I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?

Thanks,

Daniele
--
Apple Juice Ltd
Chapter Arts Centre
Market Road www.apple-juice.co.uk
Cardiff CF5 1QE 029 2019 0140

"D.M. Procida" wrote in message
...
I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?

Always test cells and/or batteries with a suitable load which will vary with
type and size of cell. Under no load conditions your voltmeter is likely to
register the basic chemical emf of the cell, and the effects of internal
resistance will not be registered. From memory, I think about 1 volt per cell is
about right for a NiCd or NiMH cell - measured under load, of course. This
rises to over 1.2v when charged, and even higher when being charged.

--
M Stewart
Milton Keynes, UK
www.megalith.freeserve.co.uk/oddimage.htm
http://myweb.tiscali.co.uk/ms1938/

In article
,
D.M. Procida wrote:
From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?

1.4 under load should be fine. Most electronics will work with them down
to about 1 volt. Things like torches or motors might not perform quite as
well. ;-)

--
*When the chips are down, the buffalo is empty.

Dave Plowman London SW 12
RIP Acorn

In message ,
(D.M. Procida) wrote:

I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?


IME there is no easy answer to this question, but as a rule-of-thumb
this is what I do:

A brand new alkaline will register well over 1.5V (between 1.6V and
1.7V) on a high-impedance multimeter off load.

A part-used alkaline which has been off-load for several hours and
measures less than 1.5V doesn't have much life left.

Down to about 1.4V you'll still get a reasonable amount of use from an
Alkaline in low-power devices such as clocks, remote controls and small
portable radios, but not in high-power devices such as torches or
anything with a motor.

Below 1.4V it is rarely worth re-using the cell and I dispose of them.

9V alkalines get thrown when they are down to maybe 8.5V.

For example, a Maglite which takes 2 AA batteries may begin to look a
bit dim so you change the batteries. You may find however that there is
enough life left in them to power your 2xAA tranny for a week or two of
normal use.

As others have said though, the amount of use to expect varies depending
on the actual load. These figures of course only apply to alkaline cells
and *not* to zinc-carbon or zinc-chloride batteries which have the same
nominal voltages but different characteristics. Rechargeables have both
different voltages and different discharge characteristics and there are
other experts on this group in that field.

Just my 2p.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
.... (C)ontrol (A)lt (B)ye

On Fri, 14 May 2004 08:53:00 +0100,
(D.M. Procida) wrote:

I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?

Thanks,

Daniele

Hi,

Half dead alkalines work quite well in clocks, remote controls and
other low drain uses.

cheers,
Pete.

"Martin Angove" wrote in message
...
In message ,
(D.M. Procida) wrote:

I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?


IME there is no easy answer to this question, but as a rule-of-thumb
this is what I do:

A brand new alkaline will register well over 1.5V (between 1.6V and
1.7V) on a high-impedance multimeter off load.

A part-used alkaline which has been off-load for several hours and
measures less than 1.5V doesn't have much life left.

Down to about 1.4V you'll still get a reasonable amount of use from an
Alkaline in low-power devices such as clocks, remote controls and small
portable radios, but not in high-power devices such as torches or
anything with a motor.

Below 1.4V it is rarely worth re-using the cell and I dispose of them.

9V alkalines get thrown when they are down to maybe 8.5V.

For example, a Maglite which takes 2 AA batteries may begin to look a
bit dim so you change the batteries. You may find however that there is
enough life left in them to power your 2xAA tranny for a week or two of
normal use.

As others have said though, the amount of use to expect varies depending
on the actual load. These figures of course only apply to alkaline cells
and *not* to zinc-carbon or zinc-chloride batteries which have the same
nominal voltages but different characteristics. Rechargeables have both
different voltages and different discharge characteristics and there are
other experts on this group in that field.

Just my 2p.

Hwyl!

M.

--
Martin Angove: http://www.tridwr.demon.co.uk/
Two free issues: http://www.livtech.co.uk/ Living With Technology
... (C)ontrol (A)lt (B)

Martin,

I reckon your voltmeter is reading about 0.15 volts high - alkalines still have usable
life left in them at 1.35 volts off load.
and I have rarely checked new cells at above 1.60 volts - measured using professional
(calibrated) test kit, and at normal
UK room temperatures, and my findings are consistent with manufacturers data.......

Nick

"Pete C" wrote in message
...
On Fri, 14 May 2004 08:53:00 +0100,
(D.M. Procida) wrote:

I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?

Thanks,

Daniele

Hi,

If they're small batteries ( i.e. AA or AAA ) then I find that shorting them
with the multimeter leads when the multimeter is turned to current gives a
good indication of their state. From memory, an AA cell will deliver some
1.5A into a short when newish. Of course, make sure your multimeter can take
this current, and only do it momentarily. I used an old AVO meter, the
result you get may vary with the internal resistance of your ammeter when
set to 'current'.

Andy.

On Fri, 14 May 2004 08:53:00 +0100, D.M. Procida wrote:

I've got a bunch of alkaline cells here, and I'm wondering which of them
are going to be any good at all. What should I use as a cut-off voltage
when I'm deciding? I have a multimeter, which also has a battery tester
(I guess it just puts a bit of a load on them).

From one set I get around 1.4V with the battery tester, 1.45 with the
voltmeter. But while that sounds pretty good, I know that in practice
they were useless. How much do 'rested' alkaline cells recover after
use?

IME 1.6 is brand new & falls very quickly to 1.5 stays there for a long
while drifting slowly down to 1.45 as it begins to die.
Sub 1.4 V is effectively dead.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html