Hello, I am new to solar and am designing a solar battery charger. At the moment, I would like to use a 7.2V solar panel with 100mA output, a 1N5817 Schottky diode, and a 5V voltage regulator and resistor for limiting current to 100mA. I would like to charge 3 x 1.5V batteries. I have a few questions about things which Im struggling to understand:
1. Assuming the panel is rated at 7.2V and 100mA output, does this mean that the maximum possible output of the panel can never exceed these values?
2. I have seen some battery charging circuits which use a voltage regulator in series with a resistor to limit current. Assuming the panel cannot output more than 100mA, is there a need to use a voltage regulator in series with a resistor at all?
3. Assuming a constant panel output of 7.2V and 100mA, is this an appropriate panel with which to charge 3 x 1.5V batteries? And does the remaining power 0.1*(7.2-4.5) dissipate as heat?
4. Will there be negative effects if there are fluctuations in the level of solar irradiance? I suppose that if the panel outputs less than 5V (due to clouds or shading), the batteries would simply stop charging, but would this result in battery damage if the charger was repeatedly turning on and off due to changing light?
5. Will the batteries all be charged by an equal amount, assuming they are connected in series? I mean will I ever find that one battery is charged significantly more than the others, assuming they are all in the same condition?
Thank you kindly,
Andy
1. Assuming the panel is rated at 7.2V and 100mA output, does this mean that the maximum possible output of the panel can never exceed these values?
2. I have seen some battery charging circuits which use a voltage regulator in series with a resistor to limit current. Assuming the panel cannot output more than 100mA, is there a need to use a voltage regulator in series with a resistor at all?
3. Assuming a constant panel output of 7.2V and 100mA, is this an appropriate panel with which to charge 3 x 1.5V batteries? And does the remaining power 0.1*(7.2-4.5) dissipate as heat?
4. Will there be negative effects if there are fluctuations in the level of solar irradiance? I suppose that if the panel outputs less than 5V (due to clouds or shading), the batteries would simply stop charging, but would this result in battery damage if the charger was repeatedly turning on and off due to changing light?
5. Will the batteries all be charged by an equal amount, assuming they are connected in series? I mean will I ever find that one battery is charged significantly more than the others, assuming they are all in the same condition?
Thank you kindly,
Andy