# Silver Cell Cathode



## delboy9891 (Aug 21, 2022)

Hi Folks, I have checked through the forum and cant find anything for this, when my Silver Cell is running it generates a bit of heat, what I am wondering is if I place the cathode on a stainless steel tray in ice to keep it cool will it affect the running of the cell in any way ,thanks in advance for any advice


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## 4metals (Aug 21, 2022)

On larger commercial systems I prefer the cell to run warmer to cause evaporation and allow rinse waters to be re-introduced to the cell rather than treating them as waste. So I would not be worrying about the cell running warm.

And how would you place the cathode in ice and not the rest of the cell?


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## delboy9891 (Aug 21, 2022)

Thanks for your reply 4 metals, my Cathode is a 2.5 litre Stainless steel bowl, that would be the only thing going in the ice, the anode would be in an Anode Basket inside the Cathode, was just wondering if the Silver Cell would be more efficient if it was kept cool


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## 4metals (Aug 21, 2022)

delboy9891 said:


> my Cathode is a 2.5 litre Stainless steel bowl, that would be the only thing going in the ice, the anode would be in an Anode Basket inside the Cathode


Makes sense. I have never run a system that small but it would be easy for you to quantify to teach us all something. Make up enough electrolyte for 2 bowls (5 liters) and clean out the bowl and add a known quantity of anode (known surface area). And apply a constant amperage. After 24 or 48 hours running, shut it down and weigh the yield. If possible take it’s temperature half way through. 

Then clean it out and repeat with the second half of the electrolyte, the same anode material and surface area and the same amperage. This time cool it ( maybe with a slow flow of cold tap water flowing into and out of a shallow bowl the cell is set into). Then shut it down after the same time period and weigh the yield. Also take the temperature of this cell halfway through as well just to make sure you are actually cooling it. 

It would be interesting to know. It’s much harder to quantify on bigger cells.


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## delboy9891 (Aug 21, 2022)

Thanks 4 metals, I will try that and post my findings on the forum.


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## KalleMP (Aug 21, 2022)

To keep things scientific I would make the test with two as close to identical cells as possible and connect them electrically in series. The Coulombs of charge flowing through each cell would be identical and both would in theory plate out an identical amount of metal if there are no side reactions.

You could measure the metal recovered and record the voltage across each cell and temperature in the bath with a pretty simple system to try and quantify the change in efficiency. 

You could have one cell cooled with the slow water flow and one cell slightly warmed with a fish tank heater set to a little over what the self heating generates. This would give you 3 data points and some confidence that you are getting credible results.

The next time you do a run with changes in concentration of the electrolyte and you can even try some additives in your ABC test system.


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## Chris626 (Aug 22, 2022)

KalleMP said:


> To keep things scientific I would make the test with two as close to identical cells as possible and connect them electrically in series. The Coulombs of charge flowing through each cell would be identical and both would in theory plate out an identical amount of metal if there are no side reactions.
> 
> You could measure the metal recovered and record the voltage across each cell and temperature in the bath with a pretty simple system to try and quantify the change in efficiency.
> 
> ...


 
I’m not a DC guy, but I think you would want to connect the 2 bowls in parallel (Both bowls negative and both anode baskets positive), not connected in series. You might even want 2 separate power supplies so you could observe any differences in amperage draws between the 2 cells.


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## 4metals (Aug 22, 2022)

Interesting, yes in the pursuit of true science running the cells as identical as possible would be best. That is why I suggested identical anode material of the same dimensions and making the entire batch of electrolyte as one batch and using half in each cell. 

The electrical suggestion is also interesting because of this comment. 


Chris626 said:


> I’m not a DC guy, but I think you would want to connect the 2 bowls in parallel (Both bowls negative and both anode baskets positive), not connected in series.


You see, I'm not an electrical guy either, neither AC or DC, (not to be confused with being gender neutral I hope!) but I would appreciate someone with knowledge of the world of electric circuits to define the difference in these circuits as it pertains to running electrolytic cells. 

From my understanding, a parallel circuit *comprises branches so that the current divides and only part of it flows through any branch*. while a series circuit *comprises a path along which the whole current flows through each component*. In larger silver cells, with large rectifiers, I believe they are parallel circuits so the amperage remains the same but the voltage must be increased for each additional cell. 

Can an electrician confirm or deny this?


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## Chris626 (Aug 22, 2022)

4metals said:


> Interesting, yes in the pursuit of true science running the cells as identical as possible would be best. That is why I suggested identical anode material of the same dimensions and making the entire batch of electrolyte as one batch and using half in each cell.
> 
> The electrical suggestion is also interesting because of this comment.
> 
> ...





4metals said:


> Interesting, yes in the pursuit of true science running the cells as identical as possible would be best. That is why I suggested identical anode material of the same dimensions and making the entire batch of electrolyte as one batch and using half in each cell.
> 
> The electrical suggestion is also interesting because of this comment.
> 
> ...


Unfortunately I am an electrician but I can only accurately comment on AC circuits at 120/240v (USA residential) which is all I have professional experience with, but I can try I guess. 

I think running the 2 cells in series would be incorrect. That would be positive to the 1st anode, then connect the bowl of the 1st cell to the anode of the second cell and then the bowl of the second cell to the negative. 

The consensus seems to be to set the voltage constant on the power supply. ( I have read a few that say to set the amperage constant). Either way I don’t think it matters as far as a comparison experiment. I think if the cells are wired in series they will act as one cell electrically and if they’re in parellel they will act as 2 different branches (like you said. The voltage should be constant in my opinion and each cell will pull whatever amps it wants. In theory if all things are equal with the cells they should draw identical amperage. The question is whether temperature will effect the amp draw. That’s why I recommend 2 power supplies or at the very least you could use 1 power supply and meter each cell separately, but 2 power supplies would supply your separate meters. 

I think ultimately the cells would work either way in series or in parallel, but to compare how the 2 cells behave I would think either have 2 power supplies or have 1 with voltage set to a constant value and then have a meter on each branch to monitor the individual current draws.


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## Shark (Aug 22, 2022)

Years ago we ran a system they was 36 volt dc. It used one converter to take a 110ac circuit to 36volt dc. From that converter we ran a whole new line to as many as 48dc units. Each pluged into their own plug. One of our main problems was keeping positive and negative plugged right. This was pre one way plugs. The unit used was from electronic door locks and had very little amps drawn. If one got plugged in with the wrong positive/negative order every unit in line that was right would shock you if touching two units at the same time. If all were plugged correctly no problem. 36 volts at 1 amp won’t hurt you but it can make you hurt yourself.


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## olawlor (Aug 23, 2022)

For two electrolytic cells connected in series, each electron coming from the power supply goes through both cells, so the cells will see the exact same total amp-hours and hence (ignoring losses) the same mass of metal deposited. The power supply will need to supply about twice the normal voltage, but most electrolytic cells are run constant-current, so you let the voltage do whatever it wants depending on cell resistance.

For two cells in parallel, they see the same voltage, which would be correct only if you were running in constant voltage mode. Constant voltage is trickier to calibrate for metal production because the electrolyte solution resistance changes with distance, temperature, concentration changes due to evaporation, etc.


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## 4metals (Aug 23, 2022)

Then the amperage will remain constant and apply to all of the cells equally. If you run one cell at 1 amp at X volts to get that 1 amp, will adding a second cell in series (also drawing 1 amp) cause the voltage to double or is it necessary to ramp up the voltage to maintain the 1 amp.


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## 4metals (Aug 23, 2022)

On larger multi cell systems it is only possible to control the voltage.


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## Chris626 (Aug 24, 2022)

Is that because the voltage would get too high? 

I understand that the amount of crystal growth is dependent on the amperage. I’ve also read that if the voltage gets too high you’ll start to get other metals other then silver plating out. Isn’t that the best argument to always keep the voltage constant?

My experience is with AC. If you have a 60W bulb, at 120v it will draw .5 amps. At 60v it will draw 1 amp. 12v = 5amps. Ohms power law is true for AC and DC. 

My silver cell right now is drawing around 10w. 3.5v at 2.8 amps. I have voltage set to 3.5v and the amps do what they like. It’s been drawing 9-11W for the last 8 days. Am I correct to assume I have a 10w cell depending on it’s current conditions? (It’s resistance determined by many factors) If i set the voltage to 10v would it draw 1 amp? 20v = .5 amps? Am I missing something? I’m not going to try it, I’m very near to harvesting.


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## delboy9891 (Aug 25, 2022)

Very interesting, I usually go with constant voltage at 3.5 volts and let the amps do their own thing, I plan on using two separate power supplys for my experiment and as 4 metals suggested exact anode materials and electrolyte concentration, after I have done this experiment I might try constant amperage with the same hot and cooled cathodes and see what happens, irs trial and error at this point, just looking for the most efficient way of running my two small silver cells before I try a bigger silver cell, I have an 11 litre stainless steel stockpot that I would like to try for my next cathode


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## KalleMP (Aug 30, 2022)

To confirm.

With cells in series each would pass the same current and the voltage would fluctuate depending on cell conditions. The charge (current x duration) that passes each cell has to be identical so the yield will tell you what the relative efficiency of the two set-ups would be. You would have to have double the voltage compliance available to do this test so with nominally 3.5V cells you would have to have at least 7.0V available when using it at constant current. A real world problem can arise if the cells are sufficiently different that they have widely different cell voltages and their self heating, side reactions or gassing causes them to behave in ways that makes comparison unreliable. You would want to monitor and preferably log both cell voltages to learn something.

With cells in parallel the voltage in both cells would be constant and the the current would fluctuate depending on the cell characteristics. To learn something you would want to monitor and preferably log the cell currents, this is just a little less convenient than monitoring voltage but not that hard with modern gear. If you have a peak voltage in mind that you know will prevent undesirable reactions then this method will prevent such but the cells will run at different currents depending on their characteristics. You will have to integrate the current over time to determine what the theoretical yield will be for each of the cells, it would be based on the charge that has passed through the cell, this will be impossible to know without an accurate log of each cell current for the full duration. I do not advise this method for research but it is fine for production when you know what voltage works for you. You would need to have at least twice the current available at your chosen voltage.

As mentioned by #Chris626 the use of two power supplies is a good option, there are many DUAL output supplies on the market at reasonable prices. To compare yield you would have them in constant current mode. You need to trust the calibration (or check it) between the power supplies/outputs to make sure that they are running at equal currents or your yield calculations will be off. This will give the same results (if you trust the calibration) as a series connected test with additional over voltage safeguards independently for each cell.

This is not intended for production where parallel connection is usually the most convenient.

Placing two cells in series and simply measuring the voltages a few times will tell you which configuration is the more efficient as it will have the lower voltage. If you run to completion and check the metal yield you can make sure.

Just think Charge, or Coulombs, or electrons passing though and how many of them result in an atom of the desired metal plating out.


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## Yggdrasil (Aug 30, 2022)

There was an interesting post here regarding cells run in professional systems.








Designing a DIY silver cell


Metal gears would be best for long term use, I would think.




goldrefiningforum.com


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