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Solar DS "Light" Redone and Improved

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The Nintendo DS Lite seems like it was made to have solar cells put on it. It has a large amount of surface area on the top and bottom that both face upward when the DS is opened. The top and bottom faces each have exactly the right amount of room for two 60x60mm solar cells side by side (four total). Each one has a maximum power output of 3 volts at 40 ma. The top two are connected in series and so are the bottom two. These two sets are wired in parallel to get a total of 6 volts at 80 ma, perfect for trickle-charging the battery.

My original instructable had a couple of flaws, some of them very important. I was originally going to post the updates on my first instructable, but there were so many changes that I had to make a whole new one.

Among these changes are:

  • Overcharge protection (the main reason I wrote a new Instructable)
  • Only one wire connecting the top to the bottom, not two little annoying ones
  • No wires around the edges
  • No annoying diodes where your hand goes
  • You can get the stylus out now (I accidentally put a solar cell over it the first time, silly me)

Another thing I need to mention is why I didn't use a 5v regulator and hook it up to the charging jack of the DS. The reason I did not do that is because I would have to rewire the solar cells to produce a higher voltage for the voltage regulator. This would give me less than 40 ma. Running that through a voltage regulator reduces that even further. Also, the DS would have its charging LED on if I did this. That would suck about half of the remaining current, leaving next to nothing for the battery. If I did it that way, the battery would charge about 4 times slower.

This is my third Instructable, and if you have any questions, don't hesitate to post a comment! Don't forget to rate and vote either!
 
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sxa2udo1 year ago
i like your cat
I'm planning on using AA's instead of the lithium pack. I've tested that my GBA SP works with it but need to test how many batteries I need for my DS.
Each Battery is is 1.5V, capacity of about 2200 mAh, which in my setup (3) gives me 4.5V @~6600 mAh. I'm planning on doing the solar panel thing for my SP, as well as making a USB interface as well. (Which works for the SP but not DS, probably not enough power, IIRC USB only provides 5V at 500 mA)
dark sponge (author)  double-helix2 years ago
If you put the three AAs in series, the voltage increases while the overall current capacity remains the same. In your case, it would be 4.5 v @ 2200 mAh. If you do need 6600 mAh, you can use nine batteries, with three sets of three that are in parallel. Other than that it sounds fine.
eddhewett2 years ago
Hey :D

I know this instructable's a bit old but hopefully your still around to answer yet more questions :P

Thinking of implementing small solar cells into multiple gadgets and came across this:

http://www.dealextreme.com/p/si-solar-cell-panel-4-5v-5ma-12984

WOW 4.5V out of something so small ! but wait, theres a catch, the current is only 5mA :(

So my question to dark sponge is:

How important is the current in the process of charging small gadgets ? Would the lack of current be a worthy sacrifice for the extra voltage ?

If that ones a no goer than I do have a second solar cell in mind with higher current so no worries.

Cheers dude !

Edd Hewett
Ok I think ive got more to add actually :P

As I understand it (which is not very well) the Voltage is the amount of electricity and the current is the flow of electricity, so the 4.5V cell with 5mA current could charge a gadget (say a mobile with a 3.7V battery) on its own but really slowly. Whereas with a 2V 25mA cell you would need 2 cells to generate enough V to charge the phone but it would charge a lot quicker as it has a lot more current.

So. . .

Would it charge 5 times quicker as it has 5 times the current ?

I am assuming current does not stack like V so if you were to include both the different cells in series the result would still only be a current of 5mA and not 30mA. Is this true ?

Cheers

Edd Hewett
One way to think of it is like water in a tube, Voltage is like pressure, helps to push the "water" (electrons) through the parts and pressure is lost to them like in frictional resistance, thus the main purpose of resisters is to lower voltage, and current is the flow. You can add voltage(but not current) by making them in series or add current(but not voltage) by adding the power source in parallel. Each part generally needs so much pressure and flow to work but not too much or your figurative pipes will break or overheat from friction, such as a fuse will blow if the current is too high. So basically they need to be within a threshold to get it to work and below the point where it will fry your parts so just adding more current doesn't mean it will charge faster, it might break it. though from the looks of it the higher current set looks to be the better option and though I don't know for sure should be a safe current. hope that helps.
ilithis2 years ago
Hey guys, I was wondering if there would be any negative effects if I used a solar panel that outputs 5.5V instead of 6V (afaik that shouldn't be a problem), but the current output for this solar panel is 180mA. My DS Lite has a 1000mAh battery and I was wondering if that is too much juice when charging the battery or will the battery just charge faster?
dark sponge (author)  ilithis2 years ago
It should not harm anything because that is still a relatively low current for charging. 5.5 volts should work fine as well, as long as it is a decent amount above 4 volts. Have fun!
zombeastly2 years ago
lets do it for 3ds next!!!
Steppenw01f3 years ago
Hi, I got stuck at the final testing part, when I touch the multimeter's positive terminal to B- and its negative terminal to the negative battery wire, the voltage spikes to around 2 volts then drops back to 0. When I solder the negative wire to B-, the DS doesn't turn on either. If I touch the negative terminal to the positive battery wire and back to the negative battery wire, it repeats the same behavior. I've checked my wiring repeatedly, everything seems fine as far as I can tell. FYI I'm using the PV cells, overcharge circuit, and diodes you listed on my original DS.

Any help would be greatly appreciated.
Thanks.
dark sponge (author)  Steppenw01f3 years ago
Hmm, strange. Try bypassing the charge circuit by temporarily connecting B- to P- and B+ to P+, then see if it turns on. If it does, something might be wrong with the charge protection chip. I'm curious as to what the problem could be here.
Messed around with it some more and it turns out the DS wouldn't turn on even with the battery directly plugged in : (, but I wired the battery back to the circuit and the circuit to another DS and it turns on fine! I'd test it right now, but it's rainy here and the forecast says it won't be mostly clear until at least Wednesday. I'll be sure to post a pic when the sun comes out.

Thanks for the advice and awesome guide!
dark sponge (author)  Steppenw01f2 years ago
You're welcome, I'm glad to hear it's working!
I just set it up on my SP also, can't wait for a sunny day!
could this be done on a netbook?
dark sponge (author)  Daniel Deacon3 years ago
Probably, but with the bigger battery you would want to be more careful. Also, if you were using higher current solar panels you would probably want to have a Li-ion charge circuit instead of just an overcharge protection circuit, because Li-ion batteries are picky.
cherylcaleb3 years ago
i'm really interested in solar panels n their uses n i'm 12. My allowance obviously aint high enough. Wats the cost of this project n is there some cheaper method??????
dark sponge (author)  cherylcaleb3 years ago
Do you mean large solar panels, like for powering a house, or solar cells for small gadgets? If you are looking into panels, try to find packages of cells for cheap and build a panel. I don't really know where to find cheap solar cells, but the ones used here weren't very expensive for the small amount I needed.
mreginello3 years ago
Is it possible to put the entire rig onto a DS case? That way you can use it when needed?
dark sponge (author)  mreginello3 years ago
Probably, but you would still have to have wires go into the battery compartment unless you add a separate battery and voltage regulator to use the charging slot.
ZeroXL913 years ago
Wait, so like that guy said, is it possible to have a battery that can charge with solar and DC power?
I need to reduce the voltage down to 4.5 or 4.6 volts for the DSi, any suggestions how I can do that....
dark sponge (author)  winter-chaos3 years ago
It would probably be fine with 5 volts but I woouldn't risk it. You could look into circuits using an adjustable voltage regulator. It's similar to a 5 volt one but you use a set combination of resistors to set a specific voltage.
thanks that helps alot, ^^.
technoguy943 years ago
Is it possible to make a DSi version?
dark sponge (author)  technoguy943 years ago
Probably. I discussed this in some old comment thread, but that's probably buried deep under the recent comments. You would have to drill a hole or move a panel to not cover the camera, and the battery has three terminals (I think one's a thermal sensor?).
I was wondering the same thing... if you just hooked it up to the end of a ds charger you'd be able to use solar power and normal wall charging... just a thought for ANOTHER redo :P
dark sponge (author)  ShadowAssassin3 years ago
Actually, there is already an option for a charging base in step 17. Also, even with the panels on the DS , you can still continue to charge it with the charger if you need to.
Nice kitty
dark sponge (author)  stargazer4185 years ago
His name is Ferris.
Hey Sponge , im 24 , & i think im going to do this.this week.for somone who doesnt know much about wiring and who's soldering skills are minimal . do you think i can do it? cheers.
dark sponge (author)  fernxtwo5 years ago
Probably, I'm only 14 and I managed to come up with this idea when I was 13.
14 years old, nice. This sounds like something i would have done if solar cells were cheap when i first learned to solder, i was about 13 or 14. (Almost) Everybody should learn to solder.
dark sponge (author)  Metal Crave5 years ago
I agree, everyone should know how to solder.
Yes...and everyone should let everyone solder... Apparently not...
well I'm 11 and I don't know how but I want to learn
dark sponge (author)  soaponarope4 years ago
You should, it's a very useful skill for anything to do with electronics.
i know how, but i'm too cautious and it scares me. tape, anyone?
The idea of messing up on your own precious DS is a scary thought, but that's where practice comes in.
Knowing what you're doing is the best tool you can ever have.
i did it to mine , and have had it for the last year or so. but it adds wayyyy to much weight to it.and i have found myself not playing for that reason , i'm gonna take it off pretty soon.
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