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Am working on a project which uses Solar panel to power the project. I have a 12v 5w Solar panel to use for this purpose. And am thinking to remove the battery from this project since I feel that application of this project is not very critical and it's enough for me to work only when the sun is bright and shining.

Apart from the above what are the practical problems that I can face when attempting to power a project directly eliminating battery. Here is the circuit I intend to power it using Solar panel directly enter image description here Also I was wondering whether underpowering these kind of chips from panel in non optimal conditions might damage the circuit and it's components. Is it a right concern? How can I identify a particular chip is susceptible to get damaged by doing this?

So far I have made an estimation that my circuit will consume 300ma. Any advice or suggestions please?

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    \$\begingroup\$ Are you, of course, using a 12V to 5V converter? And besides digital ICs, what is the rest of the system? In that case, I think that any problem could arise from the rest of the system (e.g. MOSFET or BJT used as switch, not being able to be fully ON, therefore dissipating power, when they shouldn't). Beside, to avoid this, you could add a "power-good" signal, that kills power in case of undervoltage. \$\endgroup\$
    – next-hack
    Commented Aug 24, 2017 at 7:38
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    \$\begingroup\$ Made the edit to show the main components of my circuit. "power good" signal? can you brief a bit about it please? \$\endgroup\$
    – Frank Donald
    Commented Aug 24, 2017 at 8:42
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    \$\begingroup\$ Some DC/DC converters have a signal that tells the rest of the circuit if the output is regulated. Typically this is called power good. (see for instance "special features" row in table here: ti.com/lsds/ti/power-management/step-down-buck-products.page#). Other have instead a under voltage lockout. They simply do not work if the voltage is under a certain threshold value. (You can also with a little external circuitry, generate those signal yourself). \$\endgroup\$
    – next-hack
    Commented Aug 24, 2017 at 8:58
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    \$\begingroup\$ Post schematic or no help. \$\endgroup\$
    – winny
    Commented Aug 24, 2017 at 8:59
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    \$\begingroup\$ 5W at 12V is only 416mA, so you haven't allowed a lot of headroom should a cloud drift across the sky. Don't assume a 12V solar panel will actually produce 12V. It's only a nominal voltage, and will depend on the amount of sunlight and the load current being drawn. \$\endgroup\$
    – Simon B
    Commented Aug 24, 2017 at 11:16

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C2 seems way to small for your consumption and the circuit will be very unstable. I would try to use at least a capacitor rated for 25V 10000uF. Maybe even several of these in parallel.

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  • \$\begingroup\$ Especially if the circuit is driving a motor, as the diagram suggests. \$\endgroup\$
    – Simon B
    Commented Feb 9, 2021 at 23:15

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