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Home  News Latest Solar Battery Charging
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Tuesday, 20 March 2007 |
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One of the simplest DIY solar projects is to make your own solar battery charger using a small Photovoltaic (PV) solar panel.
Only a few readily available components are necessary for this project:
Rechargeable batteries - AA or AAA sized. $2-4 each.
Plastic battery holder with leads. $0.40-$1.00
One diode. $0.10-$0.20.
Solar panel. $depends on size Building a Solar Battery Charger Pictured above is a battery holder for one AA battery. These battery holders are available in a range of sizes from 1 AAA to 4 AA batteries. Use the one which is suitable for your needs. The size of the solar panel required depends on the number of batteries you intend to charge and on their capacities. Note that all batteries charged at the same time should have the same capacity. Each rechargeable AA or AAA battery is rated at 1.2 volts and needs a charging voltage of around 1.4 volts to reach full capacity. Therefore if you want to charge 4 x AA batteries you would need a 6 or 9 volt solar panel. Select a Suitable Solar Panel To decide the current you require, you need to add up the capacity (mah) of each battery - for example, if you would like to charge two 2200mah AA batteries, the total capacity is 4400mah. You must not charge a battery with more than 10% of its capacity as current - i.e. in this example the current should be less than 220ma. If you break this rule then overcharging can occur damaging the battery potentially beyond repair and generate heat. Therefore to charge one 2200mah AA battery, a panel generating 200ma of current at 3 volts would be perfect.
A diode is used to prevent the batteries' charge being dissipated back through the solar panel when it is dark. The circular band around the diode should be positioned at the negative end of the circuit. A 1N5817 diode is perfect for the job as it only 0.2 volts is lost as the generated electricity passes through it. If you have a Germanium Diode these are also excellent.  Putting Your Solar Battery Charger Together Assembly could not be easier. The battery holder will have two leads - one red and one black. The solar panel will have two leads - one red and one black. Connect the red leads to one another with solder or just twist them together. Connect the black leads to one another in the same way. Put the battery(ies) into the battery holder and put solar panel in direct sunlight - inside on a window cill or outside if you prefer.
Sorce: www.reuk.co.uk - Solar-Battery-Charging -19th Feb 2007 No one has commented on this article.
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Last Updated ( Wednesday, 21 March 2007 )
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