I'm going to discuss a measurement issue that came up from Aaron's comments in the Bedini 10-coiler thread on EF.
Fist Aaron said these correct comments about using voltage on batteries as a way of determining if you have over unity or not:
That is a tired and worn out argument. Those that know what
they're doing do not simply use voltage that shows up on a meter
to see how much energy there is. Work is drawn from the battery.
This has been repeated countless times and insinuating that this
is the method used to determine "overunity" is misleading and is
manipulation. Some people starting out will think voltage readings
means more than it does, I did in the beginning because I didn't
know better but this does NOT apply to those that have been
working on these projects for a while.
Then subsequent to that he made these comments:
Then turn off the machine and disconnect the secondary battery and
draw a load at the right rate (c20 is probably what most people will
scream about) and also with a current sensing resistor and do the same
data capture until that battery is down to the voltage where it was
before it received a charge. Use a resistive load on this battery instead
of an inductive load.
Aaron is suggesting this:
1. Measure the start charging battery voltage.
2. Measure how much energy you put into the charging battery
3. Discharge the charging battery at the C20 rate and measure the energy until the voltage reaches the voltage you measured in Step 1.
4. Compare the energy you put into the charging battery from Step 2 and compare that to how much energy you extracted from the battery in Step 3 to determine your COP.
The huge mistake here is that Aaron is using battery voltage, which is what he stated that you can't use in a posting that he made just one day before. I also am pretty sure that the Yahoo Bedini groups use the same method and that means all of their COP data is junk.
Here are the facts to consider:
A. The voltage on a battery is essentially the same for up to 90% of the discharge cycle. That simple fact right there indicates that measuring battery voltages is meaningless data.
B. When you charge a battery you will read a fake voltage that is higher than the real battery voltage due to the battery's charging input impedance.
C. When you discharge a battery you will read a fake voltage that is lower than the real battery voltage due to the battery's discharging output impedance. Depending on the discharge rate, you will read a different voltage.
The whole premise for Aaron and the Yahoo Bedini group's COP measurement for charging and discharging batteries is hopelessly flawed. You simply cannot pick an arbitrary battery voltage and charge and then discharge back to the same voltage. Logically it doesn't make any sense at all. Even the ambient temperature will affect the nominal battery voltage.
Somewhere in this thread or in the 10-coiler thread there is a discussion about how to make measurements to determine how much energy there is in a battery using load testing. You have to define a protocol for a given battery and stick to it. It's a lot of work and it takes discipline.
And I will repeat a comment that I have made before. Measuring the output impedance of a battery can tell you about the state of charge of the battery or the state of health of the battery. It is much more useful information than the open-circuit battery voltage. Experimenter's should learn how to do this so that they can get a better handle on their batteries. It has been mentioned several times by me and nobody ever says anything. It's a very useful tool and it is simply not discussed by the experimenters and I think that's a shame.
MileHigh