Can anyone explain how this battery charger works?...

[Commander Kinsey]

On Mon, 14 Feb 2022 12:22:30 -0000, Paul <nospam@needed.invalid> wrote:

On 2/13/2022 5:33 PM, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:

On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ

Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?

Maybe it\'s an AC battery? They are very useful for grid storage applications as long as you can control the phase.

What makes you think that component is a capacitor? I\'m assuming you drew the schematic.

I\'ve learned from someone on Quora that it\'s actually a PTC Fuse - a resettable semiconductor fuse.

The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it\'s to stop a busted battery from being overcharged when a cell has died.

The shape of the edge of the device,
hints that it is not a disc capacitor.

One reason for that, is the material the yellow
thing is dipped in, is a hell of a lot harder,
than the softer stuff used on the older disc caps.
The yellow material might be intended to be
flame proof or the like.

As a connoisseur of circuits, I bet you\'ve already
made up your mind as to whether this circuit is a
good idea or a bad idea...

It\'s not going to be used anymore anyway. It was for NiCads (which are too old and tired), and I\'m changing the battery packs to LiIon, which I\'ll just charge form a bench supply.

 

[John Larkin]

On Mon, 14 Feb 2022 16:50:05 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:

John Larkin Shithead wrote:
==================
Peeler <trol...@valid.invalid
wrote

Generating lame, profane insults is a common skill set. How\'s the pay?


** Why don\'t YOU tell us ??


.... Phil

The nasty-lame level is really high lately. Maybe is a long-covid side
effect.

--

If a man will begin with certainties, he shall end with doubts,
but if he will be content to begin with doubts he shall end in certainties.
Francis Bacon

 

[Commander Kinsey]

On Mon, 14 Feb 2022 12:22:30 -0000, Paul <nospam@needed.invalid> wrote:

On 2/13/2022 5:33 PM, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:

On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ

Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?

Maybe it\'s an AC battery? They are very useful for grid storage applications as long as you can control the phase.

What makes you think that component is a capacitor? I\'m assuming you drew the schematic.

I\'ve learned from someone on Quora that it\'s actually a PTC Fuse - a resettable semiconductor fuse.

The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it\'s to stop a busted battery from being overcharged when a cell has died.

The shape of the edge of the device,
hints that it is not a disc capacitor.

One reason for that, is the material the yellow
thing is dipped in, is a hell of a lot harder,
than the softer stuff used on the older disc caps.
The yellow material might be intended to be
flame proof or the like.

It is shinier than the disk capacitors.

You say \"older\" - don\'t they make them anymore?

 

[Commander Kinsey]

On Mon, 14 Feb 2022 13:41:10 -0000, trader_4 <trader4@optonline.net> wrote:

On Sunday, February 13, 2022 at 5:34:03 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote:
On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ

Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?

Maybe it\'s an AC battery? They are very useful for grid storage applications as long as you can control the phase.

What makes you think that component is a capacitor? I\'m assuming you drew the schematic.

I\'ve learned from someone on Quora that it\'s actually a PTC Fuse - a resettable semiconductor fuse.

The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it\'s to stop a busted battery from being overcharged when a cell has died.

It\'s also not exactly what I\'d call a charger. It\'s more of a charging indicator
circuit. It takes DC input and puts it straight to the battery through a diode.
The rest is there apparently for the two LEDS that show power on and charging.

Yeah, very cheap cordless drill, doesn\'t even have gears. It has hammer action, but at 550rpm that\'s ridiculous. Also can only do a few holes in bricks before the battery goes flat. Maybe it\'ll work better when I introduce the motor to Li Ion....

 

[Commander Kinsey]

On Mon, 14 Feb 2022 18:17:38 -0000, Rick C <gnuarm.deletethisbit@gmail.com> wrote:

On Monday, February 14, 2022 at 1:32:58 AM UTC-5, Commander Kinsey wrote:
On Mon, 14 Feb 2022 04:30:57 -0000, Rick C <gnuarm.del...@gmail.com> wrote:

On Sunday, February 13, 2022 at 10:04:23 PM UTC-5, Commander Kinsey wrote:
On Mon, 14 Feb 2022 01:24:36 -0000, Rick C <gnuarm.del...@gmail.com> wrote:

On Sunday, February 13, 2022 at 7:47:42 PM UTC-5, Commander Kinsey wrote:
On Mon, 14 Feb 2022 00:10:47 -0000, Rick C <gnuarm.del...@gmail.com> wrote:

On Sunday, February 13, 2022 at 6:08:03 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 23:02:03 -0000, Rick C <gnuarm.del...@gmail.com> wrote:

On Sunday, February 13, 2022 at 5:34:04 PM UTC-5, Commander Kinsey wrote:
On Sun, 13 Feb 2022 20:55:51 -0000, Rick C <gnuarm.del...@gmail.com> wrote:

On Sunday, February 13, 2022 at 3:33:49 PM UTC-5, Commander Kinsey wrote:
https://imgur.com/a/b8l5qKQ

Look at the circuit diagram. The positive of the battery is only connected through a capacitor. How can a capacitor possibly pass DC current to allow the battery to charge?

Maybe it\'s an AC battery? They are very useful for grid storage applications as long as you can control the phase.

What makes you think that component is a capacitor? I\'m assuming you drew the schematic.
I\'ve learned from someone on Quora that it\'s actually a PTC Fuse - a resettable semiconductor fuse.

The second image in the link shows a brown disk, which I thought was a ceramic capacitor. Looks like it\'s to stop a busted battery from being overcharged when a cell has died.

It won\'t do that. It is simply a fuse that prevents too high a current from flowing, such as if you connected the battery backwards.
Surely a higher current would flow if the battery became 9 cells instead of 10 because one failed and became zero volts? Ever tried charging a car battery with 14V when it only contains 5 working cells? The others boil.
I\'m not sure what this circuit is supposed to do. It doesn\'t look right to me.
It\'s the (5 hour) charger for a very cheap cordless drill. The input is a 14.4V wall wart. The output is to a pack of NiCad cells. It\'s worked fine for years, until I can no longer find replacement NiCad cells, so I\'m converting the battery packs to LiIon.

My point is this circuit isn\'t setting the voltage or limiting current other than through the fuse.
It will be limited by the wall wart, which is a basic transformer and diodes. Since it\'s a 5 hour charge, it won\'t harm the battery to just keep going.
It appears to be a couple of LEDs that indicate the battery is charging and/or has power.
Yes, the battery is basically just charged through the diode and fuse.
The diode will prevent the transistor from ever turning on more than a tiny amount, but with the gain of the transistor the red LED is turned on with a small current in the transistor BE path. It could be more clear if you redraw it with the base on the right, the resistor to the right of that and the diode across the two. The two resistors and the green LED probably should be on the left, where power comes in. That\'s all they do is indicate the presence of power.
Yeah it was just a quick sketch to try to understand it.
In any event, it is the wall wart that would seem to be doing all the work of charging the battery, setting the max current and the max voltage just by having a significant series resistance most likely.
Ah, you beat me to it.
That\'s why the fuse is not needed for a shorted cell. Being at 11V instead of 14V isn\'t enough to make the current jump so much. A short or reversed battery is a different matter.
Unless NiCads are vastly different to car batteries, one shorted cell makes a hell of a lot more current flow.

THE WALL WART LIMITS THE CURRENT AND PREVENTS ANY ISSUES FROM A SINGLE SHORTED CELL.

Is that clear?
Yes, so why have the semiconductor fuse at all?

[other groups reinstated to stop you limiting the audience - others may be reading this in another group]
Oh, you use google groups. My god man get a newsreader program.

As I said, when you reverse connect the battery, you double the voltage in the circuit. Rather than having a difference of a couple of volts in the EMF opposing the current, you now have a voltage that is perhaps 10 times that total. Yeah, that\'s going to push some unreasonable current though the power pack, so the fuse is needed.
Since the battery pack, like any cordless drill, has a semicircle shaped connector, it cannot possibly be connected backwards.

Did the guy designing the board know that would be the case?

Well I guess the board could be used for many things. It\'s voltage dependant or the LEDs would fail, so it has to be used a for a roughly 14.4V battery pack, which is usually a drill.

> Even connecting a shorted battery is much worse than a single shorted cell. I don\'t get why you are arguing this.

Never heard of a shorted battery. Not all the cells at once.

 

[Phil Allison]

Commander Kinsey wrote:
=====================

Never heard of a shorted battery. Not all the cells at once.

** Happens regularly with NiCd cells.

The pak will read near zero volts and refuse to charge normally.
Some of the cells may show reverse voltage - up 2 V.

Other cells may have a hard short - Cadmium whiskers shorting the plates.
Google it - fuckhead.


....... Phil

 

[Rick C]

On Monday, February 14, 2022 at 6:35:20 PM UTC-5, palli...@gmail.com wrote:

gnuarm.delusional MORON rote:

=========================
The reality is the 1 amp diode is there to limit the current through the transistor
base and so the collector which feeds the LED. So the 1amp diode is limiting the LED current.
** TOTAL CRAP YOU IDIOT

It senses battery charge current.
At a low enough value, the BJT will turn off and the LED go out.

You didn\'t understand a thing I wrote, did you? DIODE. I\'m talking about the DIODE.

The BE junction of the transistor and a resistor are across the diode. This way as the current to the battery increases, the diode limits the voltage across the BE junction and resistor, limiting the increase in BE current and therefore the current in the collector and the LED. Otherwise the LED current would vary a great deal more than it does in this circuit which allows the LED to light more evenly during the charging time.

--

Rick C.

++- Get 1,000 miles of free Supercharging
++- Tesla referral code - https://ts.la/richard11209

 

[Jasen Betts]

On 2022-02-17, Rick C <gnuarm.deletethisbit@gmail.com> wrote:

On Thursday, February 17, 2022 at 7:01:03 AM UTC-5, Jasen Betts wrote:
On 2022-02-17, Rick C <gnuarm.del...@gmail.com> wrote:

Yes, exactly. That\'s why it was disingenuous to post about the switched supplies. Saying, \"nowadays they\'re electronic\" would appear to be saying the transformerless supplies are not in use which is not correct.
Never looked inside one in great detail. I assumed they were switched mode, since a £4 LED bulb from China is. Never tried looking inside a tiny one, like a plug in USB PSU.

The light bulb has to be a switched device. Transformerless units
waste a fair amount of power. Lightbulbs need to be efficient as they
consume a fair amount of power and they also need to regulate the
current.
They consume a few watts, tens at most. not a lot of power.

a capacitive dropper is inherently current limited.

\"A few watts\" in most light bulbs is a lot more than a cell phone charger puts out.

Phone charger 2.5W to 15W. LED lamp 3W to 30W. Same ballpark.

The purpose of LED light bulbs is to save power. Giving up 20% or
more to the dissipative elements in a dropper makes the bulb
significantly less efficient.

So does overdriving the LEDs, but they do that to save money.
where are you getting 20% ?


> No one buys cell phone chargers by their efficiency.

Noone wants one that runs smoking hot. Everyone wants an efficient phone charger.

> Being current limited is of no utility in this case. When that cheap capacitor in the cheap power supply fails, the output becomes high voltage frying devices and people. It only takes a few mA to stop the heart.

What are you on about now?



--
Jasen.

 

[Jasen Betts]

On 2022-02-19, Commander Kinsey <CK1@nospam.com> wrote:

On Fri, 18 Feb 2022 20:08:31 -0000, Jasen Betts <usenet@revmaps.no-ip.org> wrote:

On 2022-02-18, Commander Kinsey <CK1@nospam.com> wrote:
On Fri, 18 Feb 2022 12:13:35 -0000, Jasen Betts <usenet@revmaps.no-ip.org> wrote:

On 2022-02-17, Rick C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, February 17, 2022 at 7:01:03 AM UTC-5, Jasen Betts wrote:
On 2022-02-17, Rick C <gnuarm.del...@gmail.com> wrote:

Yes, exactly. That\'s why it was disingenuous to post about the switched supplies. Saying, \"nowadays they\'re electronic\" would appear to be saying the transformerless supplies are not in use which is not correct.
Never looked inside one in great detail. I assumed they were switched mode, since a £4 LED bulb from China is. Never tried looking inside a tiny one, like a plug in USB PSU.

The light bulb has to be a switched device. Transformerless units
waste a fair amount of power. Lightbulbs need to be efficient as they
consume a fair amount of power and they also need to regulate the
current.
They consume a few watts, tens at most. not a lot of power.

a capacitive dropper is inherently current limited.

\"A few watts\" in most light bulbs is a lot more than a cell phone charger puts out.

Phone charger 2.5W to 15W. LED lamp 3W to 30W. Same ballpark.

A phone battery is 4V. 15 W would be charging it at 4A, you\'d get an explosion.

the phone \"charger\" label says 15W but when I measured it was closer to 13w, I guess
that\'s why it hasn\'t exploded yet.

Even my high spec 18650 cells recommend charging at 1.5A. And those aren\'t enclosed in a phone.

Well it\'s a fast charger. so it charges at about 1C (which seems to
also be the fast-charge rate for lithium ion)

The purpose of LED light bulbs is to save power. Giving up 20% or
more to the dissipative elements in a dropper makes the bulb
significantly less efficient.

So does overdriving the LEDs, but they do that to save money.

It doesn\'t save money. I bought Cree (shittest company ever) bulbs, they lasted 1 month due to getting so fucking hot they couldn\'t be touched comfortably for even half a second. I sent them back 5 times, costing them a fortune.

Saves the manufacturer money. they can achieve brihtness while using
less material, also they can sell more if they don\'t last too long.

They won\'t sell more. They either get them returned costing them
money, or the customer never uses that brand again.

Maybe if the customer can remember when they purchased the lamp,
and notices the gradual dimming. pretty much the only place that has
high efficiency LED lamps is Dubai.

--
Jasen.

 

[Commander Kinsey]

On Mon, 21 Feb 2022 03:52:52 -0000, Jasen Betts <usenet@revmaps.no-ip.org> wrote:

On 2022-02-19, Commander Kinsey <CK1@nospam.com> wrote:
On Fri, 18 Feb 2022 20:08:31 -0000, Jasen Betts <usenet@revmaps.no-ip..org> wrote:

On 2022-02-18, Commander Kinsey <CK1@nospam.com> wrote:
On Fri, 18 Feb 2022 12:13:35 -0000, Jasen Betts <usenet@revmaps.no-ip.org> wrote:

On 2022-02-17, Rick C <gnuarm.deletethisbit@gmail.com> wrote:
On Thursday, February 17, 2022 at 7:01:03 AM UTC-5, Jasen Betts wrote:
On 2022-02-17, Rick C <gnuarm.del...@gmail.com> wrote:

Yes, exactly. That\'s why it was disingenuous to post about the switched supplies. Saying, \"nowadays they\'re electronic\" would appear to be saying the transformerless supplies are not in use which is not correct.
Never looked inside one in great detail. I assumed they were switched mode, since a £4 LED bulb from China is. Never tried looking inside a tiny one, like a plug in USB PSU.

The light bulb has to be a switched device. Transformerless units
waste a fair amount of power. Lightbulbs need to be efficient as they
consume a fair amount of power and they also need to regulate the
current.
They consume a few watts, tens at most. not a lot of power.

a capacitive dropper is inherently current limited.

\"A few watts\" in most light bulbs is a lot more than a cell phone charger puts out.

Phone charger 2.5W to 15W. LED lamp 3W to 30W. Same ballpark.

A phone battery is 4V. 15 W would be charging it at 4A, you\'d get an explosion.

the phone \"charger\" label says 15W but when I measured it was closer to 13w, I guess
that\'s why it hasn\'t exploded yet.

Even my high spec 18650 cells recommend charging at 1.5A. And those aren\'t enclosed in a phone.

Well it\'s a fast charger. so it charges at about 1C (which seems to
also be the fast-charge rate for lithium ion)

Ah ok, mine were 1/2C, Panasonic so I assumed the best.

It\'s really hard to get 18650 in the UK. Ebay banned them (but not other Li Ion sizes!) and I could only find 1 other place that sold them, and three others at triple price! The place I got the tabbed ones from had a notice saying \"Samsung has publicly denounced the selling of tagged batteries to end users\", but they sold me them anyway. Do Samsung think we\'re idiots? The batteries even have on the side \"this must not be installed or used by a customer\". Er mustn\'t be used?!

The purpose of LED light bulbs is to save power. Giving up 20% or
more to the dissipative elements in a dropper makes the bulb
significantly less efficient.

So does overdriving the LEDs, but they do that to save money.

It doesn\'t save money. I bought Cree (shittest company ever) bulbs, they lasted 1 month due to getting so fucking hot they couldn\'t be touched comfortably for even half a second. I sent them back 5 times, costing them a fortune.

Saves the manufacturer money. they can achieve brihtness while using
less material, also they can sell more if they don\'t last too long.

They won\'t sell more. They either get them returned costing them
money, or the customer never uses that brand again.

Maybe if the customer can remember when they purchased the lamp,
and notices the gradual dimming. pretty much the only place that has
high efficiency LED lamps is Dubai.

LED don\'t gradually dim, they just go off.

 

[Rick C]

On Sunday, February 20, 2022 at 11:01:00 PM UTC-5, Jasen Betts wrote:

On 2022-02-19, Commander Kinsey <C...@nospam.com> wrote:

Even my high spec 18650 cells recommend charging at 1.5A. And those aren\'t enclosed in a phone.
Well it\'s a fast charger. so it charges at about 1C (which seems to
also be the fast-charge rate for lithium ion)

For small devices they aren\'t going to spend too much effort on designing the charger. With lithium-ion batteries you can charge at faster rates if you tailor the rate to the state of charge during the charging process. With EVs they put a lot more effort into the design of the battery management system. There they tailor the charging rate to the temperature and the state of charge so the battery charge rate balances time to charge with battery life under all conditions. My car can reach 1.5C charging rate and other Tesla models reach 3C.

--

Rick C.

+-++ Get 1,000 miles of free Supercharging
+-++ Tesla referral code - https://ts.la/richard11209