The Peukert myth exposed

[nicknorman]

On the other hand, fascinating that a multitude of fossilised lurkers have suddenly sprung to life! Must be something in the water at this time of year.

Edited November 9, 2023 by nicknorman

[carlt]

2 hours ago, nicknorman said:

On the other hand, fascinating that a multitude of fossilised lurkers have suddenly sprung to life! Must be something in the water at this time of year.

My email inbox was suddenly full of CWF notifications of new posts by Gibbo and Chris W after years of dormancy so I found myself sucked back into the mire.

 

 

 

 

 

 

 

 

[DandV]

4 hours ago, nicknorman said:

On the other hand, fascinating that a multitude of fossilised lurkers have suddenly sprung to life! Must be something in the water at this time of year.

Your time will come!

[Gibbo]

14 hours ago, dmr said:

So are there two levels of Peukert?

1 A genuine loss of amp-hour capacity due to rapid discharge

2 A ficticious loss of capacity due to the on-load volt drop when discharging down to 10.5volt.

 

 

 

Basically, yes. Well, very close. Remove "amp-hour" and it's probably the most concise summary so far.

9 hours ago, nicknorman said:

Anyway, I think I may have killed Gibbo, which is a shame.

 

LOL No such luck I'm afraid. My central heating broke. Not the best time of year for it. I had to deal with that.

 

I think the Peukert argument has been done to death now, so...

 

You meantioned 3D printers. I actually got one last year. Printed a Benchy, then a bigger one. I've not used it since. Most useless device I've had for a long time. Care to argue about that?

[rusty69]

9 minutes ago, Gibbo said:

 

Basically, yes. Well, very close. Remove "amp-hour" and it's probably the most concise summary so far.

 

LOL No such luck I'm afraid. My central heating broke. Not the best time of year for it. I had to deal with that.

 

I think the Peukert argument has been done to death now, so...

 

You meantioned 3D printers. I actually got one last year. Printed a Benchy, then a bigger one. I've not used it since. Most useless device I've had for a long time. Care to argue about that?

With all due respect to you sir Gibbo, how can he possibly argue about that without knowing what other useless devices you own. 

[Gibbo]

3 minutes ago, rusty69 said:

With all due respect to you sir Gibbo, how can he possibly argue about that without knowing what other useless devices you own. 

 

You don't know Nick very well if you think he can't argue about that

[nicknorman]

2 hours ago, Gibbo said:

 

You meantioned 3D printers. I actually got one last year. Printed a Benchy, then a bigger one. I've not used it since. Most useless device I've had for a long time. Care to argue about that?

 

Like anything else, a 3D printer is only useful if you have a use for it. I've been doing a lot of hobby electronics recently (started during lockdown) as it is something to keep my 67 year old brain from freezing up. Used (free) RS DesignSpark PCB for the schematic and pcb layout. Learnt to programme in C using Microchip's (free) MPLAB X IDE (my projects tend to use PIC microcontrollers).

 

And the most astonishing thing is that a double sided pcb up to 100mm x 100mm with as many plated through holes as you like, silkscreen and solder mask on both sides, board outline whatever you like, really top quality with minimum track width and minimum track spacing of 0.005" can be obtained from China for   ... ... £3.47 for 5 boards including shipping. Yes that is not a misprint, three pounds and fourty seven pence for five boards including shipping to UK. Less than the price of a pint these days.  Or if you want 4 layer boards it is a hefty £11.30. I have never had a duff board.

 

One of my recent projects involved a 3D accelerometer chip that I browsed from the RS website, quite cheap at a couple of quid. But I hadn't quite noticed on the spec that the 10 pad device was 2mm x 2mm with pad width 0.2mm and pad spacing 0.2mm. That is never going to work!!! But it did, at first attempt to solder it on.

 

So having populated the board with mostly SM devices using solder paste and a hot air rework gun - £35 from ebay - I now need something to house it in.

 

Bring out the 3D printer. But first, design it with (free) Fusion 360 cad programme. That in itself takes a month to work out how to use even vaguely! Then slice with (free) Cura and then pop sd card into 3D printer Ender 3 (£200) and wait for it to print.

 

Here's one I prepared earlier, the angular position sensor using 2D magnetic flux sensor and diametrically magnetised spindle.

 

Still awaiting the pcb to come back from china but it is 25mm diamter and pops in between the two halves of the casing . The actual chip is shown there in its packaging awaiting soldering onto the pcb.

 

So is it useful? For me, yes.

 

 

[carlt]

2 hours ago, Gibbo said:

 

 

You meantioned 3D printers. I actually got one last year. Printed a Benchy, then a bigger one. 

Can you print me a 70' x 6'10" one please?

[Machpoint005]

It would be much easier for Nick to start whittling.

 

Or learn something really useful, like the clarinet.

 

[MtB]

2 hours ago, Gibbo said:

You meantioned 3D printers. I actually got one last year. Printed a Benchy, then a bigger one. I've not used it since. Most useless device I've had for a long time.

 

I quite fancy a 3D printer. Could you print me one please? 

 

Much obliged. 

[carlt]

14 minutes ago, Machpoint005 said:

It would be much easier for Nick to start whittling.

 

Or learn something really useful, like the clarinet.

 

A clarinet would be too complicated but I whittled myself a bamboo flute once, like the one Kwai Chang Caine from "Kung Fu" carried around on his back.

 

 

I couldn't get a note out of it but I didn't know if that was a result of my poor whittling skills or my lack of prowess as a flautist.

 

Perhaps a 3D printed one would be an improvement...

 

 

[nb Innisfree]

2 hours ago, carlt said:

A clarinet would be too complicated but I whittled myself a bamboo flute once, like the one Kwai Chang Caine from "Kung Fu" carried around on his back.

 

 

I couldn't get a note out of it but I didn't know if that was a result of my poor whittling skills or my lack of prowess as a flautist.

 

Perhaps a 3D printed one would be an improvement...

 

 

When they were filming the spear dodging intro in the TV series Kung Fu a spear accidently pierced the cheeks of actor David Carradine and pinned him to the backboard, his response to that was "what kung fu that!?" 

[Gibbo]

Long story but I got dragged back in by a private message. So... two points to make.

 

65watt hours gone.

 

65 watthours gone.

 

I know they're the same, but someone here seems to have no problem counting things twice.

 

And I'm gone again.

 

Nick, you are wrong. Tara.

[MIKE P]

On 09/11/2023 at 16:41, bizzard said:

I had a battery hen called ''Ever Ready'.

not oven ready