Spli Positive System with Led Charging Feedback

[SkyWatcher123]

Hi all, while testing this latest circuit, i was not happy with the results i was seeing, so i am running the 12 volt bulb directly between the positives and that is showing better results.
So getting ready to start a fresh test run with that setup.
I have a 7 watt 12 volt led bulb i will try first.
The difference here is, I've never tried this type of split positive setup with the lithium ion cells and the lower voltage led bulb.
peace love light

[SkyWatcher123]

Hi all, the results so far are looking interesting.
The average watts used at any given moment over the testing period so far, is around 10 watts, since it is varying after each test run, as the input side progressively lowers in voltage.
The current flowing through the 12 volt 7 watt led bulb is around 900 milliamps.
I tested a single lithium ion cell to determine the amp hour capacity under a given load, I used 300 milliamps current to discharge the cell using my digital charger.
The cell was able to give 600 milliamp hours drained down to 3.6 volts, which is the voltage I have been draining the input series side to or 10.8 volts for the series battery pack.
That is around 2.25 watt hours available per cell or 6.75 watt hours per battery pack, when drained to 3.6 volts per cell.
The experiment has now run for 3 hours 16 minutes or 32 watt hours equivalent and the experiment is still not finished.

Though I am questioning if the input side, series battery is actually giving 6.75 watt hours capacity, since the current flowing is 3 times or 900 milliamps, compared to the 300 milliamps current drain used to determine cell capacity.
Since each cell in a series battery uses the same current, the actual capacity using this load, may be around half.

Well then, so far, if we assume each battery is giving us 6.75 watt hours capacity, which i doubt, i think it is less than that, then we have a total capacity of 13.5 watt hours, to run this setup.
Well, so far, the setup has used around 32 watt hours and the experiment is not finished yet, still has at least 2 or more good run times left i would guess and each run time down to 10.8 volts on the input side, has been around 50 minutes duration.
Your questions or comments are welcome.
Will continue with the experiment now.
peace love light

[SkyWatcher123]

Hi all, just wanted to add something else.
I forgot to mention, that before starting the test runs and battery swappings, I discharged one parallel wired battery pack for 1 amp hour.

So around 3.91 watt hours was drained from one of the lithium ion battery packs.

That means, since each battery pack contains around 6.75 watt hours of capacity or less, based on the 3.6 volt level discharge per cell, that is 13.5 watt hours minus 3.91 watt hours.
So we only have around 9.6 watt hours of capacity combined, to slosh back and forth in the split positive, swapping circuit setup.

I ran another run test, it ran for 22 minutes this time, so not much left to slosh back and forth, though I will test until a run time is less than 10 minutes and end this particular test.

So far, the circuit has operated for 4 hours 12 minutes or 42 watt hours and the 12 volt-7 watt led bulb load has used around an average of 7.5 watts throughout that time.
That is 42 watts divided by 9.6 watts for a total COP of 4.38
And the led bulb load used around 31.5 watt hours for a useable load COP of 3.28.
And technically, I can probably still squeeze at least another 30 minutes or more of run time.
Do these results sound correct to you folks, I've given all the data i have recorded in this particular experiment, what are your thoughts about this.
Gyulasun, would like to hear your opinion on this, did I miss something here or am i not taking something into account.
peace love light

[SkyWatcher123]

Hi all, I was recharging the battery packs and realized something.
When I drained 1 amp hour, from the battery designated to be the charge battery for the start of testing, I forgot that each cell in the 3 cell parallel pack, was drained of 1 amp hour or around 12 watt hours total.

The efficiency numbers I posted are too high, It's more like 1.85 COP total system efficiency and 1.4 COP led load efficiency.
I will make another test, this time, only discharging the intial charge receiving parallel battery of 4.2 watt hours or 350 milliamp hours shown on the digital meter.
Which, at an average of 4 volts per cell, that is 4.2 watt hours total from the parallel lithium pack.
That's all for now.
peace love light

[gyulasun]

Hi SkyWatcher,

Very good you spotted the mistake, I cannot be a fortune teller all the time...  (fun intended)

Hopefully your continuous, ardious tests give you valueable results that when repeated again, remain dependable and hopefully above unity.  Then take a rest and think over the whole setup, intial and final data.   

Greetings
Gyula