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Ordinary solar panels for home made CubeSat picosatellites

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narder

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About a battery charger with solar panels and its use for CubeSats

I have a battery charger (Model Number CH-4632-ECO) which I bought together with four rechargeable batteries, for less than 25 dollars. I have always charged the batteries by plugging this device in the outlet and I have never been able to charge them using its two small solar panels (3 1/2 X 1 1/2 inch each). I put the charger, repeatedly, for a few days outdoors, with its solar cells oriented in the same direction as the panels of some autonomous electronic devices, that can be found on the streets of my home town.

When I bought the charger I had the intention to try use it in a CubeSat project but after testing it I realized that its own batteries can not be charged using the solar energy.

Maybe I am doing something wrong. Maybe you can help me with an advice.

I would like to use the solar part of the charger in a cubesat
**broken link removed**
(for a demonstrative picosatellite, not one that will really go in orbit) but for the moment I do not know how to overcome the problem I have with the solar cells. I put aside 500 $ to finance my cubesat. It looks like 25 dollars are already wasted.
 
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Your solar cells may be too small for the batteries; you don't mention their voltage output, or current output...? For that matter, what batteries are you using, anyhow? You're asking a question, but not giving us enough information to help you. Finally, you don't mention a blocking diode (world's simplest charge controller - if you were actually making a cubesat, you would want a real charge controller in the design); if you don't have that part in place, when the sun goes down, the batteries can discharge thru the solar cells (potentially ruining one or both)...
 
The only information I have about the charger is its Model Number: CH-4632-ECO. It looks like any ordinary battery charger used for digital camera, excepting the fact it has two solar panels (3 1/2 X 1 1/2 inch each).
It charges 4 batteries AA NiMH, 2300 mAh, 1.25V type "ECO trends".
Picture: **broken link removed**
 
Not sure if this would work, but have you tried hooking a multi-meter up to it (instead of batteries) to verify that there is a voltage being generated by the solar cells? Also, how does that voltage compare to when you plug it into the wall? This of course assumes that the charger doesn't somehow sense a battery connected and only charges then (hmm - if so, maybe you can fool it by putting in only 3 of the 4 batteries, then checking with the meter on where the fourth should go?).

I wouldn't be surprised if it is either broken, or "fake" - or just a crappy design. I have a Harbor Freight Solar Shed Light with a panel that is supposed to charge 4 NiCD or NiMH batteries, to allow you to have a small light (flourescent) in your shed at night; needless to say, its never worked (and I haven't gotten around to finding out why, yet)...

:)
 
The only information I have about the charger is its Model Number: CH-4632-ECO. It looks like any ordinary battery charger used for digital camera, excepting the fact it has two solar panels (3 1/2 X 1 1/2 inch each).
It charges 4 batteries AA NiMH, 2300 mAh, 1.25V type "ECO trends".
Picture: **broken link removed**

That looks FAR too small to be of much use, although perhaps leaving it out in BRIGHT sunlight for a few weeks 'might' charge them up?.
 
maybe you can fool it by putting in only 3 of the 4 batteries, then checking with the meter on where the fourth should go?
For the moment I do not have a multimeter but I will have one next week. I will try to do the measurements indicated by you: 1) check if the solar panels generate some voltage, 2) check if their charging or short circuit current is not in the order of magnitude of micro Amps or below.
Thank you for your help.
 
Just based on the size, the thing pictured is a toy!
 
Your charger will only develop 0.25 Watts in bright sunlight.
Typical AA batteries are 2AH at 1.3V which is 2.6 Watts for 1 hour
Four of these would be 10 watts for 1 hour.
To charge four flat AA batteries would require 40 hours of bright sunlight!
I suggest you chuck the charge and get a real mains charger
 
What a Gimmiky item, the things people sell nowadays, im surprised companies are even allowed to sell these things.

I see loads of these thing knocking about and people run them down because there crap, then when someone comes up with a good solar idea, its automatically seen as crap like the other solar panel toys.

Rant over
 
What a Gimmiky item, the things people sell nowadays, im surprised companies are even allowed to sell these things.

I see loads of these thing knocking about and people run them down because there crap, then when someone comes up with a good solar idea, its automatically seen as crap like the other solar panel toys.

Good solar ideas are large and expensive - pretty well anything cheap is a toy or a con.
 
Today was a sunny day. I put the charger in full Sun (90 degree angle of incidence) and I measured Isc and Vo (no load) for each of the two 0.75 x 1.75 inch^2 = 8.47 cm2 panels.
I have found that:
Isc=3.3 mA
Vo=5.95 V
P_panel_max = 3.3 mA*5.95 V = 19.63 mW (2.31 mW/cm2)
for each of the two panels.
P_sun=135 mW/cm2 - known constant
In conclusion:
Efficiency_panel_max = 2.31/135 =1.72 %

Note: My initial estimation about the size of each solar panel was wrong. They are not 3 1/2 X 1 1/2 inch^2 but 0.75 x 1.75 inch^2
 
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