Our community bought a solar powered entry light several years ago. The controller went belly up as well as the panel. The controller was pretty much a horrible design so instead of trying to fix it, I designed a new controller. I also replaced the solar panel and battery, choosing larger sizes for both.

It has been a huge success. It has been almost 3 years now and I have yet to replace the battery (though I think that day is coming soon). We used to replace the battery on the original design about every 6 months.

At the time I did not replace the light. I am thinking I want to do so now. I want to keep the original housing and just replace the LED panel. The question is how to do it?

The current light has an array of 108 LEDs . It operates on 12V @ ~640ma. There are just 2 pair of wires (12V and ground) going to the light. The light is driven by a Luxdrive buckpuck that also supplies 5V for the pic.

I would like to keep the specs roughly the same so I can plug and play. Should I replace with another array 108+ LEDs ? Or should I move to the Cree type LEDs?

One problem I understand is LEDs in an array should have their forward voltages match? So the more LEDs the bigger problem with matching LEDs.

The problem with the CREE type lights is I would need to have a heat sink?

Any ideas?

Also any inexpensive reliable source of LEDs?

I do have few of these around but have no specs on them at all. I am not sure what their current requirements might be.

Some other pics from my project that is in place.

I've been tinkering with LED lighting forb a while and would suggest a large single LED with heat sink and a fan instead of a lot of small LEDs. Part number G19653 from Electronic Goldmine. 9 to 12 V, about 1 Amp, about 900 lumen, 10 Watt.

 

Fan? Very high probability of failure and or other trouble. IMHO, a bigger heat sink is a better option than using a fan. Fans tend to get noisy, inefficient as they get dirty, and venting is more likely to clog with the increased air flow while it does work. A larger heat sink that you can easily clean is a much better option for long trouble free life. Also, I like to use about 70-75% of the rated current of the LED, also to extend life as it keeps the heat down a bit. You don't get enough additional light when you run at full current to justify the extra power consumed. Again, opinion, but so far, I have not had an LED fail with this philosophy.

 

Fan? Very high probability of failure and or other trouble. IMHO, a bigger heat sink is a better option than using a fan. Fans tend to get noisy, inefficient as they get dirty, and venting is more likely to clog with the increased air flow while it does work. A larger heat sink that you can easily clean is a much better option for long trouble free life. Also, I like to use about 70-75% of the rated current of the LED, also to extend life as it keeps the heat down a bit. You don't get enough additional light when you run at full current to justify the extra power consumed. Again, opinion, but so far, I have not had an LED fail with this philosophy.

It sounds like you know what your doing then. Keep us posted on what you decode.