the solar system only one lousy battery can be charged up at a time. Does not work so good with more than one pilot trying to fly and charge batteries. The lead acid battery does the real work and charging.

    The real solution to flying electric planes is to have 5 to 10 batteries and take them with you fully charged.
    I'm glad you are in the same hobby, i was asking about the solar battery on the plane to operate, its a glider so i have surface area to work with for panels, now for the topic of a charger station, is there a way to build a solar/battery set up that charges batteries, i don't mind if it takes double the time, i charge 8 batteries at a time with my HiTec charger:

    http://hitecrcd.com/products/charger...harger/product

    I see people bringing lead acid batteries to the field and charging, so i believe we cant be that far off when charging via solar.

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    • #17
      Originally posted by J.P.M. View Post

      U-tube: The new Idiot's' bible.
      haha i like your quote....well at least THIS idiot spelled YouTube correctly.

      And i look at all sources before committing to a project.

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      • #18
        Originally posted by Tesla View Post
        And i look at all sources before committing to a project.
        Me too. I always check the National Enquirer along with other sources for reliable information. I, like you it seems, practice real and critical discernment of sources.

        I'd also respectfully suggest you check you first post for caps, syntax and sentence before throwing too many stones. Just sayin'.
        Last edited by J.P.M.; 12-17-2017, 01:51 PM.

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        • #19
          Originally posted by Tesla View Post
          I see people bringing lead acid batteries to the field and charging, so i believe we cant be that far off when charging via solar.
          No where close or practical. Your Hitech charger, and such chargers are made to operate from a stiff source of power. Stiff source means it can provide any amount of power required indefinitely. Solar is not a stiff source. At any point in time the amount of power is unknown other than it WILL NOT BE say 100 watts on a 100 watt panel ever. Only at noon will a panel produce its maximum power and that is only for a few precious minutes. Your charger would not work period. That is why the Lead Acid battery or some kind of buffer battery is required.

          With 8 charging ports, you just made it 8 times more impossible. That is why you see people bring large lead acid batteries to charge their LiPo batteries. Exact same reason our flying club uses one. It is the only way to make it work economically.

          Now it is possible to do with solar if you have design experience, money is no object, and throw practicality out the window. Give you an example. Say you have a small charger like a iCharger 1010B+ a 300 watt charger. Solar panels output power varies with the intensity of the sun. A 100 watt panel in the morning starts out with a few watts in the morning and builds gradually until noon when it peaks at 80 to 85 watts assuming crystal clear blue skies. After noon power fades to 0 watts by sunset. The iCharger needs 300 watts available anytime while in use. The only way to do that is if you used a grossly over sized panel of say 1000 to 1500 watts.

          Next challenge is you would need to design and build a custom regulator to interface the panel to the charger.

          As you can see that is just not realistic. The best way is to do what I did. Use a moderate sized panel of say 500 watts with a conventional solar charge controller and a 24 volt lead acid battery. A 24 volt 100 AH Pb battery on a full charge can handle as many 3S to 6S batteries you can throw at it in a busy weekend. At the end of the Sunday would be fairly deeply discharged around 50% discharged. But like any club is only busy on weekends. The panel has all week long to recover for the next weekend. That system cost me $1000 to construct. The bad news about the system is it can only handle one charger at a time. I don't use it. I charge at home, I have over a hundred LiPo batteries. I can fly all day long with only a few minutes between flights. Just enough time to cool the motors and change out batteries.

          There is one other way, but requires a solid design experience. Still have to use an grossly over sized panel. The trick is to design a charge controller to charge the LiPo's directly. That is no easy project and requires a lot of DC to DC Power Converter design experience and a means to fabricate the circuit board. I am a professional electrical engineer of 40 years and would not take it on unless it is for a production model. It would hundreds of hours of my time. My time is worth $100/hour or more.

          So what you are seeing is smart money. Guys buy a pair of 6-volt golf cart batteries or a smaller 12 volt deep cycle battery, an inexpensive AC charger to charge the battery at home, and take to the field. If you went solar requiires the same battery plus a whole lot more money for the solar that does not work out like you think.
          MSEE, PE

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          • #20
            Originally posted by Tesla View Post

            I'm glad you are in the same hobby, i was asking about the solar battery on the plane to operate, its a glider so i have surface area to work with for panels, now for the topic of a charger station, is there a way to build a solar/battery set up that charges batteries, i don't mind if it takes double the time, i charge 8 batteries at a time with my HiTec charger:

            http://hitecrcd.com/products/charger...harger/product

            I see people bringing lead acid batteries to the field and charging, so i believe we cant be that far off when charging via solar.
            There have been a number of RC pilots that have built solar gliders. The biggest problem is to get any good charging you need to cover the entire upper surface with cells, but the extra weight makes the plane heavier thus needing more boost or much better thermals.

            Where I have seen solar work is on a large "powered" glider. That allows the flyer to only use the electric motor to run the prop a short time to gain lift and the cells can put back some of what is used.

            No one has built a solar plane that can charge the batteries faster then they are discharged so unless the wind is in your favor and you find them thermals your plane will eventually land.

            So like Sunking said the best way to fly RC is to have a lot of extra LiPo's in your bag.

            Although I did build a small solar / battery system to charge my LiPo's at fields that don't have power. It was fun to build but kind of expensive at around $500.

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