RC India

I planned on making a solar powered rc plane the problem now I am facing is how I am going to integrate the panels in such a way it charges the battery also allowing simultaneous discharge of the battery

The problem with this setups is that the RC motors need a high amount of current while keeping the plane in the air.
To get such current, you would need large Solar panels, which in turn will make the plane unflyable.

You would need a constant and reliable supply of atleast 10 Amps just to make the plane fly. To charge the battery at the same time, you would need even more.

Unless and until we do get the technology of ultra efficient solar panels it's best to stick with LiPo's.

Sir, what is the size and weight of each solar cell/ panel, and voltage / amps output?

I second Bhavesh's observation...One would need realllllly large solar panels, till technology gets better, maybe

Not so easy bro. The one solar Panel which U can mount over the plane ll be very small, n it can produce currents in the range of 10 to 20 Watts, and even that current is not constant. you can build a bigger plane infact of Gigantic size to mount panels which can produce enough power to recharge a lipo battery. If ur using a 2200mA battery then it ll require a current of around 2A to charge the battery, even in this case the battery will consume more than one hour to get fully recharge, dont forget the current I am talking about is continuous supply not a panel. PS: Free Energy is not so easy to Harvest and Utilize.

@siva_uchiha
@miginstruments

Instead of general phattas, can we have specifics please?

Solar panel size, weight, voltage, amps please.

(BTW, I built my first solar cells way back in 1972. Thay were very bad. Due to multiple layering, they produced high voltage but only few microamps current)

(Also BTW, 10amps not really required to fly. You guys must have seen my flying videos at  3amps on 2s, ie, under 25 watts, on this forum!)

If you look around the web a few Prototype real life gluders were made for this very application , the problem is they have huge huge wingspan and large amount of solar pannels to support its flying . I doubt any of that can be achieved in a model plane

OK guys ?! I get it but I just need a circuit where I can recharge the battery simultaneously as it discharges the rest I can't say for sure until I start doing it so please ?!

Use a basic charger which operates on a DC source.
Like this one:
http://www.rcbazaar.com/products/1096-2-3-cell-lipo-simple-charger.aspx (http://www.rcbazaar.com/products/1096-2-3-cell-lipo-simple-charger.aspx)

About discharging, LiPos comes with 2 cables.
One for charging while the other for discharging.

So the motor will run through the the thicker discharging cable of the LiPo. While the lipo will be getting charged through the thinner (Balance) charging cable.

You can use any small balance charger to charge your batteries which works on 12v DC. Thats what guys did HERE (http://flitetest.com/articles/our-solarplane-dreamship-surprise/)

If you feel you wanna go the DIY way then check HERE (http://www.zajic.cz/omezovac/omezovac.htm) (use chrome browser for translating the page)


 

Sorry posted in the wrong place.

can any one tell wheather a lipo battery can charged  and discharged simultaneously.will it burn the battery? :headscratch:

btw you can search on ebay.18volt monocrystaline panel,flexible.0.55amp peak current ,180gram and costs 5670

It won't create any issues for the battery.
But it might create glitches in charger and/or ESC and they might start behaving abnormally.

Guys the basic thing is Charging requires more time than discharging. A 2200mA takes more than one hour to get charge completely when charged with a basic charger. But if one uses the same battery for a 1000kV motor, then it will get discharged in around 25-30 mins.
@Siva_uchiha  What are trying to do with this circuit by the way.

The fundamental issue remains power/weight.

Currently commercial Solar P-V Cells are 180 micron thick.

This article from Forbes might trigger something:

Designing a solar-powered drone isn’t just about slapping on as many solar cells as possible, though maximizing the use of the available space is certainly a key consideration. One factor to consider is the weight and efficiency of solar cells. The vast majority of the solar cells produced today are too thick and heavy or not terribly efficient for use by a drone, which needs to stay lightweight and nimble while carrying a camera or other equipment. Adding weight will require more battery power to operate. Alta’s cells, made with gallium-arsenide, are 1 micron thick, compared with the common 180-micron silicon cells that you find in most of the solar panels on the rooftop today. Alta’s cells also are more efficient at converting sunlight into electricity than thinner solar cells made with compounds such as copper-indium-gallium-selenide or cadmium-telluride.

Finding suitable surface areas to plant the solar cells is another design goal. The wings and tail are typically where the solar cells go. But cells can stick to the underside of the aircraft, too, in order to capture reflected light that is often available when the drone flies over a desert or snow, Norris said. He declined to disclose where Alta’s cells are on the prototype Puma or how much electricity they could produce, citing the secretive nature of engineering drones with military use in mind.

Except for the above, no one has yet shared data (from personal experience, preferably) on size, weight, and volts/amps output. Without this it's all hearsay.

Can we get say 12v, 2-3amps from a panel under 2sqft area, weighing less than 200gms. (Cost considerations apart)

If yes, easy to build a viable solar powered model.

Got to get back to Wiki or HK i guess...

I think the original poster wanted to charge the battery from solar cells while using the battery to fly.
Then why use a battery at all? Why not direct solar power?
After all it's not hard to charge the battery on the field using the cig lighter in your car  ;D

Unless of course the idea was to leave the model in the sun for 2 hours between each 2 minute flight.

tats what am trying to say. KK sir with all due respect this cannot be possible even with a handful budget. all I know is the power produced by the panel is not constant, besides voltage here is not the issue, its the current that is going to play the major role.. I won't think a simple panel will produce enough amount of current. plus after the conversion of light energy into electric there are losses which will again reduce the current.