Where's Gibbo? Split From: Robust debate Technical discussions.

[Murflynn]

where's Gibbo?

[nicknorman]

where's Gibbo?

Gibbo was right about some things. Well I'd go so far as to say most things. But he was wrong about some things. As I said, no-one has copyright on always being right. Yes, grudgingly, even me!

Edited February 12, 2016 by nicknorman

[Loafer]

Just stick to the forum format. If you want definitive knowledge go and buy some text books...(i'd rather have this forum anyday).

Knowledge changes, new people turn up here all the time asking the same old questions but they don't get the same answers each time because things and forum knowledge are evolving all the time. Sometimes there are different opinions and are both are correct. Wikipedia is great but it would be a huge effort to create something like this and keep it up to date.

And as Nick has said, we could have experts like Gibbo writing the electrical sections, but he did get some things wrong, and without debate and updating that wrong knowledge would be cast in stone.

 

...............Dave

 

 

Can you give me a frinstance of something that Gibbo got wrong? Wasn't his lottery numbers was it?

 

Honest question. He was just about 'before my time'!

[MtB]

 

 

Can you give me a frinstance of something that Gibbo got wrong? Wasn't his lottery numbers was it?

 

Honest question. He was just about 'before my time'!

 

 

He asserted that his off colour joke should stay on the forum, or he would leave.

 

In giving that ultimatum he left himself no way of climbing down without 'losing face'. That was an error of judgement in my opinion, otherwise known as 'getting it wrong'!

[Loafer]

 

 

He asserted that his off colour joke should stay on the forum, or he would leave.

 

In giving that ultimatum he left himself no way of climbing down without 'losing face'. That was an error of judgement in my opinion, otherwise known as 'getting it wrong'!

 

Ah see. Nothing electricle?

 

Edit: Can you PM me the joke?

Edited February 13, 2016 by Loafer

[MtB]

Not that I ever noticed...

[Loafer]

Not that I ever noticed...

 

See my edit - crossed posts! IE, can you PM me the joke?

[Paul C]

After having read and re-formatted about 60% of his technical articles, his English and writing skills are far from perfect!!! The technical details seem okay, although I might have just come across a mistake

[MtB]

 

See my edit - crossed posts! IE, can you PM me the joke?

 

 

Nope. I never saw it! The mods deleted it in a flash.

 

On reflection, I think his ultimatum to the mods was actually, "restore my joke or I'm never posting again". And the mods told him to shove it. Which naturally didn't go down too well with our Gibbo...

[WotEver]

Was it "What's the difference between jam and marmalade"?

 

Yup.

[smileypete]

Can you give me a frinstance of something that Gibbo got wrong? Wasn't his lottery numbers was it?

 

Honest question. He was just about 'before my time'!

 

That's easy; the whole Peukert thing for a start:

 

http://www.smartgauge.co.uk/peukert2.html

 

'Mr Peukert first devised a formula that showed numerically how discharging at higher rates actually removes more power (see below before thinking this is wrong) from the battery than a simple calculation would show it to do. For instance discharging at 10 amps does not remove twice as much power as discharging at 5 amps. It removes slightly more.'

 

Which is wrong Have to acknowledge that it was Nick Norman that pointed this out sometime after Gibbo left.

 

I think he was broadly right on most things but conveyed his knowledge with a lot of personal dogmatic bias, and his interpersonal skills were sometimes lacking (see above) though entertaining to some.

 

I remember despairing somewhat when he implied someone shouldn't discharge their newly acquired traction batts below 50%. And then when I later called him out on it...

 

http://www.canalworld.net/forums/index.php?showtopic=40238&p=736092

http://www.canalworld.net/forums/index.php?showtopic=51271&p=959924

Edited February 13, 2016 by smileypete

[WotEver]

 

That's easy; the whole Peukert thing for a start:

 

http://www.smartgauge.co.uk/peukert2.html

 

'Mr Peukert first devised a formula that showed numerically how discharging at higher rates actually removes more power (see below before thinking this is wrong) from the battery than a simple calculation would show it to do. For instance discharging at 10 amps does not remove twice as much power as discharging at 5 amps. It removes slightly more.'

 

Which is wrong

Pete, are you deliberately ignoring the paragraph that follows that statement?

Please note that there are two ways of looking at this effect. We could say that discharging at higher currents reduces the total available power that can be got out of a battery. So a 100 amp hour battery might become say an 80 amp hour battery at higher discharge rates. This is technically the correct way of looking at it

My bold (but Gibbo's words)

[nicknorman]

Pete, are you deliberately ignoring the paragraph that follows that statement?

But just look at Gibbo's quotes in your post. He is mixing power with energy with charge (AH). Now I know that you have a lot of respect for him, as do I, but he was not perfect and did make some mistakes, in this case the product of carelessness. What is important is to recognise those mistakes as mistakes (which we all make) and not to say that every word he spoke was perfect.

 

IMO, his take on Peukert was not the best. Quite a lot of it wasn't wrong, but it was a bit misleading in the context of boat electrics.

[dmr]

I feel I can criticise Gibbo because I learnt a lot from him. Also he was so cruel to people who argued with him, but did it with such style that I very nearly peed myself laughing a fair few times.

So....

1 He elevated the 50% rule from a general guidance to a religion without real justification.

2 He was obsessed by correctly wiring battery banks when it really don't matter that much.

3 He was irrationally opposed to external alternator controllers because he bizarrely marketed his Smartbank as a rival to these, and then he talked rubbish about inserting extra diodes into alternators.

 

This is a bit harsh but if he is reading this it might just temp him back which would be really good.

 

.................Dave

[MtB]

I suggest you edit out that last bit, if you want it to be really effective...

[dmr]

I suggest you edit out that last bit, if you want it to be really effective...

 

I have sometimes pondered whether he still reads this forum, and what outrageous post might temp him back, but I reckon he is the sort of person who once gone would go good and proper and move on.

A lot of the electrical knowledge on this forum is rather second hand and it was rather nice to get the first hand stuff.

 

.................Dave

[smileypete]

Pete, are you deliberately ignoring the paragraph that follows that statement?

 

My bold (but Gibbo's words)

 

LMAO.

 

This in yet another of Gibbos problems, he'd state something categorically, then state something almost contradictory. Anyone trying to properly understand the subject didn't have a cat's chance in hell of doing so. But if you pulled him up on something he'd be able to interpret it however he liked.

 

OK here's another page from his site:

 

http://www.smartgauge.co.uk/splitting.html

 

'Assume a single battery bank of 400 amp hours. With an average load on it of 30 amps. Let's say Peukert's exponent for these batteries is 1.3, the typical figure for deep cycle wet cells.

This gives a total run time, to 50% state of charge, of just under 6 hours (use the Peukert Calculator).'

 

Wrong! 200Ah/30A to 50% is 6.6 hours.

 

Put it this way, what SoC would you expect to see from resting voltage in Gibbos example?

 

The problem is that Peukert is effectively a myth when discharging to 50%.

 

If you could erase all Gibbos teachings on Peukert from your brain, and talk to an experienced batt engineer, you'd probably have a far better chance of understanding it properly.

 

Now all the average boater needs to 'get', is that most if not all batt capacity loss problems are due to inadequate charging, where the batts seldom if ever gets a proper full charge.

[WotEver]

IMO, his take on Peukert was not the best. Quite a lot of it wasn't wrong, but it was a bit misleading in the context of boat electrics.

Sure some of his writing was clumsy but he's trying to explain a possibly complex subject to a layman using the simplest possible terms.

 

To just blandly say "he was wrong" is incorrect, especially when he explains in the following paragraph that he's simply trying to explain a concept and the better description is that the capacity of the battery is reduced.

 

Anyway, it's not incorrect to say that the total power available had reduced - if the capacity is reduced so is the total power available.

 

Tony

[nicknorman]

Anyway, it's not incorrect to say that the total power available had reduced - if the capacity is reduced so is the total power available.

Tony

No, power is an instantaneous concept. If he had said the total energy available was reduced it would at least have been dimensionally correct, but still slightly misleading (because it depends on the timescale).

[WotEver]

If you could erase all Gibbos teachings on Peukert from your brain, and talk to an experienced batt engineer, you'd probably have a far better chance of understanding it properly.

I've read many papers on the subject from battery university to Wikipedia to battery manufacturer papers. And Gibbo's too. To my mind they all say much the same thing - the faster you discharge a battery the less capacity it will have. Mr Peukert said so.

 

Now all the average boater needs to 'get', is that most if not all batt capacity loss problems are due to inadequate charging, where the batts seldom if ever gets a proper full charge.

Completely agreed

 

Tony

[nicknorman]

I've read many papers on the subject from battery university to Wikipedia to battery manufacturer papers. And Gibbo's too. To my mind they all say much the same thing - the faster you discharge a battery the less capacity it will have. Mr Peukert said so.

Tony

This is a really important point. And trust me, I'm a pilot! But anyway the statement "the faster you discharge a battery the less capacity it will have" is true but misleading. True if you maintain that discharge rate until flat. But misleading because if you don't maintain that discharge rate until flat, but decrease it or pause it (as is typical for a boat) the "lost" capacity is recovered.

[WotEver]

This is a really important point. And trust me, I'm a pilot! But anyway the statement "the faster you discharge a battery the less capacity it will have" is true but misleading. True if you maintain that discharge rate until flat. But misleading because if you don't maintain that discharge rate until flat, but decrease it or pause it (as is typical for a boat) the "lost" capacity is recovered.

Yup, accepted.

[WotEver]

I have sometimes pondered whether he still reads this forum...

No he does not.

[smileypete]

Gibbo (seems to?!?) repeat his mistake later on in the above page too:

 

'If we now use the actual current draw of 5 amps for a third of the time we get a run time of 121 hours to totally flat, so this is 60.5 hours to 50% state of charge, but this is only for a third of the time so the true run time will be 3 times this = 181 hours. This is somehwat less than the calculated figure using the average current consumption. This is to be expected as a direct result of Peukert's effect (drawing 5 amps from a battery removes more power from the battery than drawing 1.67 amps for three times as long - this is what Peukert's effect is all about).'

 

It's interesting that the earliest versions of his Peukert page omit the sentence Tony highlighted, but other pages are pretty much the same.

 

All Peukert really does, is allow you to predict how long until you hit a safe minimum terminal voltage with a given constant load.

 

If you're discharging to around 50% you're very unlikely to hit this voltage unless drawing huge amounts of power (say between C/2 and C/1), or the batts are pretty knackered already. So I'd say that Peukert was largely irrelevant for 50% discharges - THE END!

Edited February 14, 2016 by smileypete

[nicknorman]

 

All Peukert really does, is allow you to predict how long until you hit a safe minimum terminal voltage with a given constant load.

 

If you're discharging to around 50% you're very unlikely to hit this voltage unless drawing huge amounts of power (say between C/2 and C/1), or the batts are pretty knackered already. So I'd say that Peukert was largely irrelevant for 50% discharges - THE END!

Yes absolutely and totally correct. As a matter of interest I changed Peukert's exponent to unity on our Mastershunt for a while. No impact on SoC etc. Probably an impact on time to run, but I never look at that.

 

Which at least shows that Mastervolt understand Peukert's impact on SoC!

Edited February 14, 2016 by nicknorman