Electricity In Series Saved For Reuse, Conserving Energy?

 12v lead acid battery is hard to deal with for exact readings of energy transfer, and release. The charged battery has certain quantity built up of pluses + and minuses - at each end, so as being unbalanced. The discharging of battery is seeking balance of charges. A large computer capacitor is readily available and responds to electronics math formulas. See 2 manuals from Eagle Research called Energy Conserver. A quality polypropylene capacitor is NOT an electrical load, only a temp storage means. Electricity passing over wire to resistive load such as lamp bulb releases light as work done. If opposite end is connected to capacitor, the in series current is absorbed into it, held, with quantity of electrons, not passing on to end connected battery terminal. If 2 caps are in parallel (with switches) and in series with other side of source power, the light stops at point, that volts match. The 2 caps are then put in series so as with higher volts. The main power source is disconnected. The storage of same used current is rerouted back through bulb. The 2nd work done brightness can be measured as close same with lumens meter, and at approximately same time value in seconds. Question- Does this bench test require power factor reading? This system could extend range of electric cars, or create more Hydrogen gas from water cells.        

I'm not clear what you mean by "used current." A load such as a bulb only draws as much current as it needs from the power source. There is no leftover energy to recycle -- it has all been converted to light and heat.

There are a lot of advanced hobbyists making capacitor storage units. A search should turn up many plans designed by skilled builders.

A capacitor does not "absorb" DC current. If you place a capacitor in a series circuit with a battery as the power source, nothing will happen after the initial inrush of charge is accumulated, and this takes microseconds. After that, it is a purely blocking device -- hence their very common usage in AC applications to prevent DC from appearing in places that it shouldn't. Discharge is a similar scenario: after the rapid energy release into a load, no current flows and the potential difference across it is zero.

The "used current FIRST passing through lamp is interrupted before meeting battery return terminal and is stored in capacitor. The battery is still unbalanced without having those electrons. Capacitor then runs the bulb second time, with stored energy it used the first time,  without primary power source, as it was disconnected. You can do this yourself with 9v battery, bulb, jumper wires, meters, stop watch in seconds, small uf capacitor, same lamp brightness, etc.

Ok, but we should be talking about the energy stored, because there is no usable current to speak of. A certain amount of work needs to be done to push apart positive and negative charges and place them into the plates of the capacitor. Now they have stored energy because they are sitting at a voltage potential that can do that same amount of work minus dissipative losses. Unless you're dealing with banks of supercapacitors and high-impedance loads, that work will all get done very quickly and the current flows in whatever circuit they are powering are going to be short.

Yes, that's what capacitors do -- store and release energy. No more energy is created -- it all comes from the initial source.

The problem with capacitors is that they self-discharge internally.

Developing capacitors that don't self-discharge is the subject of intense research. If someone can get it right and get it into production, they will become insanely wealthy. But it remains a dream at this point.

EDIT: Oops, Phil beat my post by 10 seconds. I was responding to the OP.