Battery Fault

[MtB]

39 minutes ago, nicknorman said:

I suspect it boils down to you using “charge” to mean the energy in the battery when in fact it means ... the charge! Charge is the property of something that causes it to feel a force when in an electric field. AH, coulombs or whatever. The integral of current. The Charge of a battery is on the label, 110AH or whatever. Charge is measured in an AH-counting SoC gauge. Charge, or the temporary loss of it, is what Peukert describes. Charge does not have the dimensions of energy any more than oranges do. 

If you use the wrong term it will always cause confusion. Just as if you said voltage when you meant current, charge when you meant oranges.

If I don’t pick folk up on it each time, a completely false and misleading impression is given.

 

I struggle to grasp the concept of charge, but when you described it as the integral of current it suddenly made sense. Thank you. 

 

 

[nicknorman]

16 minutes ago, Mike the Boilerman said:

 

I struggle to grasp the concept of charge, but when you described it as the integral of current it suddenly made sense. Thank you. 

 

Jolly good! I’m just amazed that anyone is still reading!

[smileypete]

Interesting paper.

Even so it shows the charge return difference as less than 5% between discharging at C/13 and a very high rate of C/1.3 followed by C/13. So nothing to do with Peukert...

However in the latter case the higher resting voltage at the end of the test does shows the charge is still there. The authors explain the difference as being due to the high discharge affecting the interface between grid and active material, presumably raising the internal resistance a little. And nothing to do with 'lost charge', Oh dear.

Still credit to Tony for finding something that very largely disproves his ideas.

On 11/30/2017 at 10:24, Dr Bob said:

Phew! Glad that's finshed..........what was the answer?

Peukert has no relevance whatsoever for 99.5% of boaters.

Edited December 1, 2017 by smileypete

[nicknorman]

30 minutes ago, smileypete said:

Still credit to Tony for finding something that very largely disproves his ideas.

So Harsh!

 

But fair!

[Sea Dog]

1 hour ago, smileypete said:

Peukert has no relevance whatsoever for 99.5% of boaters.

Really gotta feel for those poor 0.5 percenters though, eh?

[nicknorman]

7 minutes ago, Sea Dog said:

Really gotta feel for those poor 0.5 percenters though, eh?

Yeabut they are just the ones who THINK it’s relevant to them!

[Billy Boy]

So what was the answer to the question ( why was the red light on )

[WotEver]

1 minute ago, Billy Boy said:

So what was the answer to the question ( why was the red light on )

Faulty alternator

[cereal tiller]

52 minutes ago, Sea Dog said:

Really gotta feel for those poor 0.5 percenters though, eh?

I am 0.5 % and so is my Wife.our Offspring is named Peukert.

[rusty69]

3 minutes ago, cereal tiller said:

our Offspring is named Peukert.

Hooke would be better if he is the captain of your ship

[cereal tiller]

5 minutes ago, rusty69 said:

Hooke would be better if he is the captain of your ship

You are so Nauty Cal with your Verminology ,Oh ,hang on....

[rusty69]

3 minutes ago, cereal tiller said:

You are so Nauty Cal with your Verminology ,Oh ,hang on....

Is that the study of rats? 

[cereal tiller]

7 minutes ago, rusty69 said:

Is that the study of rats? 

 

Edited December 1, 2017 by cereal tiller

[smileypete]

14 hours ago, Sea Dog said:

Really gotta feel for those poor 0.5 percenters though, eh?

Only those with healthy batts who nevertheless who need to run a constant high load taking the voltage down to 10.5V.

0.5% is an exceedingly generous estimate, in practice it's probably more like a rounding error.

Contrast with the 95% who probably don't fully understand how to properly charge their batts, but most get by OK somehow.

Edited December 2, 2017 by smileypete

[WotEver]

On 25/11/2017 at 18:10, nicknorman said:

You have never answered the fundamental question about what happens to the chemicals. They react, you get a fixed number of electrons regardless of their temperature. Or they don't react, no electrons. But the chemicals are thus still available. The only thing that changes is how readily / quickly they react, especially the chemicals buried deeper in the plates. By your theory the chemicals have somehow reacted without giving as many electrons. That is impossible according to physics and chemistry as we know them.

 

Its all very well saying I am wrong but unless you come up with an alternative theory to explain your version of events, people aren't going to believe you any more than I believe our local vicar when he talks about god.

Pore Clogging is one phrase for it. Pore Blocking is another. A Google for either should demonstrate the error of your ways

Happy New Year

[Dr Bob]

1 hour ago, WotEver said:

Pore Clogging is one phrase for it. Pore Blocking is another. A Google for either should demonstrate the error of your ways

Happy New Year

Poor timing is another important issue.

[nicknorman]

1 hour ago, WotEver said:

Pore Clogging is one phrase for it. Pore Blocking is another. A Google for either should demonstrate the error of your ways

Happy New Year

I can find nothing to indicate that pore blocking causes permanent loss of available charge if a battery is discharged fast for a while, then very slowly, vs if a battery is discharged slowly all the way. So I don’t see your point.

7 minutes ago, Dr Bob said:

Poor timing is another important issue.

Especially when it’s taken him 6 weeks to come up with a non-point!

[WotEver]

9 minutes ago, nicknorman said:

I can find nothing to indicate that pore blocking causes permanent loss of available charge if a battery is discharged fast for a while, then very slowly, vs if a battery is discharged slowly all the way.

Then you’re not looking closely enough. 

Faster discharging causes faster pore blocking. Once a pore is blocked it remains blocked for that discharge cycle. None of your waiting around is going to recover the blocked pores. The sulphate won’t dissolve. Only a charge voltage will convert it.

That energy is lost for that cycle. Therefore the effective charge is lost on that cycle. 

As I’ve pointed out on numerous occasions, Peukert simply used some convenient numbers to describe what he saw, which (I would have thought, pretty obviously) includes ALL losses, not simply losses due to slow dispersion. 

Pore clogging is actually the biggest contributor to Peukert’s effect, not slow mobility. There are two other major effects and two lesser ones that together create the effect that Peukert noted. 

26 minutes ago, Dr Bob said:

Poor timing is another important issue.

Firstly, I thought it simpler to pick up in this thread rather than start another. Secondly, I have a life and a wife who’s been undergoing some pretty brutal cancer treatment over the last three months so I’ve not had much time to look at this issue. 

[nicknorman]

14 minutes ago, WotEver said:

Then you’re not looking closely enough. 

Faster discharging causes faster pore blocking. Once a pore is blocked it remains blocked for that discharge cycle. None of your waiting around is going to recover the blocked pores. The sulphate won’t dissolve. Only a charge voltage will convert it.

That energy is lost for that cycle. Therefore the effective charge is lost on that cycle. 

As I’ve pointed out on numerous occasions, Peukert simply used some convenient numbers to describe what he saw, which (I would have thought, pretty obviously) includes ALL losses, not simply losses due to slow dispersion. 

Pore clogging is actually the biggest contributor to Peukert’s effect, not slow mobility. There are two other major effects and two lesser ones that together create the effect that Peukert noted. 

Firstly, I thought it simpler to pick up in this thread rather than start another. Secondly, I have a life and a wife who’s been undergoing some pretty brutal cancer treatment over the last three months so I’ve not had much time to look at this issue. 

Firstly no-one is disputing what mr P observed and described. But you are not thinking properly about what he did observe and describe. He described loss of capacity. The crucial point is to understand what he meant by “capacity”

I've spent some time looking for any evidence that pore blocking is related to discharge rate, I haven’t found any so if you have some evidence, please provide a link to it.

your comment about pore blocking being the biggest contributor is clearly wrong by you own evidence (the students who discharged a battery fast, then let it rest and recovered most of the “lost” charge described by Mr P.)

 

Edited January 9, 2018 by nicknorman

[WotEver]

12 minutes ago, nicknorman said:

Firstly no-one is disputing what mr P observed and described. But you are not thinking properly about what he did observe and describe. He described loss of capacity. The crucial point is to understand what he meant by “capacity”

You have consistently argued that “no charge can be lost”, which it is, by pore blocking, and that “he only refers to charge because they’re the only units he uses” which is incorrect and probably explains why his equation is dimensionally incorrect. 

I have some stuff that I can send by email but no links at present. I’ll see what I can dig up. 

[bizzard]

Blocked pores leads to blackheads, regular scrubbing with a Loofah is the answer.

[WotEver]

23 minutes ago, nicknorman said:

your comment about pore blocking being the biggest contributor is clearly wrong...

A quick Google throws up...

Although at high rates, an exhaustion of sulfuric acid may occur in the positive plate as a result of acid transport limitation, the main factor that determines the EOD behavior is the change of the active surface area which is underpinned by the clogging of the pores...

From here:

http://ecst.ecsdl.org/content/25/35/223.short

[Dr Bob]

1 hour ago, WotEver said:

Firstly, I thought it simpler to pick up in this thread rather than start another. Secondly, I have a life and a wife who’s been undergoing some pretty brutal cancer treatment over the last three months so I’ve not had much time to look at this issue. 

I thought you would know my comments are usually very TIC . Truly sorry if I caused any offence. How all goes well at home.

[nicknorman]

1 hour ago, WotEver said:

A quick Google throws up...

 

 

From here:

http://ecst.ecsdl.org/content/25/35/223.short

No you are misreading it. It says that exhaustion of acid is the determining factor at high discharge rates (this is the peukert effect) but the comment about the loss of surface area is not in the part of the sentence talking about high discharge rates. Of course not all the reactive material is able to be reacted - the available plate area gradually reduces and quite probably doesn't tend to zero, but to a finite amount. However there is so far no evidence presented that shows that this amount varies according to the previous rate of discharge. As I said, the evidence you yourself presented showed that nearly all the "lost" charge could be recovered from a fast discharged battery, following a rest and a slow discharge. And IMO had the process been repeated probably all or nearly all the "lost" charge would have been recovered. So to say that the blocked pore effect (which is permanent until the next charge cycle) is responsibly for most of the charge "lost" according to Peukert, is clearly wrong.

As an aside, this effect does help me understand what happened to my cheapo leisure batteries that dropped to 50% capacity (lost 220AH) after 6 months leisure use and a proper charge regime. I found that an equalisation charge that just put in perhaps 20 AH (most of it lost to gassing) recovered the lost 220AH. Presumably I had a small quantity of some hard sulphate blocking a large proportion of the pores of the battery which was cleared by the equalise.

[MtB]

1 hour ago, WotEver said:

Secondly, I have a life and a wife who’s been undergoing some pretty brutal cancer treatment over the last three months so I’ve not had much time to look at this issue. 

 

I too would like to offer my best wishes to you both and wish your wife a good recovery, if that it possible.