My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

On 08/11/2020 13:42, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.


It's probably only calibrated for the former but by putting a resistive
load across the battery during the test will bring the voltage below
1.2V on a bad battery.

--
mailto : news {at} admac {dot} myzen {dot} co {dot} uk

On 08/11/2020 13:42:21, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

Internal resistance is a good indication of battery capacity, and the
easiest way to measure this is under load.

On Sun, 08 Nov 2020 13:42:21 +0000, Scott wrote:

My multimeter has a battery test facility that shows the battery as good
or bad (or on the margin). I understand a zinc carbon battery has a
voltage of 1.5 Volts and an alkaline battery has a voltage of 1.2 Volts?
How does it know the difference between a very good alkaline battery
and a very bad zinc carbon battery?.

Alkaline are also 1.5v. You are thinking of rechargeables (e.h. NiMH) for
1.2v.



--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

That is clearly not so, since most of them have 1.5v, its only rechargeable
nicad or nimh that have 1.2v.

The normal way I test batteries is with a load, If you blip a reasonable
load on a good battery, no change in volts, on a partly dead one there is a
drop, as the area used is smaller, ie it cannot shove out the same current
as its electrodes get coated. Most alkaline if used a little, charged a
little etc can last a surprisingly long time before the system cannot hold
the charge. Beware though as the seals can go with the pressure inside if
you get too greedy.
Brian

--
Brian Gaff -

Blind user, so no pictures please!

This document should only be read by those persons for whom Paranoia is
normal
and its contents are probably boring and confusing. If you receive this
e-Mail
message in error, do not notify the sender immediately, instead, print it
out and make
paper animals out of it. As the rest of this disclaimer is totally
incomprehensible, we have not bothered to attach it.
"Scott" wrote in message
...
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

On 8 Nov 2020 14:05:40 GMT, Bob Eager wrote:

On Sun, 08 Nov 2020 13:42:21 +0000, Scott wrote:

My multimeter has a battery test facility that shows the battery as good
or bad (or on the margin). I understand a zinc carbon battery has a
voltage of 1.5 Volts and an alkaline battery has a voltage of 1.2 Volts?
How does it know the difference between a very good alkaline battery
and a very bad zinc carbon battery?.

Alkaline are also 1.5v. You are thinking of rechargeables (e.h. NiMH) for
1.2v.

Thanks. This certainly explains it. I was indeed mistaken.

Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

Alkaline are also 1.5v when new.

It's rechargeable NiCd and NiMh that have a lower 'good' voltage,
around 1.2 to 1.3 volts.

--
Chris Green
·

On Sun, 8 Nov 2020 16:43:54 +0000, Chris Green wrote:

Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

Alkaline are also 1.5v when new.

It's rechargeable NiCd and NiMh that have a lower 'good' voltage,
around 1.2 to 1.3 volts.

Indeed, mea culpa.

On Sunday, November 8, 2020 at 7:52:41 AM UTC-6, alan_m wrote:
On 08/11/2020 13:42, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.


It's probably only calibrated for the former but by putting a resistive
load across the battery during the test will bring the voltage below
1.2V on a bad battery.

--


interesting. I saw this a couple places earlier today too.

mk5000

Today, while the blossoms still cling to the vine
I'll taste your strawberries, I'll drink your sweet wine
A million tomorrows shall all pass away
'Ere I forget all the joy that is mine...today


https://www.letssingit.com/the-new-c...-today-gwpvc48

On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.


NT

wrote:
On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.


NT

https://learn.sparkfun.com/tutorials...nal-resistance

"We can only take a snapshot of the internal resistance
with this method. The internal resistance can vary with things
like battery age and temperature. In 10 minutes, the resistance
value might be different!

A common AA alkaline battery might have anywhere between
0.1 Ω and 0.9 Ω internal resistance."

https://data.energizer.com/PDFs/BatteryIR.pdf

"The typical effective resistances of fresh
Energizer alkaline cylindrical batteries (using a 5
mA stabilization drain followed by a 505 mA 100
millisecond pulse) will be approximately 150 to
300 milliohms, depending on size."

The Energizer method uses two load resistors, first
tests with the light load, then light+heavy load.

Paul

On 08/11/2020 23:25, wrote:
On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.


NT


I used to love winding up car boot sellers, flogging batteries.
I would ask them for SR44 camera batteries, and they would always
try and flog me LR44's, "because they are the same".

When asked what their understanding of current delivery characteristics
is, they would get into the usual nonsense claim that they "would work",
which in many cases they wouldn't.

On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin).Â* I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts?Â* How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

Internal resistance is a good indication of battery capacity, and the
easiest way to measure this is under load.

Most battery testers are based on presenting a load to the cell and then
measuring the voltage under that stress test. Some Duracells had a self
test feature at one time - but it made them much less reliable

I no longer use Duracells I have had too many leaks. Panasonic and
Energiser are my preferred brands now for things where rechargeables
won't hack it. Usually low current draw LCD display devices.

--
Regards,
Martin Brown

On Sun, 8 Nov 2020 15:25:37 -0800 (PST), wrote:

On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.

Could my battery testing facility (in the multimeter) be doing this?

On 09/11/2020 10:19, Scott wrote:
On Sun, 8 Nov 2020 15:25:37 -0800 (PST), wrote:

On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.

Given that a humble AA can source 10A into a dead short that would quite
likely wrap the needle round the end stop on an analogue meter or blow
the internal fuse on a modern digital meter.

Could my battery testing facility (in the multimeter) be doing this?

It probably measures the battery terminal voltage with and without a
suitable load resistor across it.

--
Regards,
Martin Brown

On 09/11/2020 11:31:07, Martin Brown wrote:
On 09/11/2020 10:19, Scott wrote:
On Sun, 8 Nov 2020 15:25:37 -0800 (PST), wrote:

On Sunday, 8 November 2020 13:42:26 UTC, ScottÂ* wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin).Â* I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts?Â* How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current.
Terminal voltage often tells enough, but not always. The other test
is to touch probes of a 1A meter to the battery for a fraction of a
second, see how fast the needle flies up. Digital meters generally
can't do this. Keep the probes on & you'll kill both meter & battery.

Given that a humble AA can source 10A into a dead short that would quite
likely wrap the needle round the end stop on an analogue meter or blow
the internal fuse on a modern digital meter.

I have a cheapo meter that can handle 20A. Combined with the resistance
of the test leads I think it would be quite safe for the meter. The
leads might get warm though!

On 09/11/2020 10:19:02, Scott wrote:
On Sun, 8 Nov 2020 15:25:37 -0800 (PST), wrote:

On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.

Could my battery testing facility (in the multimeter) be doing this?

It might but you need to look at the instructions/spec of your meter to
confirm.

I don't have a meter with this facility, nor have I seen a multimeter
that has.

In article ,
wrote:
There are 2 requirements for a good battery: voltage & current. Terminal
voltage often tells enough, but not always. The other test is to touch
probes of a 1A meter to the battery for a fraction of a second, see how
fast the needle flies up. Digital meters generally can't do this. Keep
the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed the
current range.

--
*Income tax service - We‘ve got what it takes to take what you've got.

Dave Plowman London SW
To e-mail, change noise into sound.

On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin).Â* I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts?Â* How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had a couple do that earlier this year. They were well used then recharged, and gave a strangely high output. No idea why, none of the others did.


NT

On Monday, 9 November 2020 11:31:11 UTC, Martin Brown wrote:
On 09/11/2020 10:19, Scott wrote:
On Sun, 8 Nov 2020 15:25:37 -0800 (PST), tabbypurr wrote:
On Sunday, 8 November 2020 13:42:26 UTC, Scott wrote:

My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin). I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts? How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current. Terminal voltage often tells enough, but not always. The other test is to touch probes of a 1A meter to the battery for a fraction of a second, see how fast the needle flies up. Digital meters generally can't do this. Keep the probes on & you'll kill both meter & battery.

Given that a humble AA can source 10A into a dead short that would quite
likely wrap the needle round the end stop on an analogue meter or blow
the internal fuse on a modern digital meter.

that's why it's only connected for a fraction of a second. What you're looking for is enough oomph to be confident the needle would fly off the end if it stayed connected. Harmless if not sustained.
You can't use the method with digitals.


Could my battery testing facility (in the multimeter) be doing this?

It probably measures the battery terminal voltage with and without a
suitable load resistor across it.

A load resistor yes, how suitable is another matter. They tend to load them very lightly.


NT

On Monday, 9 November 2020 13:05:27 UTC, Fredxx wrote:
On 09/11/2020 11:31:07, Martin Brown wrote:
On 09/11/2020 10:19, Scott wrote:
On Sun, 8 Nov 2020 15:25:37 -0800 (PST), tabbypurr wrote:

On Sunday, 8 November 2020 13:42:26 UTC, ScottÂ* wrote:
My multimeter has a battery test facility that shows the battery as
good or bad (or on the margin).Â* I understand a zinc carbon battery
has a voltage of 1.5 Volts and an alkaline battery has a voltage of
1.2 Volts?Â* How does it know the difference between a very good
alkaline battery and a very bad zinc carbon battery?.

There are 2 requirements for a good battery: voltage & current.
Terminal voltage often tells enough, but not always. The other test
is to touch probes of a 1A meter to the battery for a fraction of a
second, see how fast the needle flies up. Digital meters generally
can't do this. Keep the probes on & you'll kill both meter & battery.

Given that a humble AA can source 10A into a dead short that would quite
likely wrap the needle round the end stop on an analogue meter or blow
the internal fuse on a modern digital meter.

I have a cheapo meter that can handle 20A. Combined with the resistance
of the test leads I think it would be quite safe for the meter. The
leads might get warm though!

If anything gets warm you left it connected way too long.

On Monday, 9 November 2020 13:51:59 UTC, Dave Plowman (News) wrote:
In article ,
tabbypurr wrote:
There are 2 requirements for a good battery: voltage & current. Terminal
voltage often tells enough, but not always. The other test is to touch
probes of a 1A meter to the battery for a fraction of a second, see how
fast the needle flies up. Digital meters generally can't do this. Keep
the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed the
current range.

Nah, fuses require a fair bit of i squared t. Anyway if someone does this with a digital they clearly don't know what they're doing.


NT

On 10/11/2020 03:04:36, wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:
My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

The only odd circumstance I can think of will be a duff meter.

On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel free to get stupid again.


NT

In article ,
wrote:
On Monday, 9 November 2020 13:51:59 UTC, Dave Plowman (News) wrote:
In article ,
tabbypurr wrote:
There are 2 requirements for a good battery: voltage & current.
Terminal voltage often tells enough, but not always. The other test
is to touch probes of a 1A meter to the battery for a fraction of a
second, see how fast the needle flies up. Digital meters generally
can't do this. Keep the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed
the current range.

Nah, fuses require a fair bit of i squared t. Anyway if someone does
this with a digital they clearly don't know what they're doing.


But it's you that said it will kill the DVM...

--
*After the game, the King and the pawn go into the same box.

Dave Plowman London SW
To e-mail, change noise into sound.

On 11/11/2020 03:13:29, wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.

I have and 1.65 is the highest I saw for a new battery. An old battery
will typically be 1V.

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel free to get stupid again.

Perhaps it was user error then, or not recognising a malfunctioning meter?

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.

On 11/11/2020 10:54:21, Dave Plowman (News) wrote:
In article ,
wrote:
On Monday, 9 November 2020 13:51:59 UTC, Dave Plowman (News) wrote:
In article ,
tabbypurr wrote:
There are 2 requirements for a good battery: voltage & current.
Terminal voltage often tells enough, but not always. The other test
is to touch probes of a 1A meter to the battery for a fraction of a
second, see how fast the needle flies up. Digital meters generally
can't do this. Keep the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed
the current range.

Nah, fuses require a fair bit of i squared t. Anyway if someone does
this with a digital they clearly don't know what they're doing.


But it's you that said it will kill the DVM...


I see some consistency here, where the facts are bent to meet opinion.

Fredxx wrote:
On 11/11/2020 03:13:29, wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.

I have and 1.65 is the highest I saw for a new battery. An old battery
will typically be 1V.

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel
free to get stupid again.

Perhaps it was user error then, or not recognising a malfunctioning meter?

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.

Have we no electrochemists in the house ?

https://michaelbluejay.com/batteries/rechargeable.html

"NiZn's have the highest initial voltage of any rechargeable AA or
AAA battery. The nominal voltage is 1.65, and fresh out of the
charger the voltage is as high as 1.85V."

https://en.wikipedia.org/wiki/Nickel...93zinc_battery

(ˆ’) electrode:€ƒ Zn + 4 OHˆ’ ‡Œ Zn(OH)42ˆ’ + 2eˆ’ (E0 = ˆ’1.2 V/SHE )

(+) electrode:€ƒ 2 NiO(OH) + 2 H2O + 2 eˆ’ ‡Œ 2 Ni(OH)2 + 2 OHˆ’ (E0 = +0.50 V/SHE)

It's a redox reaction with two half-cell potentials, that give
the overall battery cell output voltage.

Was this battery mixed in with a lot of other batteries ?

Or did some other battery type leak, electrolyte got
between the inner cell metal jacket and the outer shell
steel covering ? The multimeter would need to be touching
the outer steel covering, instead of the tab on the
end, to (somehow) tap into the phantom voltage.

It makes more sense that it was a purpose-built NiZn cell.

Paul

In message , "Dave Plowman (News)"
writes
In article ,
wrote:
There are 2 requirements for a good battery: voltage & current. Terminal
voltage often tells enough, but not always. The other test is to touch
probes of a 1A meter to the battery for a fraction of a second, see how
fast the needle flies up. Digital meters generally can't do this. Keep
the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed the
current range.

And if the fuse is a 'special' (like in my Fluke) it's rather expensive.
[I think mine cost eight pounds.]
--
Ian

On 12/11/2020 00:55, Paul wrote:
Fredxx wrote:
On 11/11/2020 03:13:29, wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, FredxxÂ* wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin BrownÂ* wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin).Â* I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts?Â* How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.

I have and 1.65 is the highest I saw for a new battery. An old battery
will typically be 1V.

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel
free to get stupid again.

Perhaps it was user error then, or not recognising a malfunctioning
meter?

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.

Have we no electrochemists in the house ?

https://michaelbluejay.com/batteries/rechargeable.html

Â*Â* "NiZn's have the highest initial voltage of any rechargeable AA or
Â*Â*Â* AAA battery.Â* The nominal voltage is 1.65, and fresh out of the
Â*Â*Â* charger the voltage is as high as 1.85V."

https://en.wikipedia.org/wiki/Nickel...93zinc_battery

Â* (ˆ’) electrode:€ƒ Zn + 4 OHˆ’ ‡Œ Zn(OH)42ˆ’ + 2eˆ’ (E0 = ˆ’1.2 V/SHE )

Â* (+) electrode:€ƒ 2 NiO(OH) + 2 H2O + 2 eˆ’ ‡Œ 2 Ni(OH)2 + 2 OHˆ’ (E0 =
+0.50 V/SHE)

It's a redox reaction with two half-cell potentials, that give
the overall battery cell output voltage.

Was this battery mixed in with a lot of other batteries ?

Well spotted!

The 1.8v muppet was talking about *rechargeable* alkaline batteries when
everyone else was discussing single use primary alkaline AA batteries.

https://en.wikipedia.org/wiki/Alkaline_battery#Voltage

You can briefly see higher terminal voltages for a rechargeable battery
still under charge or very recently taken off a fast charger.

I have never seen a battery whose voltage increased significantly with
use as its remaining capacity decreased. YMMV
(but I expect that it doesn't)

--
Regards,
Martin Brown

Martin Brown wrote:

I have never seen a battery whose voltage increased significantly with
use as its remaining capacity decreased. YMMV
(but I expect that it doesn't)

Rechargeables can increase their voltage when discharging, I have a
discharge tester that shows voltage, current and capacity as it runs
and you often see a (small) increase in voltage at the beginning of
the discharge cycle.

--
Chris Green
·

In message , Chris Green
writes
Martin Brown wrote:

I have never seen a battery whose voltage increased significantly with
use as its remaining capacity decreased. YMMV
(but I expect that it doesn't)

Rechargeables can increase their voltage when discharging, I have a
discharge tester that shows voltage, current and capacity as it runs
and you often see a (small) increase in voltage at the beginning of
the discharge cycle.

If this happens, why? If has cooled down after charging, possibly the
effect of warming up a little?
--
Ian

On 12/11/2020 13:57:38, Ian Jackson wrote:
In message , Chris Green
writes
Martin Brown wrote:

I have never seen a battery whose voltage increased significantly with
use as its remaining capacity decreased. YMMV
(but I expect that it doesn't)

Rechargeables can increase their voltage when discharging, I have a
discharge tester that shows voltage, current and capacity as it runs
and you often see a (small) increase in voltage at the beginning of
the discharge cycle.

If this happens, why? If has cooled down after charging, possibly the
effect of warming up a little?

The reduced voltage is a consequence of temperature increase and the
corresponding reduction of terminal voltage. It is often used to
determine the charge end point.

https://batteryuniversity.com/learn/...ased_batteries

I can only assume the increase you're seeing is from the battery cooling
down in the initial discharge?

On 12/11/2020 08:31:14, Ian Jackson wrote:
In message , "Dave Plowman (News)"
writes
In article ,
Â* wrote:
There are 2 requirements for a good battery: voltage & current. Terminal
voltage often tells enough, but not always. The other test is to touch
probes of a 1A meter to the battery for a fraction of a second, see how
fast the needle flies up. Digital meters generally can't do this. Keep
the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed the
current range.

And if the fuse is a 'special' (like in my Fluke) it's rather expensive.
[I think mine cost eight pounds.]

Oh dear, did you find out the hard way?

I suspect the reason is the voltage rating of the fuse and arc suppression.

This can happen if you don't:

https://assets.publishing.service.go...LeHavre_98.pdf

On Thu, 12 Nov 2020 14:36:53 +0000, Fredxx wrote:

On 12/11/2020 08:31:14, Ian Jackson wrote:
In message , "Dave Plowman (News)"
writes
In article ,
Â* wrote:
There are 2 requirements for a good battery: voltage & current.
Terminal voltage often tells enough, but not always. The other test
is to touch probes of a 1A meter to the battery for a fraction of a
second, see how fast the needle flies up. Digital meters generally
can't do this. Keep the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed
the current range.

And if the fuse is a 'special' (like in my Fluke) it's rather
expensive.
[I think mine cost eight pounds.]

Oh dear, did you find out the hard way?

I just decided to buy a spare to fit into the little slot in the case!

About a tenner, as I recall.


--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

In article ,
Ian Jackson wrote:
In message , "Dave Plowman (News)"
writes
In article ,
wrote:
There are 2 requirements for a good battery: voltage & current.
Terminal voltage often tells enough, but not always. The other test
is to touch probes of a 1A meter to the battery for a fraction of a
second, see how fast the needle flies up. Digital meters generally
can't do this. Keep the probes on & you'll kill both meter & battery.

You'll most likely blow the fuse in the DVM if the battery can exceed
the current range.

And if the fuse is a 'special' (like in my Fluke) it's rather expensive.
[I think mine cost eight pounds.]

Yup. Makes you take care. ;-)

--
*IF ONE SYNCHRONIZED SWIMMER DROWNS, DO THE REST DROWN TOO?

Dave Plowman London SW
To e-mail, change noise into sound.

On Wednesday, 11 November 2020 at 20:36:34 UTC, Fredxx wrote:
On 11/11/2020 03:13:29, tabby wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.
I have and 1.65 is the highest I saw for a new battery. An old battery
will typically be 1V.

these weren't new batteries

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel free to get stupid again.
Perhaps it was user error then, or not recognising a malfunctioning meter?

no

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.

the measurement was not erroneous. Did I not already mention the cells had just been recharged? Short term overvoltage after charge is a routine phenomenon. Any EE knows this. 1.8v is unusually high but there ya go, consistency is not something that happens with post-charge voltage. Did we not cover this already?
Yes I did:
A well used one can go as high as 1.8v under odd circumstances. I had a couple do that earlier this year. They were well used then recharged, and gave a strangely high output. No idea why, none of the others did.


NT

On Thursday, 12 November 2020 at 00:55:46 UTC, Paul wrote:
Fredxx wrote:
On 11/11/2020 03:13:29, wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.

I have and 1.65 is the highest I saw for a new battery. An old battery
will typically be 1V.

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel
free to get stupid again.

Perhaps it was user error then, or not recognising a malfunctioning meter?

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.
Have we no electrochemists in the house ?

https://michaelbluejay.com/batteries/rechargeable.html

"NiZn's have the highest initial voltage of any rechargeable AA or
AAA battery. The nominal voltage is 1.65, and fresh out of the
charger the voltage is as high as 1.85V."

https://en.wikipedia.org/wiki/Nickel...93zinc_battery

(ˆ’) electrode: Zn + 4 OHˆ’ ‡Œ Zn(OH)42ˆ’ + 2eˆ’ (E0 = ˆ’1.2 V/SHE )

(+) electrode: 2 NiO(OH) + 2 H2O + 2 eˆ’ ‡Œ 2 Ni(OH)2 + 2 OHˆ’ (E0 = +0.50 V/SHE)

It's a redox reaction with two half-cell potentials, that give
the overall battery cell output voltage.

Was this battery mixed in with a lot of other batteries ?

Or did some other battery type leak, electrolyte got
between the inner cell metal jacket and the outer shell
steel covering ? The multimeter would need to be touching
the outer steel covering, instead of the tab on the
end, to (somehow) tap into the phantom voltage.

It makes more sense that it was a purpose-built NiZn cell.

Paul

it was a recharged alkaline or ZnC.

On 18/11/2020 02:42:32, Nick Cat wrote:
On Wednesday, 11 November 2020 at 20:36:34 UTC, Fredxx wrote:
On 11/11/2020 03:13:29, tabby wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows
the battery as good or bad (or on the margin). I
understand a zinc carbon battery has a voltage of 1.5
Volts and an alkaline battery has a voltage of 1.2
Volts? How does it know the difference between a very
good alkaline battery and a very bad zinc carbon
battery?.

An alkaline battery also has a nominal o/c voltage of
1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd
circumstances. I had a couple do that earlier this year. They
were well used then recharged, and gave a strangely high
output. No idea why, none of the others did.

Most articles suggest a brand new alkaline battery starts at
1.65V o/c and goes down from there.

Do you have reference you can cite for a well used one with a
o/c voltage of 1.8V?

no, haven't looked.
I have and 1.65 is the highest I saw for a new battery. An old
battery will typically be 1V.

these weren't new batteries

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But
feel free to get stupid again.
Perhaps it was user error then, or not recognising a malfunctioning
meter?

no

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.

the measurement was not erroneous. Did I not already mention the
cells had just been recharged?

No you didn't. Unless you're a sock pretending to be someone else and
think you have?

Short term overvoltage after charge is
a routine phenomenon. Any EE knows this.

Any EE would know that the alkaline batteries referred to by Scott and
myself were primary cells. Rechargeable alkaline never caught on for
being so poor in so many ways.

1.8v is unusually high but
there ya go, consistency is not something that happens with
post-charge voltage. Did we not cover this already? Yes I did:

You might well have done, which can only be explained as an entirely
different chemistry to the standard alkaline battery discussed here.

A well used one can go as high as 1.8v under odd circumstances. I
had a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of
the others did.

You never did answer the question, "Was this battery mixed in with a lot
of other batteries?"

A good rule is don't let your insatiable desire to be right get in the
way of facts. The alternative is to look a plonker.

On 18/11/2020 02:44:28, Nick Cat wrote:
On Thursday, 12 November 2020 at 00:55:46 UTC, Paul wrote:
Fredxx wrote:
On 11/11/2020 03:13:29, wrote:
On Tuesday, 10 November 2020 11:10:41 UTC, Fredxx wrote:
On 10/11/2020 03:04:36, tabbypurr wrote:
On Monday, 9 November 2020 10:16:51 UTC, Martin Brown wrote:
On 08/11/2020 13:59, Fredxx wrote:
On 08/11/2020 13:42:21, Scott wrote:

My multimeter has a battery test facility that shows the
battery as good or bad (or on the margin). I understand a zinc
carbon battery has a voltage of 1.5 Volts and an alkaline
battery has a voltage of 1.2 Volts? How does it know the
difference between a very good alkaline battery and a very bad
zinc carbon battery?.

An alkaline battery also has a nominal o/c voltage of 1.5V

A good fresh alkaline can be as high as 1.6v open circuit.

They start off above 1.5v. 1.5v is only nominal.

A well used one can go as high as 1.8v under odd circumstances. I had
a couple do that earlier this year. They were well used then
recharged, and gave a strangely high output. No idea why, none of the
others did.

Most articles suggest a brand new alkaline battery starts at 1.65V o/c
and goes down from there.

Do you have reference you can cite for a well used one with a o/c
voltage of 1.8V?

no, haven't looked.

I have and 1.65 is the highest I saw for a new battery. An old battery
will typically be 1V.

The only odd circumstance I can think of will be a duff meter.

I told you what the circumstances were. The meter's fine. But feel
free to get stupid again.

Perhaps it was user error then, or not recognising a malfunctioning meter?

If you have any non "stupid" reason for the erroneous measurement,
please do let us know.
Have we no electrochemists in the house ?

https://michaelbluejay.com/batteries/rechargeable.html

"NiZn's have the highest initial voltage of any rechargeable AA or
AAA battery. The nominal voltage is 1.65, and fresh out of the
charger the voltage is as high as 1.85V."

https://en.wikipedia.org/wiki/Nickel...93zinc_battery

(ˆ’) electrode: Zn + 4 OHˆ’ ‡Œ Zn(OH)42ˆ’ + 2eˆ’ (E0 = ˆ’1.2 V/SHE )

(+) electrode: 2 NiO(OH) + 2 H2O + 2 eˆ’ ‡Œ 2 Ni(OH)2 + 2 OHˆ’ (E0 = +0.50 V/SHE)

It's a redox reaction with two half-cell potentials, that give
the overall battery cell output voltage.

Was this battery mixed in with a lot of other batteries ?

Or did some other battery type leak, electrolyte got
between the inner cell metal jacket and the outer shell
steel covering ? The multimeter would need to be touching
the outer steel covering, instead of the tab on the
end, to (somehow) tap into the phantom voltage.

It makes more sense that it was a purpose-built NiZn cell.

Paul

it was a recharged alkaline

Please do give more details.

or ZnC.

So not a battery that any EE would refer to as alkaline.