Battery Fault

[WotEver]

8 hours ago, Dr Bob said:

Is this 12.5-33% of the Peuket losses or is it the % of the total charge?

Of the Peukert losses. 

[WotEver]

8 hours ago, nicknorman said:

But you haven’t explained how charge is lost, except by your amazing suggestion that charge is dropped due to passing through the battery’s resistance. Power is lost, voltage is lost. But charge isn’t lost - Kirchov’s first law.

What absolute bunkum!

It has nothing to do with Kirchhoff.

A battery is an energy containing device. It is charged up to hold x number of Wh. You could also express that in joules as Watt.Seconds.  A charge in Ah is an analogue of energy at a fixed voltage. 

You agree that power is lost yet you keep maintaining that the wasted power has no effect on the charge. Where do you suppose it came from, faries?

If you use power, whether by heating the battery or by powering an external device, the battery now contains less energy. Hence less charge in Ah. 

You would have us believe that a battery contains a charge and a separate inexhaustible supply of energy. It doesn’t. 

9 hours ago, nicknorman said:

No, because the battery doesn’t heat up due to lost charge, the battery heats up due to pushing current through finite resistance, simply   I^2R. No current /electrons are “dropped” when passing through a resistor.

Wrong. 

The battery heats up due to wasted power. Charge is an analogue of power. Heating the battery loses energy = reduced charge. 

[WotEver]

9 hours ago, Dr Bob said:

The fact internal resistance goes up means heat will be generated and surely there are some papers on how much that is.

I would assume there are somewhere but finding any has proved elusive for me. 

Even the battery university acknowledges that the rising internal resistance forms part of the Peukert losses but Nick simply dismisses that as they’re wrong too!

[WotEver]

Nick - a clue for you. What happens to the battery voltage under a heavy load?

[Dr Bob]

11 hours ago, Chewbacka said:

As I added to my post above, Electrons do drift and that is the basis of current flow - http://www.schoolphysics.co.uk/age16-19/Electricity and magnetism/Current electricity/text/Free_electron_motion/index.html

Energy states of atoms - electrons moving up and down orbit levels is not the same as current flow.  Voltage can cause electrons to drift and recombine with 'holes' and emit photons  - hence LED lights, or just drift about and manifest as current flow.

Ok, you are right. I accept defeat! So ...back to the chemistry....

[Dr Bob]

4 hours ago, WotEver said:

What absolute bunkum!

It has nothing to do with Kirchhoff. I've never met Kirchoff.

A battery is an energy containing device. It is charged up to hold x number of Wh. You could also express that in joules as Watt.Seconds.  A charge in Ah is an analogue of energy at a fixed voltage. I would agree with all of that.

You agree that power is lost yet you keep maintaining that the wasted power has no effect on the charge. Where do you suppose it came from, faries?

If you use power, whether by heating the battery or by powering an external device, the battery now contains less energy. Hence less charge in Ah. Yes that has to happen (see note below)

You would have us believe that a battery contains a charge and a separate inexhaustible supply of energy. It doesn’t. 

Wrong. 

The battery heats up due to wasted power. Charge is an analogue of power. Heating the battery loses energy = reduced charge. Correct.

In  the other post you estimate 12.5-30%  of Peuchets loss is truly lost so lets say 20%. The charge on the battery and the power remaining in the battery (ie amps, volts or whatever) will be the product of all the remaining reactive sites ie the concentration of Pb or PbO on the metal surface and the HSO4- ion concentration plus the charged electrons sitting post reaction waiting to go. If some of those reactants or charged electrons get used up by side reactions (causing gasing etc) or heating (via internal resistance) then they are not available for future reaction (on this discharge cycle) and are therefore lost to this cycle. This I think is the 20% that Wotever is talking about. I dont know whether Peuket used this in his theory. It seems sensible that some power/energy/reactants - call it what you like - will be lost as there is a charging efficiency problem on the reverse reaction so why not a discharge inefficiency on heavy discharge. I would go with 20%. As long as those side reactions do not take away reactants that are not converted back on the next cycle then that lost power will be available next time round. As far as I can tell the main permanent 'loss' is via sulphation which is not really relevant in this discussion.

The question for me is how many of the 10^23 molecules (or the electrons they produce) get caught up in these side reactions or battery heating.

Are you not both arguing the same thing with just the amount of these side reactions/heating the real issue?

[WotEver]

5 minutes ago, Dr Bob said:

Are you not both arguing the same thing with just the amount of these side reactions/heating the real issue?

Nick has never accepted that the losses from heating the battery result in lost charge. Pete neither but then he gets lost with talk of ‘missing electrons’. 

From an electrical standpoint the result of the rising internal resistance is a lower terminal voltage and hence less power per Ah. As the battery is an energy storage device more power is wasted internally during high discharges. 

I have absolutely no idea what happens chemically. I failed chemistry

[MtB]

Now the other day Wotever, Nick and DMR were ganging up on me and saying electrical stuff can be always explained with water analogies.

I'd be delighted if you lot could explain this debate about losses in Peukert in terms of buckets of water please 

[WotEver]

10 minutes ago, Dr Bob said:

I dont know whether Peuket used this in his theory.

Peukert used the most convenient tools he had to create an equation that fit with the observed phenomenon. I don’t believe he ever even attempted to say how the losses occurred. I know he never said how much was recoverable. 

1 minute ago, Mike the Boilerman said:

Now the other day Wotever, Nick and DMR were ganging up on me and saying electrical stuff can be always explained with water analogies.

I'd be delighted if you lot could explain this debate about losses in Peukert in terms of buckets of water please 

I absolutely did not. I said the total opposite. I believe my words were ‘water analogies never work well for electrical theory’.

[nicknorman]

4 hours ago, WotEver said:

What absolute bunkum!

It has nothing to do with Kirchhoff.

A battery is an energy containing device. It is charged up to hold x number of Wh. You could also express that in joules as Watt.Seconds.  A charge in Ah is an analogue of energy at a fixed voltage. 

You agree that power is lost yet you keep maintaining that the wasted power has no effect on the charge. Where do you suppose it came from, faries?

If you use power, whether by heating the battery or by powering an external device, the battery now contains less energy. Hence less charge in Ah. 

You would have us believe that a battery contains a charge and a separate inexhaustible supply of energy. It doesn’t. 

Wrong. 

The battery heats up due to wasted power. Charge is an analogue of power. Heating the battery loses energy = reduced charge. 

I think this perhaps hints at your confusion whilst tantalisingly suggesting that perhaps you do understand. Confusing!

It has to with Kirchhoff because current, which is the rate of change of charge, is preserved in a circuit. Current and hence charge cannot be "lost" through a resitive circuit generating heat.

A battery is an energy containing device. It has two primary parameters, charge (AH) and voltage. Charge has no intrinsic energy. It only has energy when the charge is raised to a potential (voltage). I think this might be where your confusion arises. We lazily talk about "charging" a battery. This is not just adding charge, this is adding charge at a potential. So we are adding energy, not just charge, to a battery when we charge it. However if you consider that a battery only contains charge and not also energy (by means of its voltage) one might get confused.

We know this really because when we talk about a "110AH battery" we know it doesn't describe the energy in the battery. It might be a 2v cell, a 6v battery, a 12v battery etc. But nevertheless people tend to associate charge with energy, mainly because most batteries are presumed to be 12v. However, the really important point is that something that measures charge, such as the AH indication on a battery monitor, is measuring just what it says on the tin - charge, in terms of AH. This has no concept of energy as it doesn't have any element of voltage. Exactly the same applies to Peukert, which only has charge and current and time in it, it has no voltage and so no energy. I'll repeat that, Peukert does not describe the loss of energy, only the loss of charge, which has no intrinsic energy.

Power is lost, because the current flowing out of the battery does so through some internal resistance and thus generates heat. At the output from the battery is the same current, the same rate of flow of charge and thus the same loss of charge after a specified period. What is lost is some of the voltage, so that the energy coming out is less, some of it is lost in the internal resistance. BUT this is not described by Peukert. Peukert only describes loss of charge, it does not describe loss of energy. These two effects - the temporary loss of charge, and the energy loss due to heat, are entirely different concepts. Peukert chose to describe the former. Which is fair enough, because that is fairly easy to describe. To know all the parameters that would be needed to describe the power loss wold be very complex.

[Dr Bob]

3 minutes ago, Mike the Boilerman said:

Now the other day Wotever, Nick and DMR were ganging up on me and saying electrical stuff can be always explained with water analogies.

I'd be delighted if you lot could explain this debate about losses in Peukert in terms of buckets of water please 

I dont think you can.

If you just look at the 'loss' of charge when you discharge at a very high rate compared to a low rate, that is down to the physical chemistry and a bucket of water wont cut it. What happens is that the majority of HSO4- ions near the surface of the PbO and Pb are used up in the discharge reaction leaving a lower concentration of HSO4- ions which then slows down the rate of the discharge reaction - hence it looks like charge is lost. If you rest the battery, the ions will migrate from the higher concentration away from the plates to the plates and therefore the rate of reaction can go back to what it was.  This is all nailed on, bog standard chemistry and not describable (is that a word?) from a bucket of anything. Maybe a bucket of beer would help getting to agreement.

[WotEver]

2 minutes ago, nicknorman said:

Peukert only describes loss of charge, it does not describe loss of energy

Oh Nick, for heaven’s sake!  If there is less energy stored within the battery then there is less charge available! Peukert noted this effect and created an equation which described it. He didn’t say ‘how’ he simply said “If you apply my equation you will see what is lost”

The charge is simply an analogue of the stored energy. Reduce the energy and you reduce the charge. Peukert made up an equation that shows the result, that’s all he did. 

[nicknorman]

8 minutes ago, WotEver said:

Nick has never accepted that the losses from heating the battery result in lost charge. Pete neither but then he gets lost with talk of ‘missing electrons’. 

From an electrical standpoint the result of the rising internal resistance is a lower terminal voltage and hence less power per Ah. As the battery is an energy storage device more power is wasted internally during high discharges. 

I have absolutely no idea what happens chemically. I failed chemistry

This is because losses from heating the battery cannot result in lost charge. Kirchoff's 1st law. But your problem is that you are lazily using the word "charge" to represent the energy of the battery. Charge is measured in coulombs or AH and in itself has no energy. Peukert describes loss of charge in AH/Coulombs, no concept of energy. By using the word "charge" to represent the energy of a battery you are causing the same confusion in yours and other's heads that arises when people say A/H or amps per hour when they mean A or AH. If you are going to engage in complex scientific topics, you really need to use the correct words with the correct dimensions to describe what you want to talk about.

Your second para is absolutely correct, but it is not described by Peukert and therefore it just causes confusion in your's and other's heads when you ascribe it to him.

[WotEver]

7 minutes ago, nicknorman said:

I think this might be where your confusion arises.

I’m not confused at all by what goes on. How you believe that the stored energy can be reduced without affecting the charge, that confuses me. Normally you’re quite an intelligent guy. 

[nicknorman]

1 minute ago, WotEver said:

Oh Nick, for heaven’s sake!  If there is less energy stored within the battery then there is less charge available! Peukert noted this effect and created an equation which described it. He didn’t say ‘how’ he simply said “If you apply my equation you will see what is lost”

The charge is simply an analogue of the stored energy. Reduce the energy and you reduce the charge. Peukert made up an equation that shows the result, that’s all he did. 

No, he didn't. He described loss of charge, not loss of energy. This is your blind spot.

[WotEver]

1 minute ago, nicknorman said:

Peukert describes loss of charge in AH/Coulombs

For no other reason than it was what he observed. Not because that’s the only thing going on. 

[nicknorman]

1 minute ago, WotEver said:

I’m not confused at all by what goes on. How you believe that the stored energy can be reduced without affecting the charge, that confuses me. Normally you’re quite an intelligent guy. 

Because energy = charge x voltage. If the voltage is reduced, the energy is reduced for the same charge.

[WotEver]

Just now, nicknorman said:

No, he didn't. He described loss of charge, not loss of energy. This is your blind spot.

He observed a loss of charge, not described it. That’s your blind spot. 

[nicknorman]

Just now, WotEver said:

For no other reason than it was what he observed. Not because that’s the only thing going on. 

But that is all his equation describes. Unless there was another bit written in invisible ink?

As I said, there is other stuff going on (energy losses due to resistance) but he didn't try to describe that in his equation, only the loss of AH. Which of course is temporary, whilst the loss of energy due to resistance is of course permanent.

1 minute ago, WotEver said:

He observed a loss of charge, not described it. That’s your blind spot. 

He observed it, then described it (or quantified it if you like) in his equation. The equation contains only AH, current and time. It is not possible for that to descibe anything to do with energy.

[WotEver]

Just now, nicknorman said:

As I said, there is other stuff going on (energy losses due to resistance) but he didn't try to describe that in his equation, only the loss of AH. Which of course is temporary, whilst the loss of energy due to resistance is of course permanent.

But that is just so completely wrong. He observed a lack of charge. That reduction is due to a loss of energy through heating the battery (and other stuff like bubbles) and due to slow dispersion. Peukert never tried to differentiate between the two causes, he simply created an equation which showed the cumulative loss of charge. 

[nicknorman]

3 minutes ago, WotEver said:

For no other reason than it was what he observed. Not because that’s the only thing going on. 

True, but he only wrote what he wrote. He probably did realise that other stuff was going on but his equation doesn't make any attempt to analyse or quantify it and thus to describe such losses as "Peukerts" is wrong and very confusing. Which is why you are very confused!

Just now, WotEver said:

But that is just so completely wrong. He observed a lack of charge. That reduction is due to a loss of energy through heating the battery (and other stuff like bubbles) and due to slow dispersion. Peukert never tried to differentiate between the two causes, he simply created an equation which showed the cumulative loss of charge. 

No, that reduction (lack of charge) is absolutely not due to a loss of energy through heating. Because such losses cannot "drop" current or charge. We are going round in circles here and you lack the basic comprehension of the difference between current/charge, voltage and energy.

[WotEver]

1 minute ago, nicknorman said:

True, but he only wrote what he wrote. He probably did realise that other stuff was going on but his equation doesn't make any attempt to analyse or quantify it and thus to describe such losses as "Peukerts" is wrong and very confusing. Which is why you are very confused!

But I’m not even slightly confused. You have some mysterious faries supplying power to heat the battery when Peukert has already shown the cumulative loss due to wasted energy in addition to slow dispersal. 

[nicknorman]

Its pointless carrying on a debate with someone who lacks a basic mathmatical and dimensional ability. I'm out.

 

Now, what was that battery fault again???

Edited November 29, 2017 by nicknorman

[WotEver]

Just now, nicknorman said:

Its point less carrying on a debate with someone who lacks a basic mathmatical and dimensional ability. I'm out.

It’s pointless trying to get someone to see past the end of their nose too. 

8 minutes ago, nicknorman said:

The equation contains only AH, current and time. It is not possible for that to descibe anything to do with energy.

So if there is less energy, in the new Physics Invented By Nick there is still the same charge?

Climb off your horse Nick and admit you’re wrong. 

[nicknorman]

We have a young chap in the gliding club, he did a degree in aeronautical engineering and is doing a PhD in computational fluid dynamics. He is pretty clever and a good pilot, and a nice guy. BUT he is a creationist. He firmly believes that the world started up a few thousand years ago, created by god in 7 days etc. He knows he is out of kilter with the rest of us but there is no swaying him. He just knows that he is right and any attempt at debate (and we have tried plenty!) is just met with blind faith that he is right regardless of any evidence. He actually seems to relish the challenge of having his views rubbished!

Now who does that remind me of???