Automatic Solar LED Lights Repair
This article is about the cheap automatic solar LED lights that are sold in stores for less than 3 Dollar/Euro the piece.
Although they work great at first they stop working after a couple of months. And the period they simply quit greatly depends on how many rain has fallen in the meanwhile. Although these Solar LED lights, with mostly 4V white Leds, are well designed electronically they keep getting defect because rain drips into the Light housing and moisture oxidates the pcb, Led, battery compartment, and/or the switch.
Last year I bought a couple of new solar lights, to replace a couple of defect ones. And at that time I had about 12 of them perfectly working. But now a year later I had only 4 of them still working.
So it was time to check how many of them could be repaired. I had three different solar light models. Of which the oldest model only one had survived. They were unrepairable damaged because the transparent plastic top layer had deformed into a black/brown rimpled mass that stopped the sunlight from coming through. Removing the solar cells therefore was impossible too because they were melted into the plastic because of all the Solar heat in summer.
The 2 newer models are practically the same electronically, only difference was the rechargeable battery cell that was a replaceable mini penlight in the older model and a pcb soldered on type of NiMh/NiCad Battery cell in the newer model.
Of the last 2 models I hereby give the small and simple schematic that explains how they work :
I couldn’t find any markings on the 4 pins chip and both models seem to use the same kind of 4 pins chip. Only difference between both models probably is the small coil that can be a 100uH coil or even a 22uH coil. Needless to say that if the Solar Cell/solar panel is already gone, any repair will be futile. Or you must be able to use one available from another already partly defect solar light. One of my solar lights had a defect coil which I replaced by another coil almost identical. And I noticed that because it had a slightly different uH value, the Led gave a slightly different white color. But it worked without any problem and still does. Following photo shows the inside view of one of the newer solar light with replaceble NiCad/NiMh mini penlight.
Previous photo showed only little moisture damage, but already the oxidized battery holder is noticeable. Mainly because I already had previously, immediately after I bought these lights, glued the openings through which both (yellow and red) solar panel wires enter the housing to prevent rain from dripping inside. Sadly still already three of them are defect because the solar panel on top in itself may have been badly incapsulated into the housing. Those Solar Cells gave no voltage anymore.
These reddish brown solar cells are probably of the kind that are remanufactured from recycled solar cells also used in solar operated calculators. Not the expensive monocrystalline, or the cheaper polycrystalline cells. Or leftover cut-off parts from largers cells.
Another problem that moisture causes is that the flexible copper wires inside the lights blacken and almost are not solderable anymore afterwards.
Above photos show both newer models that have almost identical electronic parts.
It really is a shame that these electronically well designed solar lights have such a limited operating life. If the manufacturers only would make better moisture closed housings. Than I wouldn’t have to buy new solar lights for years to come. So this article is also a plea to the designers not to spare money on a good rain safe design!
But probably because most manufacturers are nameless or just unknown this will remain to be a problem. Normally only the strong electronic names will survive but not when many unknown firms make them this crappy for almost no costs. I finally will show both mentioned boards with some close-ups. First photo shows a board of which the led wires where completely corroded. Something that only can be prevented by spraying them before use outside with plastic spray. Same thing goes for the 4 pins chip legs. Which also corrodes very easily, and I already managed to repair a couple of them that had completely rusted of their legs. By using a small file and after soldering thin (0.1 or 0.2mm) wires to them glueing everything together with superglue to prevent any mechanical stress on the new made chip connections.
Previous photo showed how both solar panel wires enter the inside through the top. Which I had isolated with some glue and/or hot glue.
I hope many readers also will be able to repair some if not all of their defect solar lights. Not having to buy new crappy produced ones is also a good sign to the manufacturers to stop making rubbish.
I wish you all bright lights on dark nights!
Albert van Bemmelen, Weert, The Netherlands.
Please give a support by clicking on the social buttons below. Your feedback on the post is welcome. Please leave it in the comments.
P.S- If you enjoyed reading this, click here to subscribe to my blog (free subscription). That way, you’ll never miss a post. You can also forward this website link to your friends and colleagues-thanks!
Note: You can read his previous repair article in the below link: