So I really want to build a solar powered glider for fpv or just flying around for a really long time. I'm thinking of buying solar cells from eBay or amazon. So my question is should I use the solar cells to power the motor directly or use the cells to charge the battery in mid flight? I'm not shore how to use a lipo battery as it's charging if you can but I don't want my plane to drop out of the air when a cloud comes over. I think I can get the cells to a voltage the same of a 3 cell lipo. I just want to power a blue wonder but I have no experience with solar panels so any help will be great. Thanks
rcspaceflight
creator of virtual planes
I'd think that the easiest way would be to get a brushed motor and power it directly off of the solar panels. Then use a LiPo to power the Rx and servos. You would be limited by the LiPo because even though servos and an Rx don't require a lot of power, they will still eventually drain the LiPo completely.
You may not even need any sort of throttle, but at least an on and off switch for the motor.
You may not even need any sort of throttle, but at least an on and off switch for the motor.
The bigger the glider, the easier it'll bear the added weight of the panels. You may have a hard time getting thrust necessary to get the glider to altitude early on, so perhaps a high-start motor-glider?
Might be worthwhile looking at output wattage of the panels under normal circumstances and figuring out what motor to mount given that information. I'd agree that in-flight charging is problematic. For one thing, how will you safely charge the lipo batts without balancing?
I suggest using an online calculator to determine what wattage you can run.
Might be worthwhile looking at output wattage of the panels under normal circumstances and figuring out what motor to mount given that information. I'd agree that in-flight charging is problematic. For one thing, how will you safely charge the lipo batts without balancing?
I suggest using an online calculator to determine what wattage you can run.
rcspaceflight
creator of virtual planes
To add to what I already said, I thought about doing this too and I was going to make a physical switch powered by a servo to turn the motor on and off. My concern was landing. You'd want the motor at least off for landings.
To add to what Jtnb said, a larger glider is the way to go. You may want a 2200mah 3S (or 2S) battery in it so you can get a really long flight time. Servos eat power, not just the motor. Plus if you do put FPV equip on it, that'll eat the battery quicker. You may not have to go ridiculous, probably at least a 60" wingspan.
http://www.flyrc.com/wing-load-calculator/ Use this calculator to figure out the wing cube loading. 3 to 4 is what you'll want.
I'm not sure you'd be able to use your blue wonder or not. If you do, do NOT use that ESC to power the Rx. You'll likely to get power drops, brown outs, and black outs when powering it with solar panels. Get a 12v solar panel, do not plug the red wire of the ESC into the Rx, use a different ESC or BEC to power the Rx, hook it all up and see what happens. But I'd think that cloud cover may drop the volts and amps to the point that you burn out the ESC or motor. A brushed motor may be the way to go just for the simplicity of it. Hook the motor directly to the solar panels with either a relay or a physical switch powered by a servo to turn the motor on and off.
To add to what Jtnb said, a larger glider is the way to go. You may want a 2200mah 3S (or 2S) battery in it so you can get a really long flight time. Servos eat power, not just the motor. Plus if you do put FPV equip on it, that'll eat the battery quicker. You may not have to go ridiculous, probably at least a 60" wingspan.
http://www.flyrc.com/wing-load-calculator/ Use this calculator to figure out the wing cube loading. 3 to 4 is what you'll want.
I'm not sure you'd be able to use your blue wonder or not. If you do, do NOT use that ESC to power the Rx. You'll likely to get power drops, brown outs, and black outs when powering it with solar panels. Get a 12v solar panel, do not plug the red wire of the ESC into the Rx, use a different ESC or BEC to power the Rx, hook it all up and see what happens. But I'd think that cloud cover may drop the volts and amps to the point that you burn out the ESC or motor. A brushed motor may be the way to go just for the simplicity of it. Hook the motor directly to the solar panels with either a relay or a physical switch powered by a servo to turn the motor on and off.
This Instructable just came up on my G+ feed and I thought it might be of interest here:
http://www.instructables.com/id/Introduction-47/?ALLSTEPS
http://www.instructables.com/id/Introduction-47/?ALLSTEPS
stay-fun
Helicopter addict
Interesting! I have a different opinion than the others here 
. I think what I would do is have some simple circuit to charge the battery in flight, so you don't need to deal with brushed motors, servo-controlled switches and such (apart from the fact that brushed motors are less efficient... and efficiency is something you need here!).
There are these very cheap lipo battery chargers that charge exclusively using the balance port of a 3s lipo. Maybe that could work? I only hope it will still charge (at a slower rate) when the input current is lower.
There are solar chargers for single lithium batteries around, maybe you can look into those? And then using a BEC to up the voltage to something useful (make sure the BEC can do that - most BECs can only lower the voltage).
Anyhow, if you really just want a long flight time, use a big battery! If you're doing this as a fun, technical challenge: good luck!
. I think what I would do is have some simple circuit to charge the battery in flight, so you don't need to deal with brushed motors, servo-controlled switches and such (apart from the fact that brushed motors are less efficient... and efficiency is something you need here!).There are these very cheap lipo battery chargers that charge exclusively using the balance port of a 3s lipo. Maybe that could work? I only hope it will still charge (at a slower rate) when the input current is lower.
There are solar chargers for single lithium batteries around, maybe you can look into those? And then using a BEC to up the voltage to something useful (make sure the BEC can do that - most BECs can only lower the voltage).
Anyhow, if you really just want a long flight time, use a big battery! If you're doing this as a fun, technical challenge: good luck!
stay-fun
Helicopter addict
Oh! What you could also do is a separate motor power system, and servo/RX power system. Maybe you can use a very small 4s 200 mAh NiMH pack as receiver pack, and solar charge that! Those batteries are less sensitive to over-charging. Then use a small separate LiPo for your motor, which at some point will run out...
Just throwing out options here
Just throwing out options here
stay-fun
Helicopter addict
ALL my flying, computer usage and Ham Radio activities are solar powered!
Thurmond
Nice! So you're not using the nuclear ITER reactors (those use Tritium as fuel
)? Nice! So you're not using the nuclear ITER reactors (those use Tritium as fuel
Fusion......er, yes, Sorry can't really say anything more about that! FAA gets really testy if they suspect nuclear powered aircraft. Not to mention MANY other 3 letter Government entities.
Thurmond
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