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What's the short circuit current of a 9V battery?

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Lewis Cobb

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Mar 1, 2000, 3:00:00 AM3/1/00
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Hi and thanks for reading this posting. I'm wondering if anyone has some
data on what the short circuit current is for a typical 9v alkaline battery?

Or perhaps the range that you could experience with different manufacturers
of 9v batteries...

Thanks

Lewis
co...@ee.unb.ca


Science Hobbyist

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Mar 1, 2000, 3:00:00 AM3/1/00
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In article <89hrth$iv5$1...@malakbel.unb.ca>,

co...@ee.unb.ca (Lewis Cobb) wrote:
> Hi and thanks for reading this posting. I'm wondering if anyone has
some
> data on what the short circuit current is for a typical 9v alkaline
battery?


I've seen new batteries go above 10 amps (on a Beckman DVM
w/20A full scale range).

--
((((((((((((((((((( ( ( ( ( (O) ) ) ) ) )))))))))))))))))))
William Beaty bbe...@microscan.com
Software Engineer http://www.microscan.com
Microscan Inc., Renton, WA 425-226-5700 x1135


Sent via Deja.com http://www.deja.com/
Before you buy.

Harry H Conover

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Mar 1, 2000, 3:00:00 AM3/1/00
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Science Hobbyist (bbe...@microscan.com) wrote:
: In article <89hrth$iv5$1...@malakbel.unb.ca>,

: co...@ee.unb.ca (Lewis Cobb) wrote:
: > Hi and thanks for reading this posting. I'm wondering if anyone has
: some
: > data on what the short circuit current is for a typical 9v alkaline
: battery?
:
:
: I've seen new batteries go above 10 amps (on a Beckman DVM
: w/20A full scale range).

I find that value very difficult to accept.

Sadly, I have no 9-Volt transistor batteries on hand to run a test,
but I'll get some and post a follow-up.

My measurement of short-circuit current from 1-1/2 Volt AA and C cells
ran between 800-ma. (AA) and 1.0 Amp (C).

Based on this, I'd estimate the peak current output of a 9-Volt transistor
batter (alkaline type) to be at best 500-600 ma., but I'll get a fresh one
tomorrow and post the measurement result. (Actually, I'm going to buy
6 of them anyway, because my smoke detector batteries are due for
replacement.)

Harry C.

sp...@interlog.com

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Mar 1, 2000, 3:00:00 AM3/1/00
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The renowned Harry H Conover <con...@tiac.net> wrote:

> Based on this, I'd estimate the peak current output of a 9-Volt transistor
> batter (alkaline type) to be at best 500-600 ma., but I'll get a fresh one
> tomorrow and post the measurement result. (Actually, I'm going to buy
> 6 of them anyway, because my smoke detector batteries are due for
> replacement.)

FYI, 9V Duracell (fresh from Costco, 2003 "best-before" date) gave
(briefly) over 5A output, before polarization began to take its toll.

1 or 2 "Kirkland" AA cells in series gave ~4.7A, it decreased less
quickly.

Interesting info. I put a 1N4004 across a fresh 9V battery for 30 seconds
and it smoked a bit but survived (no heatsinking). If you want
bullet-proof reverse polarity protection, a 3A shunt diode would be a
better bet.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Spehro Pefhany "The Journey is the reward"
sp...@interlog.com
Fax:(905) 271-9838 (small micro system devt hw/sw + mfg)
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

John Devereux

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Mar 1, 2000, 3:00:00 AM3/1/00
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On Wed, 01 Mar 2000 04:40:13 GMT,
sp...@interlog.com wrote:

>The renowned Harry H Conover <con...@tiac.net> wrote:
>
>> Based on this, I'd estimate the peak current output of a 9-Volt transistor
>> batter (alkaline type) to be at best 500-600 ma., but I'll get a fresh one
>> tomorrow and post the measurement result. (Actually, I'm going to buy
>> 6 of them anyway, because my smoke detector batteries are due for
>> replacement.)
>
>FYI, 9V Duracell (fresh from Costco, 2003 "best-before" date) gave
>(briefly) over 5A output, before polarization began to take its toll.
>
>1 or 2 "Kirkland" AA cells in series gave ~4.7A, it decreased less
>quickly.
>
>Interesting info. I put a 1N4004 across a fresh 9V battery for 30 seconds
>and it smoked a bit but survived (no heatsinking). If you want
>bullet-proof reverse polarity protection, a 3A shunt diode would be a
>better bet.

Until someone puts in a NiCad :)

-- John Devereux

jo...@devereux.demon.co.uk

Tony Williams

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Mar 1, 2000, 3:00:00 AM3/1/00
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In article <Na1v4.30221$c7.8...@news1.rdc1.on.wave.home.com>,
<sp...@interlog.com> wrote:

> Interesting info. I put a 1N4004 across a fresh 9V battery for 30 seconds
> and it smoked a bit but survived (no heatsinking). If you want
> bullet-proof reverse polarity protection, a 3A shunt diode would be a
> better bet.

Umm... no Spehro. I really got bitten by that.

Used a (large, IN4000-size) diode to protect
against reverse polarity from a 9v battery in
a handheld instrument. I tested it here many
times with ordinary PP9 zinc-carbon batteries.
Shipped 50 pieces. Customer returned about 15
or 20 as 'not working on receipt' and I had
to bear the cost of replacing the 7106 chips.
Turned out he was using rechargeable batteries
and I suppose that if there is enough current
then there is sufficent volts across the diode
to divert some into the chips. :-((

And note this.....

1. Those 9v battery connectors are so damned obvious.

2. Our enclosed leaflet said 'switch OFF when
replacing batteries'.

3. I used a 3-pin connector for the thermocouple
input, so that the power was OFF when the T/C
was not plugged in.

And STILL that customer managed to blow up chips.

--
Tony Williams.

Mike Monett

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Mar 1, 2000, 3:00:00 AM3/1/00
to

> Tony Williams.

Hi Tony,

Forcing a short circuit is a lousy way of protecting a user-accessible
device. I laugh when a fail-safe method has the potential of generating
arbitrarily large currents. What if the user decided to hook up a car
battery to get longer battry life?

Can you put the diode in series with the load? It would drop the voltage
slightly, but a battery-operated device needs a wide supply tolerance
anyway.

Best Regards,

Michael R. Monett
mailto:mkmo...@hotmail.com

Pat Ford

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Mar 1, 2000, 3:00:00 AM3/1/00
to
build an idiot proof device and god makes a better idiot

Previously, Tony Williams wrote in sci.electronics.design:
{ In article <Na1v4.30221$c7.8...@news1.rdc1.on.wave.home.com>,

{
{ --
{ Tony Williams.
{

--
Pat Ford email: pf...@qnx.com
QNX Software Systems, Ltd. WWW: http://www.qnx.com
(613) 591-0931 (voice) mail: 175 Terence Matthews
(613) 591-3579 (fax) Kanata, Ontario, Canada K2M 1W8


Tony Williams

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Mar 1, 2000, 3:00:00 AM3/1/00
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In article <38BD1F...@hotmail.com>,
Mike Monett <mkmo...@hotmail.com> wrote:

> Hi Tony,

> Forcing a short circuit is a lousy way of protecting a user-accessible
> device. I laugh when a fail-safe method has the potential of generating
> arbitrarily large currents. What if the user decided to hook up a car
> battery to get longer battry life?

> Can you put the diode in series with the load? It would drop the voltage
> slightly, but a battery-operated device needs a wide supply tolerance
> anyway.

This was 20-odd? years ago Mike.... One of the
(many) lumps that some of have to make in order
to 'make our bones' in this job.

I originally did a parallel diode to extend the
life of a zinc-carbon battery as long as possible.
And yes, it was later changed to a series-diode.
The only problem there was deciding on how many
Kv to rate the piv of the diode for. :)

--
Tony Williams.

Keith Wootten

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Mar 1, 2000, 3:00:00 AM3/1/00
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In article <49986b1...@ledelec.demon.co.uk>, Tony Williams
<to...@ledelec.demon.co.uk> writes

>In article <Na1v4.30221$c7.8...@news1.rdc1.on.wave.home.com>,
> <sp...@interlog.com> wrote:
>
>> Interesting info. I put a 1N4004 across a fresh 9V battery for 30 seconds
>> and it smoked a bit but survived (no heatsinking). If you want
>> bullet-proof reverse polarity protection, a 3A shunt diode would be a
>> better bet.
>
> Umm... no Spehro. I really got bitten by that.
>
> Used a (large, IN4000-size) diode to protect
> against reverse polarity from a 9v battery in
> a handheld instrument. I tested it here many
> times with ordinary PP9 zinc-carbon batteries.
> Shipped 50 pieces. Customer returned about 15
> or 20 as 'not working on receipt' and I had
> to bear the cost of replacing the 7106 chips.
> Turned out he was using rechargeable batteries
> and I suppose that if there is enough current
> then there is sufficent volts across the diode
> to divert some into the chips. :-((

[snip]

A Polyfuse might work well here.

Cheers
--
Keith Wootten

James Meyer

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Mar 1, 2000, 3:00:00 AM3/1/00
to
On 1 Mar 2000 01:46:01 GMT, con...@tiac.net (Harry H Conover) wrote:

>Based on this, I'd estimate the peak current output of a 9-Volt transistor
>batter (alkaline type) to be at best 500-600 ma., but I'll get a fresh one
>tomorrow and post the measurement result.
>

> Harry C.
>

A new Radio Shack 9 Volt rectangular battery, part # 23-875, measured
with a Fluke model 73 multimeter shows a peak short circuit current of over 6
Amps for a second or two and over 5 Amps for several seconds after that.

Jim


sp...@interlog.com

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Mar 1, 2000, 3:00:00 AM3/1/00
to
The renowned Tony Williams <to...@ledelec.demon.co.uk> wrote:

> Umm... no Spehro. I really got bitten by that.

> Used a (large, IN4000-size) diode to protect
> against reverse polarity from a 9v battery in
> a handheld instrument. I tested it here many
> times with ordinary PP9 zinc-carbon batteries.
> Shipped 50 pieces. Customer returned about 15

Ouch!!

> or 20 as 'not working on receipt' and I had
> to bear the cost of replacing the 7106 chips.
> Turned out he was using rechargeable batteries
> and I suppose that if there is enough current
> then there is sufficent volts across the diode
> to divert some into the chips. :-((

Ok, it *might* have worked had there been a small
resistor in series with the chip power supply. At 5A
there will be >1V across a 1N400x... that's
the SC current for an alkaline cell, not a NiCd. A
51R resistor would drop only 50mV at the 1mA a 7106
draws, but limit the reverse current to about 10mA.
It's 20-20 hindsight, I know. 8-(

> And note this.....

> 1. Those 9v battery connectors are so damned obvious.
> 2. Our enclosed leaflet said 'switch OFF when
> replacing batteries'.
> 3. I used a 3-pin connector for the thermocouple
> input, so that the power was OFF when the T/C
> was not plugged in.

> And STILL that customer managed to blow up chips.

8-( Probably did other things too, they sound like what we refer to as
"blacksmiths" (no offense intended to actual skilled blacksmiths..).

I've been burned by variations on this in the past... with
thermocouple inputs, I finally had to accept that a certain percentage of
them will meet an untimely end with 240VAC connected across them, there is
really no practical way to protect them at a reasonable cost. Best you can
do is a series fuse or fusible resistor and back-to-back diodes, and that
still has to come back to the factory to be repaired, so it it's scarcely
better than nothing (but with lots of extra parts to fail etc.).

I'm writing up a somewhat related protection scheme for a magazine, I'll
post the URL (months from now) when it shows up in print, if anyone's
interested.

Robert Strand

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Mar 2, 2000, 3:00:00 AM3/2/00
to
Mike Monett wrote:

> Forcing a short circuit is a lousy way of protecting a user-accessible
> device. I laugh when a fail-safe method has the potential of generating
> arbitrarily large currents. What if the user decided to hook up a car
> battery to get longer battry life?

I think this method is OK if you can guarantee it doesn't cause any secondary
problems. For a car there should be a line fuse, so hopefully the user learns to
plug things in the correct way because otherwise he has to fork out for a fuse
each time (aluminium foil fuse users can get what they get). Even with a fuse
I've seen PCB tracks taken out because the undersized tracks can't cope with the
fault condition.

> Can you put the diode in series with the load? It would drop the voltage
> slightly, but a battery-operated device needs a wide supply tolerance
> anyway.

The drop of the series diode is a bit of a bummer, especially if you have
regulators on board, the effective battery life starts to diminish
unnecessarily. For devices that have a fairly low run current, you can put a low
value resistor in series with the battery and keep the reverse diode at the
circuit side. Here, the voltage drop across the resistor is low during normal
operation and the fault current is kept to a safe level.

Regards
Rob

Mike Monett

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Mar 2, 2000, 3:00:00 AM3/2/00
to
Tony Williams wrote:

[...]

> This was 20-odd? years ago Mike.... One of the
> (many) lumps that some of have to make in order
> to 'make our bones' in this job.
>
> I originally did a parallel diode to extend the
> life of a zinc-carbon battery as long as possible.
> And yes, it was later changed to a series-diode.
> The only problem there was deciding on how many
> Kv to rate the piv of the diode for. :)

> Tony Williams.

Heh heh!

Malcolm

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Mar 3, 2000, 3:00:00 AM3/3/00
to
I once back in 1981 vaporised a BC109 transistor leg and melted the
veroboard.
strange thing was that there wasn't anything wrong with the layout either!!!
just a freak occurrence, dodgy tranny etc.
made me look I can tell you
regards malcolm


Lewis Cobb <co...@ee.unb.ca> wrote in message
news:89hrth$iv5$1...@malakbel.unb.ca...


> Hi and thanks for reading this posting. I'm wondering if anyone has some
> data on what the short circuit current is for a typical 9v alkaline
battery?
>

Paul Taylor

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Mar 6, 2000, 3:00:00 AM3/6/00
to
"Lewis Cobb" <co...@ee.unb.ca> wrote in message
news:89hrth$iv5$1...@malakbel.unb.ca...
> Hi and thanks for reading this posting. I'm wondering if anyone has some
> data on what the short circuit current is for a typical 9v alkaline
battery?
>
> Or perhaps the range that you could experience with different
manufacturers
> of 9v batteries...
>
> Thanks
>
> Lewis
> co...@ee.unb.ca

I've noted in my Psion that the internal resistance of a charged alkaline
PP3 = 3 ohms.
This was from H&H, I think.
9V / 3R = 3A

Paul.

Mike Monett

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Mar 6, 2000, 3:00:00 AM3/6/00
to
Paul Taylor wrote:
>
> "Lewis Cobb" <co...@ee.unb.ca> wrote in message
> news:89hrth$iv5$1...@malakbel.unb.ca..
> > Hi and thanks for reading this posting. I'm wondering if anyone has some
> > data on what the short circuit current is for a typical 9v alkaline
> battery?
> >
> > Or perhaps the range that you could experience with different
> manufacturers
> > of 9v batteries...
> >
> > Thanks
> >
> > Lewis
> > co...@ee.unb.ca
>
> I've noted in my Psion that the internal resistance of a charged alkaline
> PP3 = 3 ohms.
> This was from H&H, I think.
> 9V / 3R = 3A
>
> Paul.

Hi gang,

Some nicads are capable of supplying a lot more current.

Has anyone posted the story about the World Model Train Racing
Championship in Germany? A drag race to see who can send a toy train
down a track the fastest.

The winner got almost 5 hp each from two 1.5-inch diameter motors
running 3,682W, or 94A at 60V using 40 Panasonic P 180 SCR-Z Nicads.

You can see their ultimate toy at:

http://www.manufacturing.net/magazine/dn/archives/2000/dn0207.00/dn0207.00/03ult.htm

Roy Schmaus

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Mar 7, 2000, 3:00:00 AM3/7/00
to
On Mon, 6 Mar 2000 20:30:07 -0000, "Paul Taylor"
<p.ta...@ukonline.co.uk> wrote:

>"Lewis Cobb" <co...@ee.unb.ca> wrote in message

>news:89hrth$iv5$1...@malakbel.unb.ca...


>> Hi and thanks for reading this posting. I'm wondering if anyone has some
>> data on what the short circuit current is for a typical 9v alkaline
>battery?


It must be a lot more than I used to think. Dropped a used one from
the smoke detector at home into my pants pocket while installing a
replacement.. Something felt awfully hot in there after a while,
apparently the 'old' battery had been shorted by some keys and still
had enough in it to heat the battery.

You might try connecting a 10A meter across a known good battery
for a short time. It will cook the battery but at least you will
have your data.


Roy Schmaus
http://www.ee.ualberta.ca/~schmaus/


Boris Mohar

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Mar 9, 2000, 3:00:00 AM3/9/00
to


If you have money to burn than take two 9V batteries and plug them into each
other. Talk about emergency hand warmers!


Regards,

Boris Mohar

Viatrack Printed Circuit Designs

Al, N2NKB

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Mar 10, 2000, 3:00:00 AM3/10/00
to

>>You might try connecting a 10A meter across a known good battery
>>for a short time. It will cook the battery but at least you will
>>have your data.

You may even blow out the meter's 10+ A fuse! I've even seen miniature button cells that have more than
10A short circuit current.
Al

John Woodgate

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Mar 10, 2000, 3:00:00 AM3/10/00
to
<JnXx4.2262$lA4.1...@bgtnsc05-news.ops.worldnet.att.net>, Al, N2NKB
A NiCd PP3 (8.4 V, nominally 9 V) has a typical short-circuit current of
90 A when newly charged. DON'T TRY THIS AT HOME!!! THE BATTERY MAY
EXPLODE. Two of my test samples did (but I tested them inside a metre of
steel pipe).
--
Regards, John Woodgate, OOO - Own Opinions Only. Phone +44 (0)1268 747839
Fax +44 (0)1268 777124. http://www.jmwa.demon.co.uk
I wanted to make a fully-automated nuclear-powered trawler,
but it went into spontaneous fishing.

jenish...@gmail.com

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Jun 18, 2017, 11:22:50 AM6/18/17
to
i need u help

Cursitor Doom

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Jun 18, 2017, 12:21:20 PM6/18/17
to
On Sun, 18 Jun 2017 08:22:43 -0700, jenishshah550 wrote:

> i need u help

Why don't you measure it? It's entirely dependent on its internal
resistance. Basic stuff 101.

Jeff Liebermann

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Jun 18, 2017, 1:11:01 PM6/18/17
to
On Sun, 18 Jun 2017 08:22:43 -0700 (PDT), jenish...@gmail.com
wrote:

>i need u help

Before or after the explosion?
<http://802.11junk.com/jeffl/pics/Duracell/>
The battery terminals were accidentally shorted by the owner. The
batteries were new and at full capacity. If you're planning on
measuring the short circuit current, you might first consider this
problem.

Which 9V battery chemistry do you need help with? Carbon-zinc,
alkaline, NiCd, NiMh, or LiIon? A specific battery maker name and
part number would be helpful.

Also, detonators vary in how much current they need to reliably
initiate an explosion. The minimum is about 90ma which tend to be
rather dangerous in RF fields. Typical is about 500ma. There is an
upper limit to the current. If too high, the ignition wire will fuse
and break before it has time to get hot enough to detonate the cap.
Check the detonator specifications. This article should help:
<https://www.linkedin.com/pulse/detonators-power-sources-john-howell>

IP: 27.34.21.181 Kathmandu, Nepal.
Still rebuilding after the earthquake?
<http://www.foxnews.com/world/2017/04/25/look-at-nepal-progress-in-earthquake-recovery.html>


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Cursitor Doom

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Jun 18, 2017, 4:43:09 PM6/18/17
to
On Sun, 18 Jun 2017 10:10:54 -0700, Jeff Liebermann wrote:

> On Sun, 18 Jun 2017 08:22:43 -0700 (PDT), jenish...@gmail.com wrote:
>
>>i need u help
>
> Before or after the explosion?
> <http://802.11junk.com/jeffl/pics/Duracell/>
> The battery terminals were accidentally shorted by the owner. The
> batteries were new and at full capacity. If you're planning on
> measuring the short circuit current, you might first consider this
> problem.

A short duration pulse, then!

> Also, detonators vary in how much current they need to reliably initiate
> an explosion.

My god you're in a suspicious mood today, Jeffrey! :-D

Jeff Liebermann

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Jun 18, 2017, 8:10:23 PM6/18/17
to
On Sun, 18 Jun 2017 10:10:54 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:

If you really want to know the short circuit current, you can measure
it indirectly. Make sure the battery if fairly new and at full
capacity. Measure the voltage across the battery with nothing
connected.

Connect about a 100 ohm load resistor, in series with an ammeter.
Connect this combination across the battery terminals. Quickly
measure the current and voltage with this load applied. The voltage
will drop is due to a combination of battery depletion and internal
resistance. Hopefully, most of it will be internal resistance.
Calculate the internal resistance as below:

If the current is 100ma and the voltage drops from 9.0v to 8.5v, then
the short circuit current would be:
Voltage_drop_percent = ((9.0 - 8.5) / 9.0) = 0.056
Short_circuit_current = 0.1A / 0.056 = 1.8A

David Eather

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Jun 18, 2017, 9:15:21 PM6/18/17
to
On Mon, 19 Jun 2017 01:22:43 +1000, <jenish...@gmail.com> wrote:

get hold of the highest resolution multimeter you can - it also helps if
it is accurate but resolution is more important in this case.


measure the open circuit voltage of the battery call it V1

place a 330 ohm resistor across the battery. call it R

There is nothing magical about 330 ohm - just that a 1/4 watt resistor
won't burn out at 9v.

A lower resistor value will make it easier to get a good reading but it
has to have a sufficient power rating eg 180 ohm 1/2 watt or 82 ohm 1
watt or 18 ohm 5 watt. Also you will have to be quicker to take your
readings.

measure the voltage across the battery now. call it V2

The internal resistance of the battery is (V1-V2) / (V2 / R) = Rint

The short circuit current is V2 / Rint

and it will be surprisingly high - but only for short durations




--
Using Opera's mail client: http://www.opera.com/mail/

Brian Howie

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Jun 19, 2017, 12:49:59 PM6/19/17
to
In message <b2abf7bd-deaf-4be4...@googlegroups.com>,
jenish...@gmail.com writes
>i need u help

I tried 2 of those Duracell Alakaline oblong ones 6LR61 / MN1604 /
PP3. I replaced the ones in my smoke alarms as they've reached their
shelf life date.

One was 1.2A and the other 1.0 Amp .I used an Avometer

http://www.farnell.com/datasheets/1746909.pdf

Data sheet suggests a resistance of about 3ohm , so it should be nearer
3A unless it's non-linear or mine are getting old.

Brian
--
Brian Howie

Phil Allison

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Jun 19, 2017, 7:57:35 PM6/19/17
to
Brian Howie wrote:

------------------------
>
> I tried 2 of those Duracell Alakaline oblong ones 6LR61 / MN1604 /
> PP3. I replaced the ones in my smoke alarms as they've reached their
> shelf life date.
>
> One was 1.2A and the other 1.0 Amp .I used an Avometer
>
> http://www.farnell.com/datasheets/1746909.pdf
>
> Data sheet suggests a resistance of about 3ohm , so it should be nearer
> 3A unless it's non-linear or mine are getting old.
>

** Dunno if you tested *fresh* batteries or not, but most fresh 9V alkalines have an ESR under 1 ohm.

The initial cct current current is 10 amps.

Forget the published specs, do measurements.




.... Phil



John S

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Jun 19, 2017, 10:52:17 PM6/19/17
to
Good data.

I measured a Rayovac 6LF22 with a date of Nov 2020. They say they hold
up 5 years in storage so they have 3 years to go. It was fresh out of
the package. It had an open circuit voltage of 9.64V.

I set my DVM on the 20A range and probed the terminals. I got 2.54A.

John S

Phil Allison

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Jun 20, 2017, 12:01:27 AM6/20/17
to
John S wrote:

-----------------

>
> Good data.
>
> I measured a Rayovac 6LF22 with a date of Nov 2020. They say they hold
> up 5 years in storage so they have 3 years to go. It was fresh out of
> the package. It had an open circuit voltage of 9.64V.
>
> I set my DVM on the 20A range and probed the terminals. I got 2.54A.
>

>
** You need to measure the voltage at the batt terminals at the *same* time.

I bet you will be very surprised how it is not SHORTED.

I just checked a no-brand alkaline (from Aldi) and got a reading of 6.7amps.

Quite repeatable with a short rest in between.



.... Phil

Phil Allison

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Jun 20, 2017, 5:06:20 AM6/20/17
to
Al N2NKB wrote:

-----------------

>
> You may even blow out the meter's 10+ A fuse!
> I've even seen miniature button cells that have more than
> 10A short circuit current.
>


** Dunno what your idea of a *miniature* button cell is but no way will any Lithium coin cells do that.

Even NiMH ones do about 2amps at best.


.... Phil

George Herold

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Jun 20, 2017, 10:27:43 AM6/20/17
to
Any idea what the input impedance of the DMM is? (It most likely
has a big ass-fuse* in series.)


George H.
*after Speff's xkcd comment a week or so ago I now also find myself moving
the hyphen.

tabb...@gmail.com

unread,
Jun 20, 2017, 4:25:19 PM6/20/17
to
Burden voltage is in pretty much every meter's specs.
I can't imagine what an ass-fuse is. Does it blow if you get the runs?


NT

John S

unread,
Jun 21, 2017, 11:23:29 AM6/21/17
to
Sorry, George, I've lost the manual. It is a Metex ME-11. I tried to
measure it but didn't get a stable reading so I don't trust the 30mohm
figure I got. At 20A something(s) in the meter would be dissipating 12W
if it had that much resistance.

John S


John S

unread,
Jun 21, 2017, 1:27:52 PM6/21/17
to
On 6/20/2017 9:27 AM, George Herold wrote:
I applied 2.47A to the probes from a linear lab supply. I measured the
voltage at the probe tips and got .39V which gives .157 ohms. This is
even more unreasonable than my resistance measurement. If it is even
close to reality, I doubt that the 20A range would support even 10A for
long.

John S (raining on my own parade)

tom

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Jun 21, 2017, 5:00:13 PM6/21/17
to

"John S" <Sop...@invalid.org> wrote in message
news:oiea3n$jvj$2...@dont-email.me...
The probe leads probably make up for most of the 0.157 ohms.

Measure the voltage right at the meter input.

Regards


Phil Allison

unread,
Jun 21, 2017, 5:25:21 PM6/21/17
to
John S wrote:

-------------------
>
>
> I applied 2.47A to the probes from a linear lab supply. I measured the
> voltage at the probe tips and got .39V which gives .157 ohms. This is
> even more unreasonable than my resistance measurement. If it is even
> close to reality, I doubt that the 20A range would support even 10A for
> long.
>
>

** The 20 amp shunt is gonna be 10 milliohms.

Likely there is a fuse in series with not too good contacts accounting for the unstable reading. The probes and leads are adding way more.

It is VERY clear to me you are NOT testing fresh 9V alkaline batteries.

If you test a fresh Energizer, it will read close to 10 amps.



.... Phil

John S

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Jun 21, 2017, 10:56:23 PM6/21/17
to
On 6/21/2017 4:25 PM, Phil Allison wrote:
> John S wrote:
>
> -------------------
>>
>>
>> I applied 2.47A to the probes from a linear lab supply. I measured
>> the voltage at the probe tips and got .39V which gives .157 ohms.
>> This is even more unreasonable than my resistance measurement. If
>> it is even close to reality, I doubt that the 20A range would
>> support even 10A for long.
>>
>>
>
> ** The 20 amp shunt is gonna be 10 milliohms.
>
> Likely there is a fuse in series with not too good contacts
> accounting for the unstable reading. The probes and leads are adding
> way more.

Probably. But how much of a short circuit will the OP be able to provide?

> It is VERY clear to me you are NOT testing fresh 9V alkaline
> batteries.
>
> If you test a fresh Energizer, it will read close to 10 amps.

How fresh is fresh? I was only trying to provide info with what I had on
hand. I'm not going to go to Batteries R Us and buy an Energizer just to
test and post here. You are welcome to do so. Please do. Your data would
be well accepted, I'm sure.

Thanks for your advice.
John S

>
>
> .... Phil
>

John S

unread,
Jun 21, 2017, 11:10:40 PM6/21/17
to
On 6/18/2017 10:22 AM, jenish...@gmail.com wrote:
> i need u help
>


What's the difference in a duck?

Phil Allison

unread,
Jun 22, 2017, 2:11:03 AM6/22/17
to
John S wrote:

-------------------

> >>
> >
> > ** The 20 amp shunt is gonna be 10 milliohms.
> >
> > Likely there is a fuse in series with not too good contacts
> > accounting for the unstable reading. The probes and leads are adding
> > way more.
>
> Probably. But how much of a short circuit will the OP be able to provide?
>

** Irrelevant.



> > It is VERY clear to me you are NOT testing fresh 9V alkaline
> > batteries.
> >
> > If you test a fresh Energizer, it will read close to 10 amps.
>
> How fresh is fresh?
>


** Less than 2 years old.


> I was only trying to provide info with what I had on
> hand.


** But it was wrong.

> I'm not going to go to Batteries R Us and buy an Energizer just to
> test and post here.

** Then don't post at all.


> You are welcome to do so. Please do. Your data would
> be well accepted, I'm sure.
>


** Have you not read this thread at all ???

Might be an idea to do so now.


...... Phil

Spehro Pefhany

unread,
Jun 22, 2017, 8:35:58 AM6/22/17
to
On Sun, 18 Jun 2017 10:10:54 -0700, the renowned Jeff Liebermann
<je...@cruzio.com> wrote:

>On Sun, 18 Jun 2017 08:22:43 -0700 (PDT), jenish...@gmail.com
>wrote:
>
>>i need u help
>
>Before or after the explosion?
><http://802.11junk.com/jeffl/pics/Duracell/>

John Woodgate (here, some years ago) reported a violent explosion of a
NiCd 9V battery and 90A SC current.

--sp

--
Best regards,
Spehro Pefhany

George Herold

unread,
Jun 22, 2017, 9:01:33 AM6/22/17
to
On Thursday, June 22, 2017 at 2:11:03 AM UTC-4, Phil Allison wrote:
> John S wrote:
>
> -------------------
>
> > >>
> > >
> > > ** The 20 amp shunt is gonna be 10 milliohms.
> > >
> > > Likely there is a fuse in series with not too good contacts
> > > accounting for the unstable reading. The probes and leads are adding
> > > way more.
> >
> > Probably. But how much of a short circuit will the OP be able to provide?
> >
>
> ** Irrelevant.
>
>
>
> > > It is VERY clear to me you are NOT testing fresh 9V alkaline
> > > batteries.
> > >
> > > If you test a fresh Energizer, it will read close to 10 amps.
> >
> > How fresh is fresh?
> >
>
>
> ** Less than 2 years old.
>
>
> > I was only trying to provide info with what I had on
> > hand.
>
>
> ** But it was wrong.
>
> > I'm not going to go to Batteries R Us and buy an Energizer just to
> > test and post here.
>
> ** Then don't post at all.
Nah, keep posting. Interpreting measurements is 1/2 the fun.
I never knew 9V batteries had such low internal resistance.

George H.

DemonicTubes

unread,
Jun 22, 2017, 11:57:37 AM6/22/17
to
Impressed this thread is still going over 17 years later...

Here is what you can do with 244 9V batteries:
https://youtu.be/8hwLHdBTQ7s

This guy tries to make a Jacob's Ladder:
https://youtu.be/c0QvbThCxm4

Jeff Liebermann

unread,
Jun 22, 2017, 12:45:00 PM6/22/17
to
I tried to duplicate the exploding 9V Duracell alkaline battery and
failed. I bought a brand new battery and shorted the contacts with
two alligator clips and some #12 awg soldered electrical wire. It got
quite hot, belched white smog, and made some ominous hissing noises,
but no explosion. I should probably try it again. This makes me
suspect that the exploding battery was either defective or a
counterfeit. The vent hole was probably sized to sloooooowly leak any
gasses produced inside the battery. When faced with the rapid
outgassing from a shorted battery, the tiny hole just couldn't handle
the flow rate, allowing pressure to build up inside the cell. Another
possible is that a tiny piece of something plugged the hole.

I've never tried shorting a 9V NiCd and have no idea how it will
react. However, I've done the reverse. I wasted quite a bit of time
testing how quickly I could recharge a NiCd cell. I was working with
single cells because such high current charging would not work without
a balance charger in multi-cell batteries like the 9V. Starting with
a discharged cell, I could cram fairly large charging currents (10C)
into a cell without heating, outgassing, or ruining the cell. However,
I had to stop at about 90% of charge or the battery would start
becoming hot. If I continued, the battery would get very hot or
explode at somewhere between 95 and 100% of charge. I finally stopped
when I realized that while I could build the ultimate fast charger, it
could not be turned into a safe product for general consumption. Also,
a NiMH cell gets warm at any reasonable charge rate and would probably
be destroyed if accidentally inserted into my NiCd very fast charger.

Drivel: The energy density of a ham and cheese sandwich is higher
than that of dynamite. See bottom of table:
<https://en.wikipedia.org/wiki/Energy_density#Energy_densities_of_common_energy_storage_materials>
If you eat the sandwich too quickly, you might explode.

Phil Allison

unread,
Jun 23, 2017, 12:39:36 AM6/23/17
to
George Herold wrote:

---------------------


> >
> > > I'm not going to go to Batteries R Us and buy an Energizer just to
> > > test and post here.
> >
> > ** Then don't post at all.
>
>
> Nah, keep posting.
>

** Fuck off George.

The idiot is posting completed drivel - even worse than your crap.


..... Phil

John S

unread,
Jun 23, 2017, 4:24:46 PM6/23/17
to
You seem to be "riding the rag", Pill. Maybe you should go suck a cock
and relax for a while.

Jasen Betts

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Jun 23, 2017, 6:30:57 PM6/23/17
to
On 2017-06-21, John S <Sop...@invalid.org> wrote:
>
> I applied 2.47A to the probes from a linear lab supply. I measured the
> voltage at the probe tips and got .39V which gives .157 ohms. This is
> even more unreasonable than my resistance measurement. If it is even
> close to reality, I doubt that the 20A range would support even 10A for
> long.

if that includes the resistance of the leads, not all the heading will
be internal to the meter.

--
This email has not been checked by half-arsed antivirus software

Phil Allison

unread,
Jun 23, 2017, 7:48:47 PM6/23/17
to
John Shithead wrote:

--------------------


> >>>>
> >>>
> >>> ** The 20 amp shunt is gonna be 10 milliohms.
> >>>
> >>> Likely there is a fuse in series with not too good contacts
> >>> accounting for the unstable reading. The probes and leads are adding
> >>> way more.
> >>
> >> Probably. But how much of a short circuit will the OP be able to provide?
> >>
> >
> > ** Irrelevant.
> >
> >
> >
> >>> It is VERY clear to me you are NOT testing fresh 9V alkaline
> >>> batteries.
> >>>
> >>> If you test a fresh Energizer, it will read close to 10 amps.
> >>
> >> How fresh is fresh?
> >>
> >
> >
> > ** Less than 2 years old.
> >
> >
> >> I was only trying to provide info with what I had on
> >> hand.
> >
> >
> > ** But it was wrong.
> >
> >> I'm not going to go to Batteries R Us and buy an Energizer just to
> >> test and post here.
> >
> > ** Then don't post at all.
> >
> >
> >> You are welcome to do so. Please do. Your data would
> >> be well accepted, I'm sure.
> >>
> >
> >
> > ** Have you not read this thread at all ???
> >
> > Might be an idea to do so now.
> >
>
> >
>
> You seem to be "riding the rag",
>


** FFS Mr Shithead, you did NOT read my other posts in this thread.

Cos you rudely told me to do something that I *ALREADY HAD * !!!

It's never too late for YOU to grow up and act like an adult.



..... Phil

John S

unread,
Jun 24, 2017, 2:43:06 AM6/24/17
to
I read all your posts because I respect your knowledge. But you did not
post data. You posted your OPINIONs of data sheet interpretations. Show
your data and how you obtained it. That is what I did. You can't do that?

Phil Allison

unread,
Jun 24, 2017, 4:03:26 AM6/24/17
to
John Shithead wrote:

-------------------------
>
>
> >>>
> >>> ** Have you not read this thread at all ???
> >>>
> >>> Might be an idea to do so now.
> >>>
> >>
> >>>
> >>
> >> You seem to be "riding the rag",
> >>
> >
> >
> > ** FFS Mr Shithead, you did NOT read my other posts in this thread.
> >
> > Cos you rudely told me to do something that I *ALREADY HAD * !!!
> >
> > It's never too late for YOU to grow up and act like an adult.
> >
> >
> >
> >
>
> I read all your posts because I respect your knowledge. But you did not
> post data.
>


** Yes I did, I have *measured* Energiser alkaline 9V batts under short circuit conditions several times in the past. That is the only way to sure way to know.

I also posted TO YOU a *measurement* I did on June 20 with an Aldi house brand 9V batt.


> You posted your OPINIONs of data sheet interpretations.


** That is a wild, false assumption made by you.

And you are a colossal shithead.



..... Phil


upsid...@downunder.com

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Jun 24, 2017, 6:30:41 AM6/24/17
to
Why not simply build your own shunt resistor ?

Take a 9 V battery connector, solder a thick 10-20 cm long loop of say
1.5 mm² wire between the positive and negative terminal and use the
flimsy original wires to connect to a DMM.

Take an other connector and replace the flimsy wires with some thick
wires and connect it to a sturdy power supply. Set the short circuit
current to say 10 A and connect the two connectors together by
rotating them 180 degrees. Read the voltage on the DMM on the other
connector. Thus, the system can be calibrated.

Remove the power supply and its connector and set the DMM in
_peak_hold_ mode. Insert a real 9 V battery into the measurement
connector. Read the DMM voltage and apply calibration data to get the
current through the shunt.

For repeated measurements, adjust shunt wire length so that at 20 A,
the instrument shows 200mV ( or 20 mV or whatever the smallest full
scale range is). Thus, if in a real measurement the meter reads 73 mV,
the current is 7.3 A, which requires minimal mental calculations :-)

Using the same type of connector on the calibrating power supply will
also simulate realistic resistance between the battery connector and
the shunt connector.

upsid...@downunder.com

unread,
Jun 24, 2017, 6:44:12 AM6/24/17
to
On Wed, 21 Jun 2017 14:25:11 -0700 (PDT), Phil Allison
<palli...@gmail.com> wrote:

>John S wrote:
>
>-------------------
>>
>>
>> I applied 2.47A to the probes from a linear lab supply. I measured the
>> voltage at the probe tips and got .39V which gives .157 ohms. This is
>> even more unreasonable than my resistance measurement. If it is even
>> close to reality, I doubt that the 20A range would support even 10A for
>> long.
>>
>>
>
>** The 20 amp shunt is gonna be 10 milliohms.
>
>Likely there is a fuse in series with not too good contacts accounting for the unstable reading. The probes and leads are adding way more.

If the 20 A range can be directly selected from the multimeter range
switch, there are a lot of unpredictable resistances and possibly fuse
resistances.

However, if you have to move the positive test lead to a separate jack
labeled "20 A", there are probably only a fixed high current shunt
resistor and no fuse protection.

Phil Allison

unread,
Jun 24, 2017, 8:03:31 AM6/24/17
to
upsid...@downunder.com wrote:

-------------------------------------

>
>
> If the 20 A range can be directly selected from the multimeter range
> switch, there are a lot of unpredictable resistances and possibly fuse
> resistances.
>
>
> However, if you have to move the positive test lead to a separate jack
> labeled "20 A", there are probably only a fixed high current shunt
> resistor and no fuse protection.
>
>

** Wrong - because that is exactly where you are likely to find a *HRC* fuse fitted. Why ?????

To protect the probe leads for exploding and seriously injuring the user.

What does the user have to do to trigger such an event ??

Pick the wrong settings when probing high energy circuits - like 3 phase AC or a car battery.

Don't you know anything ?




..... Phil




upsid...@downunder.com

unread,
Jun 24, 2017, 10:36:29 AM6/24/17
to
It is possible that current multimeter safety standards require such a
fuse also on the high current settings. This has not always been the
case, e.g.
http://public.beuth-hochschule.de/hamann/MULTIMETER/mx202.html

In fact adding the "15 A range" to this instrument just required two
alligator clips and a short piece of thick test lead. 10 A flows
through the shunt and 5 A through the meter and you had a 15 A
instrument (there was a 1.5 scale in the meter) :-).

With any multimeter, it is very easy to make a mistake when using the
range and/or mode switch, thus as much as possible protection is
desirable.

However, in addition to changing the selector setting, if you also
have to change test lead position, you really have to think what you
are doing, so too much protection is not so desirable if this reduces
the functionality of the device.

Previously, it was quite easy to find multimeters with max 1000 V,
1500 V and even 2000 V (3 1/2 digits), but these days most are
restricted to 600 V. Does this have something to do with that the US
defines the limit between low voltage (LV) and medium/high (MV/HV) at
600 V,while the rest of the world (IEC) specifies it at 1000 Vac and
1500 Vdc ?

Phil Allison

unread,
Jun 24, 2017, 11:38:07 PM6/24/17
to
upsid...@downunder.com wrote:

-----------------------------------
>
> It is possible that current multimeter safety ...
>


** Post your meandering drivel elsewhere in future.

Cos it has SFA to do with anything I post.



..... Phil


Spehro Pefhany

unread,
Jun 25, 2017, 12:21:47 AM6/25/17
to
On Sat, 24 Jun 2017 17:36:25 +0300, the renowned
upsid...@downunder.com wrote:


>
>It is possible that current multimeter safety standards require such a
>fuse also on the high current settings. This has not always been the
>case, e.g.
>http://public.beuth-hochschule.de/hamann/MULTIMETER/mx202.html
>

Eg.

https://i.imgur.com/1tgiOaK.png

k...@notreal.com

unread,
Jun 25, 2017, 4:24:45 PM6/25/17
to
On Sun, 25 Jun 2017 00:21:45 -0400, Spehro Pefhany
<spef...@interlogDOTyou.knowwhat> wrote:

>On Sat, 24 Jun 2017 17:36:25 +0300, the renowned
>upsid...@downunder.com wrote:
>
>
>>
>>It is possible that current multimeter safety standards require such a
>>fuse also on the high current settings. This has not always been the
>>case, e.g.
>>http://public.beuth-hochschule.de/hamann/MULTIMETER/mx202.html
>>
>
>Eg.
>
>https://i.imgur.com/1tgiOaK.png

Fluke 77s and 88s are not fused, where Keysight's are. Perhaps it's
not a "standards" thing.

Phil Allison

unread,
Jun 25, 2017, 8:19:28 PM6/25/17
to
k...@notreal.com wrote:

------------------------------
>
> >https://i.imgur.com/1tgiOaK.png
>
> Fluke 77s and 88s are not fused, where Keysight's are. Perhaps it's
> not a "standards" thing.
>
>

** The Fluke 77 and 88 **DO** have fuse protection for the current ranges.

The one for the 10 amp range is a special HRC type rated to break 20kA.

http://www.fluke.com/fluke/auen/support/fuseguide/default.htm



.... Phil

k...@notreal.com

unread,
Jun 25, 2017, 9:27:49 PM6/25/17
to
http://toolmonger.com/2008/12/30/tm%E2%80%99s-2008-favorites-fluke-77-multimeter/

Apparently there are both out there. I can't find the picture I found
of more recent meters, so perhaps you're right (and I was dreaming).

Publi...@aol.com

unread,
Nov 5, 2017, 12:24:42 AM11/5/17
to
I happen to be looking for info in this subject as well. I am trying to find out how many amps I can draw off a typical 9v household batter for 1 to 3 milliseconds. I know it is the worst choice I could have made in my design, but I was restricted in size. I have decided not to use alkaline. That leaves me with non rechargeable lithiums or rechargeable nicads or Nimh. I am leaning towards the nicads. I am using a IRLZ44 as my MOSFET if that matters any. The project is a Lazer Tag toy that I have modified to for 36 IR LEDs in four banks of 9 LEDs each. The LEDs in each bank are in parallel. I have 2 9v in series so i can tap of 9 volts of the toy and 18v to get all those LEDs to turn on. It has been an improvement of the stock toy, but not by much. So I am going to use some new IR LED that put out my IR with less amps and I most likely have to reduce the amount of LEDs as well. So just looking for an opinion on the very limited choices I have. Not enough room to use any other type of battery. A redesign is out of the question for now.

I am not very knowledgeable about this sort of stuff, but I have some good people to turn to.

I am grateful for any help you can off. Yes I know I am going to get flamed a bit but I am not a snowflake.

Thanks
John

mike

unread,
Nov 5, 2017, 12:30:55 AM11/5/17
to
Isn't that what capacitors do very well?

Publi...@aol.com

unread,
Nov 5, 2017, 12:41:50 AM11/5/17
to
Why yes they do.. but they do little good if you did not include them in the design and no there is no room. But with that said, what do you recommend?

Publi...@aol.com

unread,
Nov 5, 2017, 1:58:59 AM11/5/17
to
Now silly me....I did not see that LIPOs have gotten really really small. Time to get away from 1990 level of knowledge

mike

unread,
Nov 5, 2017, 3:44:09 AM11/5/17
to
I don't know how you got past the design "point of no return" without
considering the power supply. My recommendation is a redesign.
I don't have nearly enough info to recommend anything particular,
but you're asking for reliability problems and unhappy customers.
If a device takes standard 9V batteries, it should work reliably
with any randomly acquired commercial 9V battery.
Customers don't care that you goofed. They care whether the device
does what it's intended to do.

kevin93

unread,
Nov 5, 2017, 7:22:41 AM11/5/17
to
On Tuesday, June 20, 2017 at 7:27:43 AM UTC-7, George Herold wrote:
...
> > I set my DVM on the 20A range and probed the terminals. I got 2.54A.
> >
> > John S
>
> Any idea what the input impedance of the DMM is? (It most likely
> has a big ass-fuse* in series.)
...

Many lower cost meters only have a fuse of a few hundred milliamps on the lower current ranges with no fuse on the high-current ones so incorrect usage can damage the shunt.

My Fluke 189 does have both a low current (440mA) and high-current (11A) fuse. They are "big ass-fuses" but that is mainly because they are rated at 1000V. They are about 30mm long by 7mm diameter filled with sand.

Typically DMMs have a basic voltage scale of 200mV which sets the burden on the current ranges. Be careful of the drop on the leads though as that can add as much again for high currents.

kevin

TTman

unread,
Nov 5, 2017, 7:31:33 AM11/5/17
to
Nice... Laser Tag is my favourite subject. Can't you use a suitable 4/5
cell Lipo ? Check out Actual Reality Laser from the 90's..


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Publi...@aol.com

unread,
Nov 5, 2017, 11:13:16 AM11/5/17
to
You are right on all points. I got to the point of no return because I do not know what I am doing and lots of glue The customers is myself. Yes it needs a redesign... big time. It was a learning project and I did some rather clever things with it. But I had not researched new types of batteries and just went with what I knew....and that is not much. I am just a hobby guy. Anyway. Thank you for your input. It does help. Reading this thread and looking at a few other web sights has made it pretty clear to me there is no real way to fix this. I can tweak it some and get a little more out of it.

Thanks again

Publi...@aol.com

unread,
Nov 5, 2017, 11:34:38 AM11/5/17
to
Hi TTman
> >
> Nice... Laser Tag is my favourite subject. Can't you use a suitable 4/5
> cell Lipo ? Check out Actual Reality Laser from the 90's..
>
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> https://www.avast.com/antivirus

These guys ? http://www.lasertagmuseum.com/indoor-laser-tag/indoor-company/a-f/actual-reality

I sold some rare WoW lazer tag to Eric there at the Museum. I hope to go there someday.
Yes I am looking into the lipo option now. Here is what I have right now http://www.bgmicro.com/LED1058.aspx

And I used 36 Vishay TSOP6100 IR LEDs. Until I can make a new one I am going to have to tweak what I can. I can remove the array and replace the IR LEDS with a new line from Vishay VSLY5940. It is not only more powerful, it is also a much tighter half angle along with needing less power to drive them all. I can also cut down on how many I need.

What the toy is( and you can find it on the museum page) is the Hasbro/Tiger/Nerf LTX. I have the shotblast attachment that is like a pump action shotgun for close range wide spread damage. It is unlimited in ammo and use on a game. What I did was to modify one to work for only 5 shots.. but damn those 5 shots were going to be a world of hurt for other players. It is an improvement, but not at all what I hoped for. I knew from the start that power was going to be an issue. I just did not know how underwhelming it was until I got it out in the field. Here is really the only testing of what I did. https://youtu.be/JF-UvXGGdMs

mike

unread,
Nov 5, 2017, 2:32:32 PM11/5/17
to
I know zero about laser tag, but...
My first question would be, "What happens when you fire it into
someone's eye at close range?"

Yes, you know all about eye protection and safety features and and and
you'd never do anything unsafe...

I'm sure the guy blinded in the locker room will be impressed by your
choice of battery.

This might be instructive:
https://www.merriam-webster.com/dictionary/accident

k...@notreal.com

unread,
Nov 5, 2017, 6:35:46 PM11/5/17
to
On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:

>On 11/5/2017 8:34 AM, Publi...@aol.com wrote:
>> Hi TTman
>>>>
>>> Nice... Laser Tag is my favourite subject. Can't you use a suitable 4/5
>>> cell Lipo ? Check out Actual Reality Laser from the 90's..
>>>
>>>
>>> ---
>>> This email has been checked for viruses by Avast antivirus software.
>>> https://www.avast.com/antivirus
>>
>> These guys ? http://www.lasertagmuseum.com/indoor-laser-tag/indoor-company/a-f/actual-reality
>>
>> I sold some rare WoW lazer tag to Eric there at the Museum. I hope to go there someday.
>> Yes I am looking into the lipo option now. Here is what I have right now http://www.bgmicro.com/LED1058.aspx
>>
>> And I used 36 Vishay TSOP6100 IR LEDs. Until I can make a new one I am going to have to tweak what I can. I can remove the array and replace the IR LEDS with a new line from Vishay VSLY5940. It is not only more powerful, it is also a much tighter half angle along with needing less power to drive them all. I can also cut down on how many I need.
>>
>> What the toy is( and you can find it on the museum page) is the Hasbro/Tiger/Nerf LTX. I have the shotblast attachment that is like a pump action shotgun for close range wide spread damage. It is unlimited in ammo and use on a game. What I did was to modify one to work for only 5 shots.. but damn those 5 shots were going to be a world of hurt for other players. It is an improvement, but not at all what I hoped for. I knew from the start that power was going to be an issue. I just did not know how underwhelming it was until I got it out in the field. Here is really the only testing of what I did. https://youtu.be/JF-UvXGGdMs
>>
>I know zero about laser tag, but...
>My first question would be, "What happens when you fire it into
>someone's eye at close range?"

Does range matter much? (it's a "LASER") You could PWM it to a safe
power level.

mike

unread,
Nov 5, 2017, 6:46:27 PM11/5/17
to
On 11/5/2017 3:35 PM, k...@notreal.com wrote:
> On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:

>> I know zero about laser tag, but...
>> My first question would be, "What happens when you fire it into
>> someone's eye at close range?"
>
> Does range matter much? (it's a "LASER") You could PWM it to a safe
> power level.
>>
Well, that's the question.
At a safe power level, you would have no reason to build it.
And it wouldn't need a super battery either.
As for range, I'd reason that close range would cause greater
destruction. Angular movement of the beam at long range would
result is shorter exposure time on individual portions of the retina.

k...@notreal.com

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Nov 5, 2017, 6:50:14 PM11/5/17
to
On Sun, 05 Nov 2017 15:45:13 -0800, mike <ham...@netzero.net> wrote:

>On 11/5/2017 3:35 PM, k...@notreal.com wrote:
>> On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:
>
>>> I know zero about laser tag, but...
>>> My first question would be, "What happens when you fire it into
>>> someone's eye at close range?"
>>
>> Does range matter much? (it's a "LASER") You could PWM it to a safe
>> power level.
>>>
>Well, that's the question.
>At a safe power level, you would have no reason to build it.

Huh? He's not trying to kill anyone. Just detect a hit.

>And it wouldn't need a super battery either.

He has to drive the laser.

>As for range, I'd reason that close range would cause greater
>destruction. Angular movement of the beam at long range would
>result is shorter exposure time on individual portions of the retina.

So you'd count on movement to save eyes? <sheesh>

mike

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Nov 5, 2017, 8:04:24 PM11/5/17
to
On 11/5/2017 3:50 PM, k...@notreal.com wrote:
> On Sun, 05 Nov 2017 15:45:13 -0800, mike <ham...@netzero.net> wrote:
>
>> On 11/5/2017 3:35 PM, k...@notreal.com wrote:
>>> On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:
>>
>>>> I know zero about laser tag, but...
>>>> My first question would be, "What happens when you fire it into
>>>> someone's eye at close range?"
>>>
>>> Does range matter much? (it's a "LASER") You could PWM it to a safe
>>> power level.
>>>>
>> Well, that's the question.
>> At a safe power level, you would have no reason to build it.
>
> Huh? He's not trying to kill anyone. Just detect a hit.
No, he's trying to increase power and spread.
I'm concerned that both pose a safety hazard to others.
>
>> And it wouldn't need a super battery either.
>
> He has to drive the laser.
>
>> As for range, I'd reason that close range would cause greater
>> destruction. Angular movement of the beam at long range would
>> result is shorter exposure time on individual portions of the retina.
>
> So you'd count on movement to save eyes? <sheesh>
>
You seem to be going out of your way to misinterpret and disagree.
I count on power reduction to save eyes.
My comment was in response to your statement implying that range doesn't
matter. I believe that close is worse than far away, although neither
may be safe.

Laser tag is about skill. You AIM, you shoot...the best man wins.
The proposed project sounds more like a nuclear strike.
Fire and anybody within range dies. Where's the skill in that?

k...@notreal.com

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Nov 5, 2017, 8:07:45 PM11/5/17
to
On Sun, 05 Nov 2017 17:03:10 -0800, mike <ham...@netzero.net> wrote:

>On 11/5/2017 3:50 PM, k...@notreal.com wrote:
>> On Sun, 05 Nov 2017 15:45:13 -0800, mike <ham...@netzero.net> wrote:
>>
>>> On 11/5/2017 3:35 PM, k...@notreal.com wrote:
>>>> On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:
>>>
>>>>> I know zero about laser tag, but...
>>>>> My first question would be, "What happens when you fire it into
>>>>> someone's eye at close range?"
>>>>
>>>> Does range matter much? (it's a "LASER") You could PWM it to a safe
>>>> power level.
>>>>>
>>> Well, that's the question.
>>> At a safe power level, you would have no reason to build it.
>>
>> Huh? He's not trying to kill anyone. Just detect a hit.
>No, he's trying to increase power and spread.
>I'm concerned that both pose a safety hazard to others.

Spread does just the opposite. There is a difference between peak
power and average power. Eyes don't care about peak power.
>>
>>> And it wouldn't need a super battery either.
>>
>> He has to drive the laser.
>>
>>> As for range, I'd reason that close range would cause greater
>>> destruction. Angular movement of the beam at long range would
>>> result is shorter exposure time on individual portions of the retina.
>>
>> So you'd count on movement to save eyes? <sheesh>
>>
>You seem to be going out of your way to misinterpret and disagree.
>I count on power reduction to save eyes.
>My comment was in response to your statement implying that range doesn't
>matter. I believe that close is worse than far away, although neither
>may be safe.
>
>Laser tag is about skill. You AIM, you shoot...the best man wins.
>The proposed project sounds more like a nuclear strike.
>Fire and anybody within range dies. Where's the skill in that?

The electronics, since that's why he's here.

mike

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Nov 5, 2017, 8:43:19 PM11/5/17
to
On 11/5/2017 5:07 PM, k...@notreal.com wrote:
> On Sun, 05 Nov 2017 17:03:10 -0800, mike <ham...@netzero.net> wrote:
>
>> On 11/5/2017 3:50 PM, k...@notreal.com wrote:
>>> On Sun, 05 Nov 2017 15:45:13 -0800, mike <ham...@netzero.net> wrote:
>>>
>>>> On 11/5/2017 3:35 PM, k...@notreal.com wrote:
>>>>> On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:
>>>>
>>>>>> I know zero about laser tag, but...
>>>>>> My first question would be, "What happens when you fire it into
>>>>>> someone's eye at close range?"
>>>>>
>>>>> Does range matter much? (it's a "LASER") You could PWM it to a safe
>>>>> power level.
>>>>>>
>>>> Well, that's the question.
>>>> At a safe power level, you would have no reason to build it.
>>>
>>> Huh? He's not trying to kill anyone. Just detect a hit.
>> No, he's trying to increase power and spread.
>> I'm concerned that both pose a safety hazard to others.
>
> Spread does just the opposite. There is a difference between peak
> power and average power. Eyes don't care about peak power.

Drop by and we'll test that theory on your eye.

k...@notreal.com

unread,
Nov 5, 2017, 9:00:35 PM11/5/17
to
On Sun, 05 Nov 2017 17:42:06 -0800, mike <ham...@netzero.net> wrote:

>On 11/5/2017 5:07 PM, k...@notreal.com wrote:
>> On Sun, 05 Nov 2017 17:03:10 -0800, mike <ham...@netzero.net> wrote:
>>
>>> On 11/5/2017 3:50 PM, k...@notreal.com wrote:
>>>> On Sun, 05 Nov 2017 15:45:13 -0800, mike <ham...@netzero.net> wrote:
>>>>
>>>>> On 11/5/2017 3:35 PM, k...@notreal.com wrote:
>>>>>> On Sun, 05 Nov 2017 11:31:16 -0800, mike <ham...@netzero.net> wrote:
>>>>>
>>>>>>> I know zero about laser tag, but...
>>>>>>> My first question would be, "What happens when you fire it into
>>>>>>> someone's eye at close range?"
>>>>>>
>>>>>> Does range matter much? (it's a "LASER") You could PWM it to a safe
>>>>>> power level.
>>>>>>>
>>>>> Well, that's the question.
>>>>> At a safe power level, you would have no reason to build it.
>>>>
>>>> Huh? He's not trying to kill anyone. Just detect a hit.
>>> No, he's trying to increase power and spread.
>>> I'm concerned that both pose a safety hazard to others.
>>
>> Spread does just the opposite. There is a difference between peak
>> power and average power. Eyes don't care about peak power.
>
>Drop by and we'll test that theory on your eye.

It's a fact, idiot. It's heating that burns tissue, not some mystical
"LASER" power. You watch too much television.

Publi...@aol.com

unread,
Nov 5, 2017, 10:16:37 PM11/5/17
to
Hey Mike.. Not sure what I did to piss you off. Sorry if I offended you. Yeah I had the same concerns. So I went to a friend of mine that designed the gear we use. 100% safe. The duration and lack of lens to focus that energy make it a non issues. I play with people i have been friends with for decades. Do you really think I would want to blind them? Come on man.. why so cynical? Instead of the insult approach could you just asked what I have done to address eye safety.. so seeing how you cannot help here... just tap out.
> >a

Publi...@aol.com

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Nov 5, 2017, 10:18:57 PM11/5/17
to
It is NOT a laser.. this is laZER tag. The word has no meaning. It uses common IR LEDs

Publi...@aol.com

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Nov 5, 2017, 10:25:14 PM11/5/17
to
Again.. no real lasers used. This is a kids toy. Do you really think Hasbro would install real laser in toys?

Publi...@aol.com

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Nov 5, 2017, 10:28:45 PM11/5/17
to
The skill is that it is not made for regular type games. I also tried my best to balance it out with limiting it shot to 5.. compared to unlimited with the stock gear

Publi...@aol.com

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Nov 5, 2017, 10:46:18 PM11/5/17
to
OK please everyone PLEASE stop tearing into each other. Really I get every ones concern about lasers and what you thought I was going to do with them. This is NOT the laser tag gear used in arenas. It is a toy sold to kids. No real lasers used. And I will NEVER touch or try to install a real laser because I WOULD end up hurting someone. There is SOME concern about high output IR LEDs but this is not an issues with how this is being used. The shot duration is too short and it is not focused with a lens. Even with a lens it is still safe.

I have been at this hobby for 30 years. I have met and have become friends with the designers of this gear. I know someone that really does work with lasers. Repairs MILES gear for the US ARMY. I know enough to now to ask those who do know.


So just to be clear... TOY... no real lasers.... called Lazer Tag... note the z. Now can we take a step back and be nice?

Thanks
John

Jasen Betts

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Nov 6, 2017, 1:01:25 AM11/6/17
to
On 2017-11-05, mike <ham...@netzero.net> wrote:
> On 11/5/2017 8:34 AM, Publi...@aol.com wrote:
>> Hi TTman
>>>>
>>> Nice... Laser Tag is my favourite subject. Can't you use a suitable 4/5
>>> cell Lipo ? Check out Actual Reality Laser from the 90's..
>>>
>>>
>>> ---
>>> This email has been checked for viruses by Avast antivirus software.
>>> https://www.avast.com/antivirus
>>
>> These guys ? http://www.lasertagmuseum.com/indoor-laser-tag/indoor-company/a-f/actual-reality
>>
>> I sold some rare WoW lazer tag to Eric there at the Museum. I hope to go there someday.
>> Yes I am looking into the lipo option now. Here is what I have right now http://www.bgmicro.com/LED1058.aspx
>>
>> And I used 36 Vishay TSOP6100 IR LEDs. Until I can make a new one I am going to have to tweak what I can. I can remove the array and replace the IR LEDS with a new line from Vishay VSLY5940. It is not only more powerful, it is also a much tighter half angle along with needing less power to drive them all. I can also cut down on how many I need.
>>
>> What the toy is( and you can find it on the museum page) is the Hasbro/Tiger/Nerf LTX. I have the shotblast attachment that is like a pump action shotgun for close range wide spread damage. It is unlimited in ammo and use on a game. What I did was to modify one to work for only 5 shots.. but damn those 5 shots were going to be a world of hurt for other players. It is an improvement, but not at all what I hoped for. I knew from the start that power was going to be an issue. I just did not know how underwhelming it was until I got it out in the field. Here is really the only testing of what I did. https://youtu.be/JF-UvXGGdMs

> I know zero about laser tag, but...
> My first question would be, "What happens when you fire it into
> someone's eye at close range?"

Laser tag uses focused infared beams (not lasers, just regular
ifrared LEDs) to activate infared sensitive targets, some of the
guns also blink a low power visible laser as a guide to help the
shooter aim.

The beam exits the gun with a diameter about 20mm, so even at
close range you can only get a small fraction of the power throug
the pupil.

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