While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons. Both have PP3 batteries currently showing about 8.5 volts, so I've still no idea which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I have a vague memory that zinc chloride ones actually last longer for very low consumption tasks, such as door bells and smoke alarms. Is this right?


--
Clive Page

In article ,
Clive Page writes:
While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons. Both have PP3 batteries currently showing about 8.5 volts, so I've still no idea which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I have a vague memory that zinc chloride ones actually last longer for very low consumption tasks, such as door bells and smoke alarms. Is this right?

For smoke alarms on PP3's, I use alkaline, and replace annually.
They last longer than a year, but not 2 years, but it's easy to
nominate a date, such as your birthday, or Christmas, when you
routinely replace them.

I did buy some of the long life lithum PP3 cells, and they worked
for a year or two, but then the detectors started bleeping.
However, the batteries are 11V, so I presume this is due to too
high voltage, although I'm not sure why they worked for some time
before that.

Most of mine run off the burglar alarm supply, so there are no
batteries to change in them, but I look after various battery
ones around the family.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

To be honest, I've not noticed much difference except that some seem to be
harder to push the connectors onto!

Brian

--
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This newsgroup posting comes to you directly from...
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Blind user, so no pictures please!
"Clive Page" wrote in message
...
While lying awake last night I heard short beeps at long intervals, almost
certainly a smoke alarm trying to tell me its battery was low, but I
couldn't be bothered to get up to find which one (of two) it was. In the
morning, by some variant of Murphy's Law, the beeping had stopped but both
worked perfectly well when I pressed their test buttons. Both have PP3
batteries currently showing about 8.5 volts, so I've still no idea which
one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I
have a vague memory that zinc chloride ones actually last longer for very
low consumption tasks, such as door bells and smoke alarms. Is this
right?

--
Clive Page

Over voltage is not a problem. the problem is internal resistance, ie they
may measure high on small loads, but when they do a test they momentarily
take more current, ie with the bleeper and hence their voltage starts to
drop due to the internal resistance.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Andrew Gabriel" wrote in message
news
In article ,
Clive Page writes:
While lying awake last night I heard short beeps at long intervals,
almost certainly a smoke alarm trying to tell me its battery was low, but
I couldn't be bothered to get up to find which one (of two) it was. In
the morning, by some variant of Murphy's Law, the beeping had stopped but
both worked perfectly well when I pressed their test buttons. Both have
PP3 batteries currently showing about 8.5 volts, so I've still no idea
which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I
have a vague memory that zinc chloride ones actually last longer for very
low consumption tasks, such as door bells and smoke alarms. Is this
right?

For smoke alarms on PP3's, I use alkaline, and replace annually.
They last longer than a year, but not 2 years, but it's easy to
nominate a date, such as your birthday, or Christmas, when you
routinely replace them.

I did buy some of the long life lithum PP3 cells, and they worked
for a year or two, but then the detectors started bleeping.
However, the batteries are 11V, so I presume this is due to too
high voltage, although I'm not sure why they worked for some time
before that.

Most of mine run off the burglar alarm supply, so there are no
batteries to change in them, but I look after various battery
ones around the family.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Fri, 16 Mar 2018 14:36:27 -0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Clive Page writes:
While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons. Both have PP3 batteries currently showing about 8.5 volts, so I've still no idea which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I have a vague memory that zinc chloride ones actually last longer for very low consumption tasks, such as door bells and smoke alarms. Is this right?

For smoke alarms on PP3's, I use alkaline, and replace annually.
They last longer than a year, but not 2 years, but it's easy to
nominate a date, such as your birthday, or Christmas, when you
routinely replace them.

I'm sure mine last far longer than two years. If you buy ones that
don't have replaceable batteries I thought they lasted five years. Why
would quality batteries be any different?

I did buy some of the long life lithum PP3 cells, and they worked
for a year or two, but then the detectors started bleeping.
However, the batteries are 11V, so I presume this is due to too
high voltage, although I'm not sure why they worked for some time
before that.

How can they be too high a voltage? Are batteries not 12 Volts
nominal?

Most of mine run off the burglar alarm supply, so there are no
batteries to change in them, but I look after various battery
ones around the family.

I assume your burglar alarm system has a battery to cover power
failures.

Clive Page wrote:

While lying awake last night I heard short beeps at long intervals, almost
certainly a smoke alarm trying to tell me its battery was low, but I
couldn't be bothered to get up to find which one (of two) it was. In the
morning, by some variant of Murphy's Law, the beeping had stopped but both
worked perfectly well when I pressed their test buttons. Both have PP3
batteries currently showing about 8.5 volts, so I've still no idea which
one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I
have a vague memory that zinc chloride ones actually last longer for very
low consumption tasks, such as door bells and smoke alarms. Is this
right?



I remember that being the received wisdom, but the specified shelf life
of alkaline batteries seems so long ahead nowadays that I wonder if it
is (still) true?



--

Roger Hayter

On 16/03/2018 14:10, Clive Page wrote:
While lying awake last night I heard short beeps at long intervals,
almost certainly a smoke alarm trying to tell me its battery was low,
but I couldn't be bothered to get up to find which one (of two) it was.
In the morning, by some variant of Murphy's Law, the beeping had stopped
but both worked perfectly well when I pressed their test buttons.

It's temperature. During the night the battery gets colder and the
terminal voltage drops.


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

On 16/03/2018 16:13, Roger Hayter wrote:


I remember that being the received wisdom, but the specified shelf life
of alkaline batteries seems so long ahead nowadays that I wonder if it
is (still) true?




Fresh Duracell Industrial (formerly Procell) alkaline batteries are
dated 2024.

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

On Fri, 16 Mar 2018 15:37:10 +0000, Scott wrote:

I did buy some of the long life lithum PP3 cells, and they worked for a
year or two, but then the detectors started bleeping. However, the
batteries are 11V, so I presume this is due to too high voltage,
although I'm not sure why they worked for some time before that.

How can they be too high a voltage? Are batteries not 12 Volts nominal?

The PP3 is a 9 volt battery.

--
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

On 16 Mar 2018 16:33:57 GMT, Bob Eager wrote:

On Fri, 16 Mar 2018 15:37:10 +0000, Scott wrote:

I did buy some of the long life lithum PP3 cells, and they worked for a
year or two, but then the detectors started bleeping. However, the
batteries are 11V, so I presume this is due to too high voltage,
although I'm not sure why they worked for some time before that.

How can they be too high a voltage? Are batteries not 12 Volts nominal?

The PP3 is a 9 volt battery.

Good point. Apologies for introducing fake news to this discussion
:-)

alan_m wrote:
On 16/03/2018 14:10, Clive Page wrote:
While lying awake last night I heard short beeps at long intervals,
almost certainly a smoke alarm trying to tell me its battery was low,
but I couldn't be bothered to get up to find which one (of two) it
was. In the morning, by some variant of Murphy's Law, the beeping
had stopped but both worked perfectly well when I pressed their test
buttons.

It's temperature. During the night the battery gets colder and the
terminal voltage drops.

That would explain why the clock in my garage lost time when it was very
cold and was fine when it got warmer.
I am enlightened.

On 16/03/2018 15:37, Scott wrote:
On Fri, 16 Mar 2018 14:36:27 -0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Clive Page writes:
While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons. Both have PP3 batteries currently showing about 8.5 volts, so I've still no idea which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I have a vague memory that zinc chloride ones actually last longer for very low consumption tasks, such as door bells and smoke alarms. Is this right?

For smoke alarms on PP3's, I use alkaline, and replace annually.
They last longer than a year, but not 2 years, but it's easy to
nominate a date, such as your birthday, or Christmas, when you
routinely replace them.

I'm sure mine last far longer than two years. If you buy ones that
don't have replaceable batteries I thought they lasted five years. Why
would quality batteries be any different?

Because they are not alkaline batteries.

Mine are supposed to last 10 years, I will let you know in 6 years if I
remember.

On Friday, 16 March 2018 14:10:46 UTC, Clive Page wrote:

While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons. Both have PP3 batteries currently showing about 8.5 volts, so I've still no idea which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I have a vague memory that zinc chloride ones actually last longer for very low consumption tasks, such as door bells and smoke alarms. Is this right?

I don't think so. ZnC/Cl leak when flat too.


NT

In article ,
Scott writes:
On Fri, 16 Mar 2018 14:36:27 -0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Clive Page writes:
While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons. Both have PP3 batteries currently showing about 8.5 volts, so I've still no idea which one it was, but I'll replace both to be on the safe side.

Although manganese alkaline batteries are better value for most things, I have a vague memory that zinc chloride ones actually last longer for very low consumption tasks, such as door bells and smoke alarms. Is this right?

For smoke alarms on PP3's, I use alkaline, and replace annually.
They last longer than a year, but not 2 years, but it's easy to
nominate a date, such as your birthday, or Christmas, when you
routinely replace them.

I'm sure mine last far longer than two years. If you buy ones that
don't have replaceable batteries I thought they lasted five years. Why

10 years I think, which is because they have built-in non-
recharable lithium cells.

would quality batteries be any different?

I did buy some of the long life lithum PP3 cells, and they worked
for a year or two, but then the detectors started bleeping.
However, the batteries are 11V, so I presume this is due to too
high voltage, although I'm not sure why they worked for some time
before that.

How can they be too high a voltage? Are batteries not 12 Volts
nominal?

They're 9V labeled, but they have 3 non-rechargable lithium
cells in them which are nearly 4V each, so they're well over 9V.
It does amuse me that it says "do not incinerate" on them ;-)

Most of mine run off the burglar alarm supply, so there are no
batteries to change in them, but I look after various battery
ones around the family.

I assume your burglar alarm system has a battery to cover power
failures.

Yes, 12V. The smoke alarms are standard 9V PP3 battery alarms,
but instead of the battery, there's a PP3 sized module which drops
the 12V to 9V and measures the current. When the current increases
due to the sounder, the module signals back to the alarm panel
that the smoke sensor has triggered.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 16/03/2018 16:16, alan_m wrote:
On 16/03/2018 14:10, Clive Page wrote:
While lying awake last night I heard short beeps at long intervals, almost certainly a smoke alarm trying to tell me its battery was low, but I couldn't be bothered to get up to find which one (of two) it was. In the morning, by some variant of Murphy's Law, the beeping had stopped but both worked perfectly well when I pressed their test buttons.

It's temperature. During the night the battery gets colder and the terminal voltage drops.

I thought it might be. It's surprising that a degree or two would make that much difference though.


--
Clive Page

On 16/03/2018 22:52, Clive Page wrote:
On 16/03/2018 16:16, alan_m wrote:
On 16/03/2018 14:10, Clive Page wrote:
While lying awake last night I heard short beeps at long intervals,
almost certainly a smoke alarm trying to tell me its battery was low,
but I couldn't be bothered to get up to find which one (of two) it
was. In the morning, by some variant of Murphy's Law, the beeping had
stopped but both worked perfectly well when I pressed their test
buttons.

It's temperature. During the night the battery gets colder and the
terminal voltage drops.

I thought it might be.Â* It's surprising that a degree or two would make
that much difference though.



It only happens when the batteries are on their last legs.

But you made the right decision by deciding to swap the batteries in
both smokes and not **** about deciding if one battery is better than
the other one.


--
Adam