I was in the dollar store the other day and saw this tiny garden rock, once I looked closer I noticed it was more than a rock. It was a solar garden light. It only costed one dollar and out of curiosity I had to buy it. I was browsing the web the other day and came across a product review for a solar recharge flash light. A lot of the reviews claimed that the solar panel was fake. Now I bought this rock just to see if the panel was real. Stpid reason? Sure but hey I was curious. After I got home I quickly took it apart to find out it was indeed real. It was a small panel and produced 2.5 volts at whatever Mah. After testing its various componets I realized I had no purpose for it. No garden and if I had one, one rock would make it look sad. I modded the circuit a little bit and turned it into a suprisingly bright solar rechargeable flash light. Also for a dollar this rock light was very well made. I will show you how to turn this rock light or any garden light into a nice flash light. If I may borrow a few minutes of your time lets get started!

Step 1: Taking apart your garden light. Well my rock light. all similar

Take apart your light and disconnect everything. I just snipped the wires to later use them as a guide when re-connecting. 
If you happen to find the exact same light I have then this should be easy, if you are using a different light then it might be a little harder, depending on what brand. Some make others more secure and what not. 

In the picture you will see a small circuit, a small 1.2 volt battery at 40mah, a small solar panel and a led/reflector. All pretty simple. Now before you ask, there is no blocking diode in this circuit. It was designed to not have one. it works the same as it would with one. 

Who as ever heard of 40mah battery? So tiny. I think we can do better. Since it is rated at 1.2 volts alls you have to do is replace it with a rechargeable double a battery. Most rechargeable double a batteries are rated at 1.2 volts aswell. I upgraded to a 500 mah battery which may sound like a lot but trust me it really isn't. It is however a great battery for this project since it is just powering one led. Now Im sure some of you new to electronics are thinking "wait, 1.2 volts? How is that going to drive a white led normally rated at 3 volts?" If you haven't noticed almost all garden light operate off of one battery rated at 1.2 volts. Now how it runs the led lies within the circuitry. Most circuits will have an ic or an inductor. More than many will contain an inductor or two. The inductor is what helps boost the 1.2 volts into enough to drive the led. Here is something else, if you change the value of the inductor you can either make the led brighter or dimmer. I ended up changing the value of the inductor so it can make the led brighter. You might not have to do this with other lights. Some, i am sure are brighter than others but if yours is a little dim you can simply make it brighter! I will get into that in a bit.
Got a couple from the store but the batteries were almost gone. You have to be real careful removing the glue so the solar cell does not get damaged. Also thinking of putting a microcontroller in the rock for some fun.
The battery was made in this one. Yeah the glue was an issue, i had to be really carefull. What would the micro do exactly?
Very cool! My friend just had a wedding and these were lining the drive. They got cruhed during the night, i collected them (20 or so) and wondered what to do with them. This will be a great project!
Thanks for the kind words! From crushed lights come new night sights! Let me know how they turn out :)

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Bio: My name is Taylor, Im currently going to school for electrical technology, going to school for what I love. I have been in love with ... More »
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