How to recharge salt water battery

Thread Starter

Sulvek

Joined Aug 27, 2022
20
I have made 3 batteries.
1 Non iodized salt
2 White vinegar
3 Epsom salt

My question is how do I charge them?
I have lot's of tiny dixie cups so I can scale my voltages and I also have a bench power supply that can output 1-30V.
I have watched many videos but I'm not understanding how applying energy to the circuit is causing the electrons to flow back to the anode.
 

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LowQCab

Joined Nov 6, 2012
2,650
You can create your own "Lead-Acid-Cells" that must be charged to work.
All You need are 2 appropriately sized strips of Lead, and some thin Cardboard, ( thin-Poster-Board ),
roll the 3-strips into a spiral-shape,
it should be very tight, no loose-gaps anywhere,
put several Rubber-Bands around it to hold it's shape and tightness,
then put it in one of your Cups.

Soak the Cardboard in Salt-Water for around ~24-hours before winding the 3-Layers of the Cell.

Careful attention to the construction details is required for the best results.

They work best if You fill them with actual Battery-Acid from an Auto-Parts-Store,
( very dangerous stuff, be very careful ).

Salted-Water will also get the job done, ( after a lot of extra-work and massaging ),
and only after a much longer initial Charge,
and several full Charge/Discharge-Cycles.

The first Charging-Cycle may take several hours.

For Initial-Charging, limit the Current to about 0.5-Amps,
and let the Voltage go wherever it wants, ( but not more than around ~3-Volts ).
If the Electrolyte starts boiling excessively, and the Cell starts getting HOT,
back-off on the Current, because You will only be causing damage to the Cell.
You can't make it Charge faster than what it will safely tolerate.

The fully Charged-Cell-Voltage will be around 2 to 2.2-Volts.

Be careful of the Hydrogen and Chlorine gasses given-off during Charging.

If You NEVER let the Electrolyte get low,
and if You keep it on a "Maintenance-Charger",
it will easily last several years.
.
.
.
 

shortbus

Joined Sep 30, 2009
9,762
You can create your own "Lead-Acid-Cells" that must be charged to work.
All You need are 2 appropriately sized strips of Lead, and some thin Cardboard, ( thin-Poster-Board ),
roll the 3-strips into a spiral-shape,
Lead? you may have invented a new battery. Lead doesn't seem to be used in conventional salt water batteries.

;
;
;
;
 

Thread Starter

Sulvek

Joined Aug 27, 2022
20
You can create your own "Lead-Acid-Cells" that must be charged to work.
All You need are 2 appropriately sized strips of Lead, and some thin Cardboard, ( thin-Poster-Board ),
roll the 3-strips into a spiral-shape,
it should be very tight, no loose-gaps anywhere,
put several Rubber-Bands around it to hold it's shape and tightness,
then put it in one of your Cups.

Soak the Cardboard in Salt-Water for around ~24-hours before winding the 3-Layers of the Cell.

Careful attention to the construction details is required for the best results.

They work best if You fill them with actual Battery-Acid from an Auto-Parts-Store,
( very dangerous stuff, be very careful ).

Salted-Water will also get the job done, ( after a lot of extra-work and massaging ),
and only after a much longer initial Charge,
and several full Charge/Discharge-Cycles.

The first Charging-Cycle may take several hours.

For Initial-Charging, limit the Current to about 0.5-Amps,
and let the Voltage go wherever it wants, ( but not more than around ~3-Volts ).
If the Electrolyte starts boiling excessively, and the Cell starts getting HOT,
back-off on the Current, because You will only be causing damage to the Cell.
You can't make it Charge faster than what it will safely tolerate.

The fully Charged-Cell-Voltage will be around 2 to 2.2-Volts.

Be careful of the Hydrogen and Chlorine gasses given-off during Charging.

If You NEVER let the Electrolyte get low,
and if You keep it on a "Maintenance-Charger",
it will easily last several years.
.
.
.
Wow! Thanks a lot for that. Is there a name for this lead/salt battery? Or did you come up with it. Would love to see some finished examples.
 

shortbus

Joined Sep 30, 2009
9,762
Wow! Thanks a lot for that. Is there a name for this lead/salt battery? Or did you come up with it. Would love to see some finished examples.

Look for the words "salt water battery" on Google or any search engine. They don't use lead. They were developed to get away from the heavy metal (lead) problems and the dangerous acid problems.
 

LowQCab

Joined Nov 6, 2012
2,650
In a DIY Lead-Acid Battery,
(if You don't use Battery-Acid to start with),
the Salt only makes the Water conductive.

Pure-Water is a very good insulator,
and You need to have a Current-Flow in the Cell to generate your own Acid.

This is why the Cell won't provide any Voltage right away,
it takes much more initial Charging-Time to change the Water into Acid,
and to change the chemical properties on the surfaces of the 2 Lead-Plates.
The Lead will actually change into a different Compound with enough Charging-time.


With Salt-Water,
it will take quite a few Charge / Discharge Cycles before
the Cell will start retaining a Charge, and actually storing a useful amount of energy.
If You start with Battery-Acid, things start working much faster.
.
.
.
 

shortbus

Joined Sep 30, 2009
9,762
Pure-Water is a very good insulator,
and You need to have a Current-Flow in the Cell to generate your own Acid.
OK I'll bite. Give a link or some chemical simulation where water and sodium chloride, will change to sulfuric acid when electric current and lead sheets are involved. I'll even ask the forums chemist, @MrSalts to chime in on this. Not saying it's impossible just never heard of such a thing.
 

MrSalts

Joined Apr 2, 2020
2,622
OK I'll bite. Give a link or some chemical simulation where water and sodium chloride, will change to sulfuric acid when electric current and lead sheets are involved. I'll even ask the forums chemist, @MrSalts to chime in on this. Not saying it's impossible just never heard of such a thing.
Lead/Lead Chloride batteries are known and have been built using sea water or salt water. It is not as easy as just adding salt water to lead - as far as I know. I'd like to see some detail plans of the set up and give it a try.

Here is one patent to put the lead chloride on an nickel grid.
https://patents.google.com/patent/US4021597A/en
 

LowQCab

Joined Nov 6, 2012
2,650
The Cell I was speaking of was based on a project that everyone in
my 7th-Grade Science-Class was instructed to create. ( ~1970-ish ).
It was part of a "Kit" that was assigned to each student.

The clear-plastic-container came with a snap-on-lid with 2 holes in it
for the small-lead-strips that were attached to the ends of each layer of the Cell,
and was about ~2" in diameter, and ~3" tall.

It was not very "efficient", but then most, if not all,
DIY Batteries are usually pretty poor performers.

I had a pretty good idea of what was going on with the assignment, so,
not surprisingly, my Cell was the best performing in the Class.
The task was to power a small Electric-Motor that would
wind-up a string with a small weight attached to it,
from the floor, up to the edge of the Work-Table.
My Cell would perform the task ~4 to ~5 times before finally pooping-out,
and the performance got noticeably better with each Charge/Discharge-Cycle.
.
.
.
 

camerart

Joined Feb 25, 2013
3,292
I have made 3 batteries.
1 Non iodized salt
2 White vinegar
3 Epsom salt

My question is how do I charge them?
I have lot's of tiny dixie cups so I can scale my voltages and I also have a bench power supply that can output 1-30V.
I have watched many videos but I'm not understanding how applying energy to the circuit is causing the electrons to flow back to the anode.
Hi s,
Slightly different, but have you heard of sodium-iron batteries?
Camerart
 

MrSalts

Joined Apr 2, 2020
2,622
The Cell I was speaking of was based on a project that everyone in
my 7th-Grade Science-Class was instructed to create. ( ~1970-ish ).
It was part of a "Kit" that was assigned to each student.

The clear-plastic-container came with a snap-on-lid with 2 holes in it
for the small-lead-strips that were attached to the ends of each layer of the Cell,
and was about ~2" in diameter, and ~3" tall.

It was not very "efficient", but then most, if not all,
DIY Batteries are usually pretty poor performers.

I had a pretty good idea of what was going on with the assignment, so,
not surprisingly, my Cell was the best performing in the Class.
The task was to power a small Electric-Motor that would
wind-up a string with a small weight attached to it,
from the floor, up to the edge of the Work-Table.
My Cell would perform the task ~4 to ~5 times before finally pooping-out,
and the performance got noticeably better with each Charge/Discharge-Cycle.
.
.
.
Our memories of 7th grade and our base knowledge by 7th grade are both questionable.
It is most likely that your kit was some variation of the age-old "potato clock" where the potato is billed as the source of power but it is really just the electrolyte (salt bridge) for the two metal strips provided (typically, one copper and one zinc. Similar "batteries can be made by placing a nickel coin and a copper coin the ends of a small strip of paper wetted by saliva. You can measure a voltage. You can stack them in series and add the voltages.

In any case, I'm guessing that your kit contained two different metals and the salt water was simply the electrolyte. Common metals that a 7th grader may not differentiate, zinc or galvanized steel, soft iron, mild steel, lead, tin. Any different metal with a salt bridge will generate a voltage.

If the strips were just an inch or two each x 1/4 or 1/8", I doubt there was enough surface area to develop the current to power a motor. There may have been a coil of the strip or a part of the circuit that you are not remembering completely.
 

LowQCab

Joined Nov 6, 2012
2,650
It was definitely very-soft, very-thin, Lead,
I was not only quite sure of it by my experience in a unique specialty Machine-Shop,
the instructions that were provided also stated that both strips were Lead,
and that they would not be polarized until after Charging.

Admittedly, proper Battery-Acid would have been much faster, and more effective,
but Tap-Water got the job done well enough to complete the short demonstration.
.
.
.
 

shortbus

Joined Sep 30, 2009
9,762
In any case, I'm guessing that your kit contained two different metals and the salt water was simply the electrolyte. Common metals that a 7th grader may not differentiate, zinc or galvanized steel, soft iron, mild steel, lead, tin. Any different metal with a salt bridge will generate a voltage.
That is what I was getting at. While both plates in a lead/acid battery are lead one of them is a lead grid filled with lead sulfate(I think that's the chemical name). The lead sulfate is enough different that the acid sees it as s different metal.

But back to my original question. Will as LQ is claiming, salt water turn into sulfuric acid due to an electric current? I can see from my very basic chemical knowledge, and searching on line, where this is possible. H2O and NaCL contain no "magic" sulfur to make sulfuric acid.
 

MrSalts

Joined Apr 2, 2020
2,622
That is what I was getting at. While both plates in a lead/acid battery are lead one of them is a lead grid filled with lead sulfate(I think that's the chemical name). The lead sulfate is enough different that the acid sees it as s different metal.

But back to my original question. Will as LQ is claiming, salt water turn into sulfuric acid due to an electric current? I can see from my very basic chemical knowledge, and searching on line, where this is possible. H2O and NaCL contain no "magic" sulfur to make sulfuric acid.
No, sodium chloride cannot become lead sulfate. You'd need a source of sulfur to make lead sulfate. However, the sulfate could, in theory, be replaced by Hydrochloric acid (with the risk of oxidizing chloride ion to Chlorine gas AND hydrochloric acid dissipating as hydrogen chloride gas into the air over time because it can be volatile at higher concentrations). The sulfur atom (as sulfate ion) does not participate in the electrochemical reaction and could be replaced by Cl ion (as HCl(aq)). It is conceivable that a layer of lead chloride will develop on the surface of the electrode but some method must be used to precipitate out (or sequester) in a way I am not seeing.
 
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