I have an electronic scale that uses a 9v battery and it says "use alkaline
batteries only". I prefer to use rechargeable NiMH batteries. How can the
product tell the difference (or can it) and what would be the problem, if
any, of using non-alkaline batteries in such a product.

Thanks,
noozer

BE wrote in
:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.

Thanks,
noozer


Rechargable batteries tend to have a lower voltage than non-rechargable,
so the voltage difference might cause trouble. My guess is the "Use
alkaline batteries only" is there because the manufacturer knows the
device likes to eat batteries for breakfast, lunch, and dinner.

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm

Meat Plow ) writes:
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH batteries.
How can the product tell the difference (or can it) and what would be the
problem, if any, of using non-alkaline batteries in such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an alkaline. The
rechargable stays more constant then drops off rapidly. Hence the scale
will operate longer on an alkaline.

Maybe more important, rechargeables don't start with the same voltage
level as fresh alkalines, and if the unit counts on the voltage being
above a certain point, the useable "life" of the rechargeable will
not be so long (though of course, they can be recharged).

I used to have something, it might have been my Radio Shack Model
100 laptop, that I used rechargeables in, and they sure didn't last
as long as alkalines. On the other hand, the rechargeables could
be recharged so I got more long term life out of them than the alkalines.

Michael

(Michael Black) writes:

Meat Plow ) writes:
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH batteries.
How can the product tell the difference (or can it) and what would be the
problem, if any, of using non-alkaline batteries in such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an alkaline. The
rechargable stays more constant then drops off rapidly. Hence the scale
will operate longer on an alkaline.

Maybe more important, rechargeables don't start with the same voltage
level as fresh alkalines, and if the unit counts on the voltage being
above a certain point, the useable "life" of the rechargeable will
not be so long (though of course, they can be recharged).

I used to have something, it might have been my Radio Shack Model
100 laptop, that I used rechargeables in, and they sure didn't last
as long as alkalines. On the other hand, the rechargeables could
be recharged so I got more long term life out of them than the alkalines.

The bottom line is it almost certainly won't hurt the equipment so may be
worth trying. For something like an electronic scale, rechargeables
may indeed be fine.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

BE wrote:
I have an electronic scale that uses a 9v battery and it says "use alkaline
batteries only". I prefer to use rechargeable NiMH batteries. How can the
product tell the difference (or can it) and what would be the problem, if
any, of using non-alkaline batteries in such a product.


Hi...

The voltage of a brand new alkaline is 1.5 volts. The
voltage of a freshly charged nimh or nicd is 1.2 volts.

The likelihood is that your scale will see the 1.2 volts,
and decide that the battery is due for replacement - at worst
refuse to operate; at best tell you to change the battery.

Take care.

Ken

"Puckdropper" wrote in message
reenews.net...
BE wrote in
:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.

Thanks,
noozer


Rechargable batteries tend to have a lower voltage than non-rechargable,
so the voltage difference might cause trouble. My guess is the "Use
alkaline batteries only" is there because the manufacturer knows the
device likes to eat batteries for breakfast, lunch, and dinner.

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm

Or pehaps the current drain is so low that alkalines will last for years,
and rechargables will self discharge in days to weeks. For low drain
devices like clocks, calculators, and scales with LCD displays, or other
infrequently used devices, rechargables do not really make sense. Alkalines
have a shelf life of several years.

CK

In article ews.net,
Puckdropper wrote:
Rechargable batteries tend to have a lower voltage than non-rechargable,
so the voltage difference might cause trouble. My guess is the "Use
alkaline batteries only" is there because the manufacturer knows the
device likes to eat batteries for breakfast, lunch, and dinner.

However, the terminal usable voltage of an alkaline will be very similar
to that of a Ni-Cad, etc.

--
*Succeed, in spite of management *

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

"Dave Plowman (News)" wrote:

In article ews.net,
Puckdropper wrote:
Rechargable batteries tend to have a lower voltage than non-rechargable,
so the voltage difference might cause trouble. My guess is the "Use
alkaline batteries only" is there because the manufacturer knows the
device likes to eat batteries for breakfast, lunch, and dinner.

However, the terminal usable voltage of an alkaline will be very similar
to that of a Ni-Cad, etc.

I discovered recently that Duracell quote battery lifetime to 50% of initial
voltage ! Any rechargeable will be far better.

Graham

Ken Weitzel wrote:

BE wrote:
I have an electronic scale that uses a 9v battery and it says "use alkaline
batteries only". I prefer to use rechargeable NiMH batteries. How can the
product tell the difference (or can it) and what would be the problem, if
any, of using non-alkaline batteries in such a product.


Hi...

The voltage of a brand new alkaline is 1.5 volts. The
voltage of a freshly charged nimh or nicd is 1.2 volts.

The likelihood is that your scale will see the 1.2 volts,
and decide that the battery is due for replacement - at worst
refuse to operate; at best tell you to change the battery.

According to Duracell, an alkaline battery isn't dead until it reaches 0.75V !

Incidentally, you can get '9V' alkalines with 7 or 8 cells ( 8.4 or 9.6 V ).

Graham

Eeyore wrote:

Ken Weitzel wrote:


BE wrote:

I have an electronic scale that uses a 9v battery and it says "use alkaline
batteries only". I prefer to use rechargeable NiMH batteries. How can the
product tell the difference (or can it) and what would be the problem, if
any, of using non-alkaline batteries in such a product.


Hi...

The voltage of a brand new alkaline is 1.5 volts. The
voltage of a freshly charged nimh or nicd is 1.2 volts.

The likelihood is that your scale will see the 1.2 volts,
and decide that the battery is due for replacement - at worst
refuse to operate; at best tell you to change the battery.


According to Duracell, an alkaline battery isn't dead until it reaches 0.75V !

Incidentally, you can get '9V' alkalines with 7 or 8 cells ( 8.4 or 9.6 V ).


You mean NiCd? Most "9V" rechareables are 7.2V. 9V alkaline batteries
consist of 6 1.5V cells which add up to an even 9V.

Meat Plow wrote in
news
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an alkaline.
The rechargable stays more constant then drops off rapidly. Hence the
scale will operate longer on an alkaline.


Does anyone MAKE a "9V" NiMH battery?

--
Jim Yanik
jyanik
at
kua.net

Sam Goldwasser wrote in
:

(Michael Black) writes:

Meat Plow ) writes:
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries
in such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an
alkaline. The rechargable stays more constant then drops off
rapidly. Hence the scale will operate longer on an alkaline.

Maybe more important, rechargeables don't start with the same voltage
level as fresh alkalines, and if the unit counts on the voltage being
above a certain point, the useable "life" of the rechargeable will
not be so long (though of course, they can be recharged).

I used to have something, it might have been my Radio Shack Model
100 laptop, that I used rechargeables in, and they sure didn't last
as long as alkalines. On the other hand, the rechargeables could
be recharged so I got more long term life out of them than the
alkalines.

The bottom line is it almost certainly won't hurt the equipment so may
be worth trying. For something like an electronic scale,
rechargeables may indeed be fine.


For an electronic scale,I'd use a wallwart.

--
Jim Yanik
jyanik
at
kua.net

"CJK" wrote in
:


"Puckdropper" wrote in message
reenews.net...
BE wrote in
:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries
in such a product.

Thanks,
noozer


Rechargable batteries tend to have a lower voltage than
non-rechargable, so the voltage difference might cause trouble. My
guess is the "Use alkaline batteries only" is there because the
manufacturer knows the device likes to eat batteries for breakfast,
lunch, and dinner.

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm

Or pehaps the current drain is so low that alkalines will last for
years, and rechargables will self discharge in days to weeks. For low
drain devices like clocks, calculators, and scales with LCD displays,
or other infrequently used devices, rechargables do not really make
sense. Alkalines have a shelf life of several years.

CK



Very good point!

--
Jim Yanik
jyanik
at
kua.net

Ken Weitzel wrote in
news:vL9Xg.123066$5R2.19152@pd7urf3no:

BE wrote:
I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.


Hi...

The voltage of a brand new alkaline is 1.5 volts. The
voltage of a freshly charged nimh or nicd is 1.2 volts.

actually,it's more like 1.4v



--
Jim Yanik
jyanik
at
kua.net

James Sweet wrote:

Eeyore wrote:
Ken Weitzel wrote:
BE wrote:

I have an electronic scale that uses a 9v battery and it says "use alkaline
batteries only". I prefer to use rechargeable NiMH batteries. How can the
product tell the difference (or can it) and what would be the problem, if
any, of using non-alkaline batteries in such a product.


Hi...

The voltage of a brand new alkaline is 1.5 volts. The
voltage of a freshly charged nimh or nicd is 1.2 volts.

The likelihood is that your scale will see the 1.2 volts,
and decide that the battery is due for replacement - at worst
refuse to operate; at best tell you to change the battery.


According to Duracell, an alkaline battery isn't dead until it reaches 0.75V !

Incidentally, you can get '9V' alkalines with 7 or 8 cells ( 8.4 or 9.6 V ).

You mean NiCd? Most "9V" rechareables are 7.2V. 9V alkaline batteries
consist of 6 1.5V cells which add up to an even 9V.

NiMH. I don't know what made me type alkaline !

I have one right here that I recharged a month or two ago and its current terminal
voltage is 8.99V.

Graham

Jim Yanik wrote:

Meat Plow wrote
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an alkaline.
The rechargable stays more constant then drops off rapidly. Hence the
scale will operate longer on an alkaline.

Does anyone MAKE a "9V" NiMH battery?

I have one in front of me ( a cheapie ) that I recharged a month or two
back.

It currently measures 8.99V.

Graham

Jim Yanik wrote:

Ken Weitzel wrote
BE wrote:
I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.


Hi...

The voltage of a brand new alkaline is 1.5 volts. The
voltage of a freshly charged nimh or nicd is 1.2 volts.

actually,it's more like 1.4v

1.3 but not for long.

Graham

On 10/11/06 6:52 PM, in article ,
"Jim Yanik" wrote:

Meat Plow wrote in
news
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an alkaline.
The rechargable stays more constant then drops off rapidly. Hence the
scale will operate longer on an alkaline.


Does anyone MAKE a "9V" NiMH battery?

I just bought several Energizer Rechargeable "9v" batteries (NiMH) and,
thanks to a previous post, I looked at the fine print and, yes, it is
actually 7.2volts! It says: "Size 9v" - so they can claim it is a 9v
battery due to the loose use of the term "9v" to indicate a "size" rather
than a power potential.

Why would the makers of these rechargeables make them not truly match the
voltage they are supposed to be?

noozer

BE ) writes:
On 10/11/06 6:52 PM, in article ,
"Jim Yanik" wrote:

Meat Plow wrote in
news
On Wed, 11 Oct 2006 14:47:28 +0000, BE Has Frothed:

I have an electronic scale that uses a 9v battery and it says "use
alkaline batteries only". I prefer to use rechargeable NiMH
batteries. How can the product tell the difference (or can it) and
what would be the problem, if any, of using non-alkaline batteries in
such a product.

Thanks,
noozer

As they discharge, the voltage drops off more linear in an alkaline.
The rechargable stays more constant then drops off rapidly. Hence the
scale will operate longer on an alkaline.


Does anyone MAKE a "9V" NiMH battery?

I just bought several Energizer Rechargeable "9v" batteries (NiMH) and,
thanks to a previous post, I looked at the fine print and, yes, it is
actually 7.2volts! It says: "Size 9v" - so they can claim it is a 9v
battery due to the loose use of the term "9v" to indicate a "size" rather
than a power potential.

Why would the makers of these rechargeables make them not truly match the
voltage they are supposed to be?

Because it's a chemical matter.

A cell puts out about 1.5v. If you need more voltage, you combine them.
So when the need for 9v batteries came along, they had to combine six
cells in the package. Or maybe they decided on package size, and then
picked a voltage that would fit the package. Open up a 9v battery,
and you'll see six invidual cells. In some, it's 6 sort of lumps, but
in others it's sort of like skinny AAA cells inside. If they needed
more voltage, they'd have to add more cells, and the package would be
bigger for the same amount of current.

Nicads put out about 1.2v. That too is a chemical issue. The only
way they can get a higher voltage is by combining cells in the same
package, but that cuts current capacity (since the cells would
be smaller), and results in not the needed 1.5v but 2.4 volts.

So when they combine 6 nicad cells in a "9v battery" package,
6 * 1.2 =7.2volts. Again, the only way to fix that is by putting
mroe cells inside that package, and while that's more feasible than
with a straight AA cell, it forces each to be a physically smaller
cell and that likely impacts on the current the whole thing
can supply.

In some cases, equipment has been designed with all this in mind.
The battery compartment will be big enough to accomodate more
batteries than the needed voltage would require in alkaline batteries.
So that old CB walkie talkie would have a place for 10 AA batteries,
so if they are nicads it gets 12v. It would then come with a pair
of dummy AAs, that merely fill space and provide contact end to end,
so when using alkaline AAs you would simply put in 10 AAs and the
dummies, and still get 12volts.

Michael

BE wrote:

"Jim Yanik" wrote:

Does anyone MAKE a "9V" NiMH battery?

I just bought several Energizer Rechargeable "9v" batteries (NiMH) and,
thanks to a previous post, I looked at the fine print and, yes, it is
actually 7.2volts! It says: "Size 9v" - so they can claim it is a 9v
battery due to the loose use of the term "9v" to indicate a "size" rather
than a power potential.

Why would the makers of these rechargeables make them not truly match the
voltage they are supposed to be?

Because they like fat profits ?

Buy the chaep ones instead. I did and it is actually 9V.

Graham

In article ,
BE wrote:
I just bought several Energizer Rechargeable "9v" batteries (NiMH) and,
thanks to a previous post, I looked at the fine print and, yes, it is
actually 7.2volts! It says: "Size 9v" - so they can claim it is a 9v
battery due to the loose use of the term "9v" to indicate a "size" rather
than a power potential.

Why would the makers of these rechargeables make them not truly match the
voltage they are supposed to be?

Because upping the number of cells within the same package may not result
in any real benefits. Indeed, apart from increasing the cost, it may end
up with a lower capacity. It depends on how sensitive the device is to
voltages at the lower end of what an alkaline cell produces.

--
*According to my calculations, the problem doesn't exist.

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

In article , Eeyore
wrote:
I just bought several Energizer Rechargeable "9v" batteries (NiMH)
and, thanks to a previous post, I looked at the fine print and, yes,
it is actually 7.2volts! It says: "Size 9v" - so they can claim it is
a 9v battery due to the loose use of the term "9v" to indicate a
"size" rather than a power potential.

Why would the makers of these rechargeables make them not truly match
the voltage they are supposed to be?

Because they like fat profits ?

Buy the chaep ones instead. I did and it is actually 9V.

If you're talking Ni-Cads or NiMH, it's unlikely to be a 8 cell PP3 if
cheap.

The initial open circuit voltage of a Ni-Cad is pretty irrelevant. After a
short time under load it will settle at 1.2v per cell and stay there for
most of the usable range. Alkalines are dying from the second they're
used. ;-)

--
*Why don't you ever see the headline "Psychic Wins Lottery"?

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

Coming back to the original posting, the manufacturer was probably suggesting the use of alkaline batteries is preferred - as against carbon zinc types with their inherently poor shelf life and leaking electrolyte.