# Capacitor Battery Charge Circuitry

Just a forewarning I am a complete rookie when it comes to capacitors

I am looking to supply a 0.5mV charge into a capacitor, then have the capacitor discharge to a battery once the accumulated charge reaches 4V. Once the stored charge on the capacitor is below 4V, the capacitor should store the energy again until the accumulated charge reaches 4V to repeat the cycle listed above.

So basically I am looking to have a low voltage input into a capacitor, and have the capacitor discharge to a battery only when the stored charge is above 4V. What type of circuit is capable of this task? Will just a super capacitor work?

• It doesn't make sense that you are supplying 0.5 mV into a capacitor and expecting the voltage to accumulate. Might you supplying a CURRENT of 0.5 something into the capacitor rather than a voltage? In other words, what is your source of power? Mar 24, 2015 at 21:50
• Assume my source of power comes from a generator which outputs a very low current such as 20mA or a power output of 1mW Mar 24, 2015 at 22:02
• 0.5 mV is a voltage, not a charge. If you connect 0.5 mV to a capacitor, it will then have 0.5 mV across it, which is never 4 V. How are you "accumulating" these voltages? Mar 24, 2015 at 22:46