I placed many about - but have a lot left.
They come with an LED, a solar panel, and a 400ma battery (AA sized) (super weak battery) - but they are cool...
I have more than I can use, I took a few and opened them up and replaced the AA sized 400ma batt with some other 1200ma's and they were super brighter...
However.
I would like to harvest the parts from these solar lights (specifically the solar charging capability and attach them to a battery array with the solar array to a USB charging port as a way to learn how to do this.
Clueless.. I am seeking a mentor on how to do such, and I will send you a number of these devices to unlock yourself, but teach me how to harvest these objects and put them in series? to power / charge other devices.
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I have a few solar powered battery blocks, but I love the idea of using these little 1.5x1.5 inch solar panels to trickle a battery -- but more flexibly placed on something like a back pack or umbrella...
with the goal of teaching this to kids, but in this respect, I am a kid and would like to learn...
I don't know about creating a new series of either batteries or series of solar panels.
(In a backpack, what I would like to do is get a few replacement iPad batteries and have them slotted into a backpack and have the cheapo solar cells charge the ipad batts in the backpack...)
I have around 100+ of these $1 garden lights... (I couldnt pass up buying a solar power, a nimh 400ma battery and LED with controller board for $1 each...)
But now I am looking to a solution for the problem of having all these devices I want to build something else from.
Anyone tinker like this?
You will likely need minimum 3 of the solar cells in series to generate near 5V, maybe 4.
Then there is rate of charge, minimum worthwhile is probably around 250mA, maybe 500mA depending on what you charge.
Based on area and efficiency, eBay lookup, a 54x54mm solar cell is quoted at 2V, 100mA.
So allowing for efficiencies of conversion etc, then you need 3 series, 3 parallel of these cells to get close, running direct in a buck/boost convertor to make steady 5V 250mA under as wide a range of conditions as possible.
Maybe something like this https://m.alibaba.com/product/60841019812/DC-6-24V-12V/24v-t...
Though you might want to run more cells/voltage into it to maximise economy.
So a standard laptop USB port does 500mA, so you are looking at maybe 18 solar cells to replicate one laptop USB port capability.
Plus a one dollar part, and wiring and mounting.
So at $1 a solar cell capital cost that is around $8-10 per watt. (5 volts X 0.5A is 2.5W, $18 worth of cells, roughly).
If you go to AliExpress and buy any decent sized solar panel you can get them for under a dollar a watt.
If you buy the raw cells themselves and assemble them, because you have more time than money, under 25c a watt, maybe down towards 6-7c a watt - https://m.alibaba.com/product/1600163540077/Cheap-5BB-Polycr....
Interesting project, but totally uneconomical.
Edit, fixed up my costs in the starter config of 18 cells for 5V 0.5A