Lead Acid Batteries

jssailem

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
22,775
CAL 35 Cruiser #21 moored EVERETT WA
We know all there is to know about these batteries... Yes... No... maybe?

While looking at the subject and refreshing my thinking, especially in light of all the interest in LiFePO4 batteries, I came across this compact review of Lead Acid batteries be them Flood, AGM, Gel etc.

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This guide was published on Panbo.com and produced by Luis Soltero.

panbo.com

A guide to understanding boat batteries part 1, lead-acid

Earlier this year, unfortunately, we roasted the 1,855 amp hour battery bank needed to achieve electrical nirvana on our 40-foot trawler Bliss. And that meant a painfully expensive and unbudgeted replacement, plus a period of no lights, no engine, and no electric toilet. So having recently...
panbo.com

I hope this helps you with your battery questions.
 
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JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
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Hunter 430 Waveland, MS
One other Chemical Fact...

The Earth continues to make new Lead [Pb] each day.

Jim...

PS: No new Lithium [Li] made on Earth each day.:(
 
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rgranger

rgranger

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Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
jssailem said:
View attachment 221786
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This diagram is VERY not correct. Actually I think it might be the diagram for the hydrolysis of water and has nothing to do with a battery. For example, in this diagram, water is consumed and converted into hydrogen and oxygen gas. The gas would leave and very soon your battery would run dry. In fact, the exact opposite reaction, (the conversion of 2H2 and O2 into 2H2O) is how a fuel cell opperates. In this scenario, your battery would constantly consume water and electricity would need to be added IN....

In a Pb-Acid battery H+ is produced at the anode but on the cathodic side of the cell it combines with the hydrogen sulfate anion to produce sulfuric acid. It does not pick up an electron and become a neutral hydrogen atom.

1701953442896.png
 
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American_Mainsail

American_Mainsail

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Dec 4, 2023
133
Hunter 44 Portsmouth
rgranger said:
This diagram is VERY not correct. Actually I think it might be the diagram for the hydrolysis of water and has nothing to do with a battery. For example, in this diagram, water is consumed and converted into hydrogen and oxygen gas. The gas would leave and very soon your battery would run dry. In fact, the exact opposite reaction, (the conversion of 2H2 and O2 into 2H2O) is how a fuel cell opperates. In this scenario, your battery would constantly consume water and electricity would need to be added IN....

In a Pb-Acid battery H+ is produced at the anode but on the cathodic side of the cell it combines with the hydrogen sulfate anion to produce sulfuric acid. It does not pick up an electron and become a neutral hydrogen atom.

View attachment 221801
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According to the source I'm looking at, How Boat Things Work: An Illustrated Guide (very cool book - recommend), the reaction they're showing is indeed hydrolysis; which occurs when the battery is charging and becomes overcharged. My understanding is that there's no PbSO4 left to react and make PbO2 on the positive electrode, so the reaction becomes straight up hydrolysis.

My source doesn't explicitly say this, but a quick Google search says that the hydrolysis reaction occurs a little bit as the battery tops off due to differences in charge of the individual cells (some cells are slightly overcharged while others are still charging).
 
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JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
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Hunter 430 Waveland, MS
American_Mainsail said:
the reaction they're showing is indeed hydrolysis; which occurs when the battery is overcharged.
Click to expand
This is the reason you need a Regulated Battery Charger.

That type Charger uses the Amperage as feed back to properly control it.

Most Chargers have a Balance Charge mode when 2 or more Lead/Acid [not AGM] are in parallel.

During that balance charge, the Batteries can make Hydrogen. :cool:

Safety First

Jim...
 
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JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,745
Hunter 430 Waveland, MS
rgranger said:
It does not pick up an electron and become a neutral hydrogen atom.
Click to expand
Using @rgranger Over Cell Balance of 2.041 Volts

When fully charged and connecting 6 plates together then...

2.041 X 6 = 12.246 VDC

The fully charged standard Volts on your Lead/Acid Battery :clap:

Jim...
 
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rgranger

rgranger

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Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
JamesG161 said:
This is the reason you need a Regulated Battery Charger.
Click to expand
Correct!:beer:

Were we talking about charging? Maybe I jumped the gun on my critique? I thought the diagram was showing the discharge of the battery. Anyway, the charging should be the reverse of the discharge reaction unless you over charge or charge too aggressively.
 
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BarryL

BarryL

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May 21, 2004
1,057
Jeanneau Sun Odyssey 409 Mt. Sinai, NY
Hello,

You need to add this statement to your first picture:

An unwanted (and unfortunate) side reaction occurs during the charging cycle. Passing a current through an electrolyte causes water to disassociate into hydrogen (H2) and oxygen (O2). This process is known as electrolysis and releases hydrogen at the battery’s negative pole and oxygen at the positive pole.

Without that statement your picture is very confusing.

Barry
 
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JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,745
Hunter 430 Waveland, MS
JamesG161 said:
One other Chemical Fact...

The Earth continues to make new Lead [Pb] each day.
Click to expand
Most Radioactive Elements end their Decay series with LEAD [Pb]


A few exceptions are the Radioactive Gases. Example is Argon [Ar], which ends its Decay series with no electron Helium [ He-4].

No new Lithium [Li] is made on Earth.

I will stick with my Boat's Lead/Acid batteries. :pimp:

Jim...
 
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JamesG161

JamesG161

SBO Weather and Forecasting Forum Jim & John
Feb 14, 2014
7,745
Hunter 430 Waveland, MS
BarryL said:
Without that statement your picture is very confusing.
Click to expand
That is why in my Post #2 above I added the picture, which was also taken from the same Article that @jssailem linked in his original post.

SBO's top Chemist is @rgranger so listen to him.

I am a Chemical Engineer, who makes his chemistry manufactured for our non laboratory size. :biggrin:

Jim...
 
rgranger

rgranger

.
Jan 19, 2010
12,553
Hobie 16 & Rhodes 22 Skeeter Charleston
JamesG161 said:
A few exceptions are the Radioactive Gases. Example is Argon [Ar], which ends its Decay series with no electron Helium [ He-4].
Click to expand
I don't think that is an accurate statement. There are 26 known isotopes of Argon but most are exceedingly rare. The only isotopes of appreciable concentration are Argon-36, Argon-38 and Argon-40 with Argon-40 making up the vast majority. Argon 36 and Argon 38 are made in the furnace of stars but 40 is the final decay product of radioactive potassium. BUT all three isotopes are stable. There are radio active isotopes of argon but most of those are someplace on a decay path and are VERY rare and none that I could find end in Helium.


When a particle containing two protons and two neutrons is ejected from a nucleus we call that an alpha particle and it does look like a "no electron" helium but ..it is very high energy and will capture electrons at some point and become a helium atom.

Here are some examples of Argon decay schemes.
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1701977350840.png
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SBO only allows 10 attachements but... I did not see any other Argon decay series ending with Helium.
 
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dLj

dLj

.
Mar 23, 2017
4,256
Belliure 41 Back in the Chesapeake
While the article was an interesting overview, what I've still never seen well explained is the sulfation process.

That would have gotten me much more interested in reading that in its entirety.

dj
 
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