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Need advice and help for capacitor circuit design Answered

Hi all Instructables friends,
      I have been viewing instructables for quite some time and I like it very much, thanks to all the contributor here, I really learn a lot.
This is my first post here, and I only have basic electronic ideas, never soldier or build any circuit,
so please be patient if I made any stupid things :)

I have an idea in mind, not sure whether it is possible to implement or not, so I need electronic experts here to give their advice.

I have a very small palm size solar panel. need to build a circuit that can do the following :
1) The solar panel need to charge a small capacitor with a small capacitance, let say capacitor A
2) Then when this capacitor A is fully charge, it will charge capacitor B, which has higher capacitance.
3) The process of charging the capacitors with incrementally larger capacitance capacitor can continue to go on and on until some 
level that I can make meaningful usage out of it, for example, run a corei5 laptop. (most likely I will use super capacitor at the last)

My questions:
1) Is the above idea possible/feasible ?
2) If it is possible, will the capacitor lost energy very fast after some time?
3) I know people may suggest me to use battery, but I prefer capacitor or battery because battery life is very short compared to battery and it's not eco friendly either.
4) Any other concerns/warnings/advices are greatly welcome.

Thanks :D


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8 years ago

If you really want to go green you can get years of usable life out of a throw away car battery. Yes you can give a new life to an old car battery that will no longer start a car just as long as you use it in a low current application. Here is the link to the experiment I did a couple of years ago and it is still running led lighting today and every day 24/7 with an old car battery that would no longer start my car:


There should be a lot of useful information if you are using a solar panel so it might be worth reading all the posts in the thread. Also the part about re-using the old car battery is buried somewhere in the middle.

Good lux with you project.


8 years ago

Thanks for all the replies.

I was thinking of maybe using the laptop for an hour after a 1 to 2 weeks charge?

At the end of the circuit, I was thinking of having an ultra capacitor, would it help on the enormous power requirements?

My original intention is to make good use of that hand held solar panel because the rechargeable battery inside it was having issue with performance issue after over time. But the solar panel is still working perfectly.

My core idea is to collect electricity just like I collected water in a tank. Just that I don't know how to do that,

I think maybe the issues so far are :
1) Overcome the capacitor discharge issue, anyone have idea how to solve this?
2) Capacitor discharging too fast. Can this be solved by introducing some resistors?



8 years ago

I don't think it will work. I think the amount of capacitors you'll need to run a laptop will be absolutely enormous. I can't see any advantage to charging one capacitor from another. Also the leakage from the capacitor bank might exceed the power available from the little solar panel ?


8 years ago

How much use do you want to get out of the laptop?

That sized cell is usually better-suited to trickle-charging a mobile phone or torch, so you'll probably only get a very few minute's use from a laptop.

If you carry on, though, I would repeat your friends' recommendation of charging batteries - a capacitor can dump its charge quickly enough to damage the laptop's circuitry.