Rechargable batteries are a great invention, but if you dont have an outlet nearby to charge them, they are usless. So I designed a solar powered battery charger, which allows you enough power to charge a single AA battery wherever the sun may shine.

I chose to do this project in two steps:
First I set it up to test that I generated the needed voltage (3-7).
Then I set it up to finalize, by using wire instead of alligator clips, this made it both look better and was easier to work with (8-10)

People have told me that 1 volt is not enough to charge a battery. I looked a rechargable battery and it said "charge: 1-2 volts." I would also like to add that I switched the tester to 2.5 volts and the meter moved to 50%. This tells me I do not only generate 1 volt, but 1.25 volts give or take...

Step 1: Materials

Here is a list of the Materials you will need to recreate the Battery charger I have made,
-Light socket attached to wood (with outlet plug)
-100 watt bulb
-Hot glue gun
-Two solar panels
-Three alligator clips
-Rechargeable AA battery
-Voltage tester
-Battery holder

Once you gather your equipment, I suggest plugging in your Hot Glue Gun, so it is available to you once needed (Step 4)
Could this be expanded for more than one battery say like up to 10 of them?
<p>You could charge more batteries, but they would have to be in parallel...HOWEVER it would take much longer to charge all ten of them with the current setup of the solar array...which means that you would have to add more solar panels to the array.</p>
go and get a 12v solar panel (13x30cm approx) and a diode and then you can charge up to 10 at a time(only in direct sun) 500mah 180 min 600mah 200min 700mah 230min 800mah 270min 1000mah 370min+ 1300mah 430min 1700mah 500min 2000mah 630min 1.2ah drill battery(9.6or12v) 6-7hours
<p>You should add a blocking diode between the solar array and the battery to prevent the battery from discharging in low light or when there is no light. Nice project nevertheless!</p>
how do u know when the battery is charged
Hey i just had two questions.<br>1. When the battery is charged will it over charge and kill the battery.<br>2. How many volts does both of your solar panels make.<br>please reply i really want to make this <br><br>
Does this, or any of these solar battery chargers, work on (3.6v/3.7v) lithium-ions? With or without PCBs? Thx
VKelectronic has several very cool solar rechargers<br /> <br /> <br /> http://vkelectronic.freei.me/New_products.htm
Do the solar panels have built in diodes?
if you add a diode it will prevent battery from draining and going flat.
Indeed, a simple diode would improve this a lot.
what is this it needs more work
This project doesn't need diode??
oops!! also different sizes aaa-d?
1V is not enough to charge this type of cell, you need something more like 1.5V. Have you tested this and found it to work? L
even more to overcome internal resistance
No load my NiMH's are giving me 1.38V, so I'd say you need to be able to manage1.5V at least. Next time they need a charge I'll see what the charger is giving them. L
No diode to prevent back flow? When your battery is charged AND the solar panel is in the dark, the battery will actually start discharging INTO the solar cell. Just put a simple diode like a 1N4001 between the +ve terminal of the solar cell and the +ve terminal of the battery - the cathode (white stripe end) of the diode towrds the battery.

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