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Scrounging from a Solar Garden Light

Inside We have purchased several small solar powered path lights over the years. These little lights come on automatically at night for a few hours till their rechargeable batteries discharge then they recharge the next day to repeat the cycle. Eventually, far too soon in my opinion, they just stop working or stay on for minutes rather then hours. Rather then throwing them away, lets take a look at what might be salvageable for other projects.

Pictured here we see the insides of a used path light. there are some open holes in the plastic cover for mounting. These openings let bugs and grass get inside which explains the filthy contents. I am surprised that the electronics are in such good condition considering they were almost totally exposed. I believe this unit is over a year old.

 

InsideClose Pictured here is a close up of the small PCB. A plastic battery holder holds two NiCad batteries and provides mounting for a small PCB. The PCB has two bright white LEDs Two transistors, two diodes and several resistors. There is also a CdS sensor and a small solar panel mounted to the plastic housing.

Unless you are scrounging a new path light, the batteries are probably no good but there are several parts two scrounge.

  • Solar Panel
  • CdS Light Sensor
  • Battery holder
  • Two bright white LEDs
  • Two Transistors
  • The rest is probably not worth keeping.

I planned to keep the LEDs, the battery holder, the CdS sensor, and the solar panel. Turns out the solar panel is hard to remove. I cut and pried to the point I was sure the panel would break. Then I decided that it would be better to scrounge the complete solar path light as part of a larger project. Its a ready to go solar power system. Just remove the LEDs and tap the batteries for some other project. Maybe a Zigbee temperature sensor…

I put the pieces back together and stuck the thing, minus the batteries in the TGIMBOEJ box leaving from here this week. I hope someone can make good use of this. If I do a project where I need solar power I will buy a brand new one. I think they are inexpensive. More later…

Posted in Discovering, Ideas, Parts, Projects, Scrounging, Scrounging Parts. Tagged with , , .

7 Responses

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  1. MikeS said

    I’ve taken a few apart also. The problem is usually the batteries are worn out cheap junk.

  2. How about replacing the battery?

  3. “CCDS Light Sensor”. Do you mean CdS sensor?
    I would expect Cadmium Sulphide sensors not CCD Charge Coupled Devices.
    Sorry Just want to be a pedantic bore. ;+)

    Love the site but the nerd (troll) in me needs to have correctness.

    Matt B

  4. dfowler said

    @Ayush, where is the fun in that? LOL.. The lens on this light was so deteriorated I do not think it would have passed much light and probably would have shattered if I tried to force it back together. If you take care of these low cost garden lights, I am sure you could replace the batteries and get more life from them. This one had sat outside non functional for maybe a year. It may have been saved but I wanted to see how it was put together.

  5. dfowler said

    @Matt
    Yes it’s a CdS sensor. I meant to fix that before I published. I was not sure what the correct text was for the sensor so stuck in CCDS. I will fix the text. Thanks for being a “pendantic bore”

  6. @dfowler, I guess it wouldn’t be as fun. Even though I love to get parts from broken things, when I look at the circuit board I feel somewhat dissatisfied. I would much rather just spend the extra two bucks on buying the parts from mouser than get my desoldering tools out and take it aprart only to realize that the wires (leads?…w/e you call them) are too short to be actually used.

    From the picture it looks like you can just pop out the battery and replace it…

    But then again…if you don’t need it…*pulls out soldering iron* :p

  7. agw said

    A couple solutions to make them work again:

    1 – Before trashing them, try “zapping” old batteries with a big capacitor in order to melt those small internal crystal deposit that short circuit them in the long run. This applies both to NiCads and NiMh. There’s a lot of information out there on the subject.

    2 – Replace batteries and leds with newer ones. Newer batteries have a higher power density and more modern leds should give more light at the same power consumption, or the same light with less current.

    I’d also try #2 and making one lamp out of two by putting two solar cells in series or parallel (+ a diode, depends on the circuit). That should add much more juice to charge more powerful batteries.