Driver for Garden Light

I have a question.
My Uncle asked me if i can help him with his garden lights. Its the type you put in the ground with a spike, 12V powersupply cheap white 5mm leds. No quite the contrary! The “bulp” is not cheap at all! They want 20€ for 1 :confounded: . So he asked me if i maybe can build something. Also he would prefer a much warmer light and a bit more output.
This is a picture of the bulp with only 3 working leds left. Everything is potted with epoxy.

My idea was to cut a copper disc the size of the old bulp. Glue a MCPCB with a 219C ( i have a few left in 4000K) on it and power the led with this driver
I have to test how much current i need to get him the prefered brightness (this driver is available in many different output current versions.
Is there a cheaper / easyer way to drive the leds? I hope to get more input and some other options to get him the best result.
In total he has 6 of this lights arround the koi pond.

Hi the TheOnlyDocc. Using the below Djozz chart as a general reference, it would appear the 4S 219C's without a driver would pull about 1amp and generate about 800 lumen. You could put a resister in series with the 4S 219C's to further reduce current/output.

Above from this thread.

I also modded some garden lights as I don’t like the blue leds and they die off easily. I would suggest you this driver:,searchweb201602_2_10065_10068_5731315_318_319_317_10696_5728812_10084_10083_10618_452_10304_10307_10820_532_5731115_10821_10302_5731415_5731215_5731615_204_10843_328_10059_10884_5731515_323_10887_100031_320_321_322_10103_5731715-5731415_5731315,searchweb201603_55,ppcSwitch_0&algo_expid=bd1de7d2-6e40-4cfe-94fe-8e0c64914232-11&algo_pvid=bd1de7d2-6e40-4cfe-94fe-8e0c64914232
You may want to change the solar cell and the batteries too. If you want to keep the 5mm leds you could have a look at the 5mm Nichia leds from They are the brightest I know (NSDW570GS-K1 28lm) and have 5000K (optional 3000K) white.

I have seperate lights. I want to mod each with only one 219C led. So i have to use some kind of constant current buck driver.
I will have to test a bit but i think max 500mA should give him enough light.
The MEAN WELL driver cost ~5$ shipped on ebay. But if i can find something smaller i could use the space to improve the heatdissipation.

Thanks Skylight. Was writing my post and have not seen yours.
The light is not using a battery. It is using a 12V powersupply and ~5m of cable to each light.
He has two sets (each set with a powersupply and 3 spike lights). The powersupply has a 12V 2A rating.
But like you said the original bulps are not lasting very long. The leds burn out very fast! The only good thing is, that the powersupply is strong enough to upgrade the leds.

Just thought they were cheap solar lights like they are often used in the garden. Recharge during the day, light in the night. With 24W of power for 3 leds you could confuse the fishes making them think it is day time. :smiling_imp: But yes, 500mA should do for the solar lights if you have six of them. Looking at Djozz’ chart you should get slightly above 1000 lumens then!

Why not just use a resistor with single emitter per light? A 22 ohm resistor rated for about 6 watts should bring current down to about 500mA. You don't need LVP or modes. I'm assuming the 12 power supply is providing DC (not AC).

I do not know how many Watts the Buck Driver would convert into heat (i expect a better efficiency from the buck driver) but the 3 resistors would produce ~15W.


Good point. I should have thought that through. .5amps x 9+volts = about 105watts for each light. That is a lot of wasted energy.

EDIT: Maybe you could hard to wire 3 or 4 of the lights in series so that you could use a much smaller resistor (if needed after resistance of wire run is taken into account)?

The powersupply and all connectors are potted. And the spike lights have a seal. After seeing the original box i noticed that this lights are (optional) made for using inside the pond.
You can remove the spike and put on something that lets the light flow on the water.
They are not used this way now but i do not like to cut wires that maybe are going into the pond some day.
I searched a bit more but did not find a better solution. When i get my sphere ready i will test one of the working bulps for brightness and then choose the right driver (something between 350-700mA) for the Nichia led.
But i really think that i end up with ~500mA. This way the lights are not getting to warm and they should be brighter than the old ones.