Charging 12V Battery with 10V Power Supply

[profitis]

Ah yes I see you know these secrets too.reminds me of those guys who recently announced usage of ions (silicotungstate) to undergo oxidation state change inplace direct gaseous evolution.I'm still trying to get my mind round your underpotential battery charger thing, you will get a faraday of deposition of lead from the bottom of the cells discharge curve climbing up until a point where you reach the 10v counter-zone..and then?dam mind-boggling

[Mancha]

Ah yes I see you know these secrets too.reminds me of those guys who recently announced usage of ions (silicotungstate) to undergo oxidation state change inplace direct gaseous evolution.

After gave up from loosing anode in my  1 V electrolysis project, I tried to change approach. I said to my self "why not lose solution instead loosing  anode ?"  Then I made my first big mistake in my research work. I was thinking that hydrogen peroxide is  answer for that, just unstable. I spent  too many working hours to make it stable without making  gas detection. I was upset by myself when I have found that there is no hydrogen at all. Just decomposition into oxygen and water vapor
So..we have to have that kind of mistake.
All The Best,
Milan

[mscoffman]

Mancha,

I think you are making a mistake with the 10.5 VAC transformer charging the battery. You generally can charge a battery
which has a voltage below it's maximum but the charging voltage always must be above the batteries current voltage. If you
hook a lower voltage source up to higher voltage battery you will force reverse current backward through the lower voltage supply
either blowing fuses, burning it out or folding it back.

The reason you are seeing some charging with the configuration of the 10.5VAC rectified supply is that a transformer is measured
in AC RMS voltage which is de-rated  .707 * volts(peak to peak) from the peak AC voltage so that means that the voltage
in total is about 14.8VACpk-pk = 10.5VAC RMS.  The diode blocks the lower AC voltages of the AC from being overridden by
the battery so that there is no backwards discharge flow (see above). So the battery is only conducting (recharge current) near
the peak = hence the altered AC power factor. These repetitive pulses are what is called PWM pulse width modulation so you have
only a small percentage of full current flowing that the AC line would be capable of for a short sub cycle period. This is what is
causing the slowing down of charging. Since you are being billed for less current by your utility meter is costing you less per unit
time but more units time should cause you to pay the *same* for this type of charging as the faster type.

I recommend the you get an oscilloscope and AC variac and you can see what the conduction charging pulse looks like at the transformer
as it begins to charge the battery as you slowly turn the voltage up.

To prove to yourself that the efficiency is the same at both charge rates you should set up a dummy load (headlamp) to
discharge the battery for the same amount of time then use your kilowatt meter to find the cost of charging the batteries
two different ways. You should allow so delay time for the battery to equalize after a fast charge. Another thing that would
help is learning how to use a hydrometer to detect the specific gravity of the battery electrolyte (see Wikipedia) so you
can start and stop the battery at the same chemical endpoints). If you can put the same specific gravity charge on a battery
at different rates then you might have something OU significant. But I predict the differences will be down in the noise.


If your really interested then you will need automate this process so you can integrate it a number of times without
procedural errors.

----

Now, you can electrolyze hydrogen slowly at a lower value of input voltage and room temperature heat gets included
as energy in the charge. Batteries also have this effect but it simply produces an efficiency effect that allows
a battery to charge with an efficiency that cancels out the batteries internal resistance, that really should be included.



:S: MarkSCoffman

[Mancha]

Mancha,

I think you are making a mistake with the 10.5 VAC transformer charging the battery. You generally can charge a battery
which has a voltage below it's maximum but the charging voltage always must be above the batteries current voltage. If you
hook a lower voltage source up to higher voltage battery you will force reverse current backward through the lower voltage supply
either blowing fuses, burning it out or folding it back.

The reason you are seeing some charging with the configuration of the 10.5VAC rectified supply is that a transformer is measured
in AC RMS voltage which is de-rated  .707 * volts(peak to peak) from the peak AC voltage so that means that the voltage
in total is about 14.8VACpk-pk = 10.5VAC RMS.  The diode blocks the lower AC voltages of the AC from being overridden by
the battery so that there is no backwards discharge flow (see above). So the battery is only conducting (recharge current) near
the peak = hence the altered AC power factor. These repetitive pulses are what is called PWM pulse width modulation so you have
only a small percentage of full current flowing that the AC line would be capable of for a short sub cycle period. This is what is
causing the slowing down of charging. Since you are being billed for less current by your utility meter is costing you less per unit
time but more units time should cause you to pay the *same* for this type of charging as the faster type.

I recommend the you get an oscilloscope and AC variac and you can see what the conduction charging pulse looks like at the transformer
as it begins to charge the battery as you slowly turn the voltage up.

To prove to yourself that the efficiency is the same at both charge rates you should set up a dummy load (headlamp) to
discharge the battery for the same amount of time then use your kilowatt meter

:S: MarkSCoffman

MarkCofman,
I agree almost with everything what you said, but it is also what I said on video with  my English.

Of course that we made test with scope, energy meters,  battery capacity analyser (we have four type of them).
also we always discharge  battery to the same level with the same current
For that we are using our energy meter :
https://www.youtube.com/watch?v=-9s2L5zjXjU

It is not something special, we just constructed for our needs.
Yes, needed time to make 100% charged  battery is longer than using ordinary chargers, but I said it in video .
But I do not agree that will be the same total invested energy. We got about 30-35% better results with 10V RMS AC , then with 13.5 V ordinary charger. the power factor is the same.
there are few reasons why it is better. first is how I described, another is lower current of charging. As you know higher current  decreases efficiency .
But it takes too much time.
It is not  invention, it is just one more approach for charging batteries.  I am using this principle in just  few cases in my lab. For some  cases I like to use this chargers  because is simple to make, no current  regulation, no nothing, just transformer and bridge rectifier.

All The Best,
Milan

[profitis]

 yes @mancha hydrogen peroxide H2O2 + 2H+ + 2e- >< 2H20  1.7v(Es) powerful oxidizer: H2 + H2O2 = 2H2O.did you know that virtually all intermediate catalytic-step reaction for the common O2 + 4H+ + 4e- >< 2H2O involves instant decomposition of h2o2 somewhere in the chain of steps.infact it involves so many short-lived intermediates that not even scientists agree on exact mechanisms yet.also different catalyst = different mechanisms. They got some electrolysis at 1.5v with Fe2O3 cathode and Ni(OH)2 anode just a few weeks ago but its actually been known since the 1960's yet they only shove this into the media now,very strange.I got visible electrolysis in my lab at 1.3v with platinum cathode and Nickel anode( in NaOH sol).I agree with markscoffman that when a non-gaseous (solid) faraday deposition is happening eg lead or zinc then how are you gonna jump over the counter-emf to get up to full capacity,solids cannot dissipate like gases or liquids do so I don't see chance for nernst manipulation? Only way I see to get round chemical counter-emf is via manipulation of voltage-peaks as markscoffman say but this will apply only to solids chemistry.a solid has a nernst-value of unity (1) beyond a critical point.