The AICO mains, ionisation, wired interlinked, "non-replaceable"
lithium battery backed up, smoke alarms are coming up to 10 years old
so approaching "end of life". One has started beeping and has been
removed (for the time being) and on investigation the nominal 3 V Li
batteries are down nearer 2.6 V each.

Looking around it seems that for landings/hallways, where these smoke
alarms are, the ionisation type is depreciated these days in favour
of optical.

CPC have the batteries at just over £4 each inc VAT. Or I can get a
new optical with user replaceable alkaline battery backup for around
£27.

Presumably the ionisation type age as the amount of active Americium
241 declines but with half like of 432 years is that real problem? If
I replaced the batteries would it be a problem at 20 years of age?

Presumably an optical sensor doesn't age?

Can't decide between replacing the Li batteries and thus keeping the
Americium 241 out of land fill or dumping them (they work according
to the "test" button) and consuming more resources in getting new
optical.

--
Cheers
Dave.

Hmm, I have to say I've not found problems with the ionising type myself
since many years ago, when an early one got very insensitive and made me
wonder if the source had the capacity to damage the chip.
It says on all my alarms, do not dispose of in general trash, take to a
recycling centre.
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.
"Dave Liquorice" wrote in message
idual.net...
The AICO mains, ionisation, wired interlinked, "non-replaceable"
lithium battery backed up, smoke alarms are coming up to 10 years old
so approaching "end of life". One has started beeping and has been
removed (for the time being) and on investigation the nominal 3 V Li
batteries are down nearer 2.6 V each.

Looking around it seems that for landings/hallways, where these smoke
alarms are, the ionisation type is depreciated these days in favour
of optical.

CPC have the batteries at just over £4 each inc VAT. Or I can get a
new optical with user replaceable alkaline battery backup for around
£27.

Presumably the ionisation type age as the amount of active Americium
241 declines but with half like of 432 years is that real problem? If
I replaced the batteries would it be a problem at 20 years of age?

Presumably an optical sensor doesn't age?

Can't decide between replacing the Li batteries and thus keeping the
Americium 241 out of land fill or dumping them (they work according
to the "test" button) and consuming more resources in getting new
optical.

--
Cheers
Dave.

On 18/10/2020 14:13, Dave Liquorice wrote:
The AICO mains, ionisation, wired interlinked, "non-replaceable"
lithium battery backed up, smoke alarms are coming up to 10 years old
so approaching "end of life". One has started beeping and has been
removed (for the time being) and on investigation the nominal 3 V Li
batteries are down nearer 2.6 V each.

Looking around it seems that for landings/hallways, where these smoke
alarms are, the ionisation type is depreciated these days in favour
of optical.

CPC have the batteries at just over £4 each inc VAT. Or I can get a
new optical with user replaceable alkaline battery backup for around
£27.

Presumably the ionisation type age as the amount of active Americium
241 declines but with half like of 432 years is that real problem? If
I replaced the batteries would it be a problem at 20 years of age?

Presumably an optical sensor doesn't age?

Can't decide between replacing the Li batteries and thus keeping the
Americium 241 out of land fill or dumping them (they work according
to the "test" button) and consuming more resources in getting new
optical.

The reason they are swapped after 10 years is because of "dust build up"
and to keep the manufactures in business.

BTW AICO tell you not to test their smokes with smoke cans as "they
cause a film of grease on the detectors".

A new battery and the detector will be good for another 10 years.

--
Adam

Dave Liquorice wrote:

keeping the Americium 241 out of land fill

Drop the off at your local fire-station, they send them off for proper
processing (they generally have a box of them chirping randomly in a
corner somewhere).

On 18 Oct 2020 at 15:05:16 BST, ""Brian Gaff""
wrote:

Hmm, I have to say I've not found problems with the ionising type myself
since many years ago, when an early one got very insensitive and made me
wonder if the source had the capacity to damage the chip.
It says on all my alarms, do not dispose of in general trash, take to a
recycling centre.
Brian

I think it says that on all electronic equipment nowadays. WEEEE regulations
or something.

--
Roger Hayter

On 18/10/2020 14:13, Dave Liquorice wrote:
The AICO mains, ionisation, wired interlinked, "non-replaceable"
lithium battery backed up, smoke alarms are coming up to 10 years old
so approaching "end of life". One has started beeping and has been
removed (for the time being) and on investigation the nominal 3 V Li
batteries are down nearer 2.6 V each.

Yup similar here - none are beeping, but getting close to the ten year
mark.

Looking around it seems that for landings/hallways, where these smoke
alarms are, the ionisation type is depreciated these days in favour
of optical.

CPC have the batteries at just over £4 each inc VAT. Or I can get a
new optical with user replaceable alkaline battery backup for around
£27.

Presumably the ionisation type age as the amount of active Americium
241 declines but with half like of 432 years is that real problem? If
I replaced the batteries would it be a problem at 20 years of age?

Presumably an optical sensor doesn't age?

The ageing is more about build up of dust and the life of other
electronic components rather than the ionisation source directly.

Can't decide between replacing the Li batteries and thus keeping the
Americium 241 out of land fill or dumping them (they work according
to the "test" button) and consuming more resources in getting new
optical.

Well chances are they would carry on working ok with a new battery.

However, how much time and effort is it worth to "repair" them compared
to the new cost - especially if there is any doubt about their ongoing
sensitivity (since you life may we depend on it)?



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sun, 18 Oct 2020 14:13:27 +0100 (BST), "Dave Liquorice"
wrote:

The AICO mains, ionisation, wired interlinked, "non-replaceable"
lithium battery backed up, smoke alarms are coming up to 10 years old
so approaching "end of life". One has started beeping and has been
removed (for the time being) and on investigation the nominal 3 V Li
batteries are down nearer 2.6 V each.

Looking around it seems that for landings/hallways, where these smoke
alarms are, the ionisation type is depreciated these days in favour
of optical.

CPC have the batteries at just over £4 each inc VAT. Or I can get a
new optical with user replaceable alkaline battery backup for around
£27.

Presumably the ionisation type age as the amount of active Americium
241 declines but with half like of 432 years is that real problem? If
I replaced the batteries would it be a problem at 20 years of age?

Presumably an optical sensor doesn't age?

Can't decide between replacing the Li batteries and thus keeping the
Americium 241 out of land fill or dumping them (they work according
to the "test" button) and consuming more resources in getting new
optical.
Around here (Hertfordshire) the fire & rescue people will give people
over 65 alarms for free, and even come and fit (sticky pad) them if
you don't like climbing up a pair of steps (or balancing in a kitchen
chair) - still for free..

On Sunday, 18 October 2020 14:13:33 UTC+1, Dave Liquorice wrote:

The AICO mains, ionisation, wired interlinked, "non-replaceable"
lithium battery backed up, smoke alarms are coming up to 10 years old
so approaching "end of life". One has started beeping and has been
removed (for the time being) and on investigation the nominal 3 V Li
batteries are down nearer 2.6 V each.

Looking around it seems that for landings/hallways, where these smoke
alarms are, the ionisation type is depreciated these days in favour
of optical.

CPC have the batteries at just over £4 each inc VAT. Or I can get a
new optical with user replaceable alkaline battery backup for around
£27.

Presumably the ionisation type age as the amount of active Americium
241 declines but with half like of 432 years is that real problem? If
I replaced the batteries would it be a problem at 20 years of age?

Presumably an optical sensor doesn't age?

Can't decide between replacing the Li batteries and thus keeping the
Americium 241 out of land fill or dumping them (they work according
to the "test" button) and consuming more resources in getting new
optical.

Ionisation detects a fire earlier, giving you more time to get out. The downside is they're oversensitive to normal kitchen events like well done toast. If yours isn't producing false alarms it's better than an optical detector. So if it works I'd give it a new battery.

Both types are affected by dust, but optical more so. It might appreciate a good blow.

Am decay is a nonissue. Keep it for centuries and it might be.


NT

On Mon, 26 Oct 2020 17:44:07 -0700 (PDT), wrote:

Can't decide between replacing the Li batteries and thus keeping
the
Americium 241 out of land fill or dumping them (they work
according
to the "test" button) and consuming more resources in getting new
optical.

Went for 3 x Li rechargeables from CPC just over £12. Five minutes to
install. Unit no longer bleeps and sounds when test button pressed.
B-) I might waft some real smoke in its general direction one day.

Half life of Am is over 400 years but I suspect they are
intrinsically "fail safe" as it's the current flow between plates due
to the ionisation of the air that holds the alarm off. Take away the
ionising radiation, current stops and the alarm goes off. The test
button should break the circuit so should be a reliable indication
all is well. Don't know how the test button on an optical one works.

Cumbria Fire and Rescue also do a home check and fit smoke alarms but
they are the simple standalone battery only jobbies not mains
interlinked ones.

--
Cheers
Dave.

On Friday, 30 October 2020 13:23:09 UTC, Dave Liquorice wrote:
On Mon, 26 Oct 2020 17:44:07 -0700 (PDT), tabbypurr wrote:

I didn't

Can't decide between replacing the Li batteries and thus keeping
the
Americium 241 out of land fill or dumping them (they work
according
to the "test" button) and consuming more resources in getting new
optical.

Went for 3 x Li rechargeables from CPC just over £12. Five minutes to
install. Unit no longer bleeps and sounds when test button pressed.
B-) I might waft some real smoke in its general direction one day.

Half life of Am is over 400 years but I suspect they are
intrinsically "fail safe" as it's the current flow between plates due
to the ionisation of the air that holds the alarm off. Take away the
ionising radiation, current stops and the alarm goes off.

I believe it's the other way round.

The test
button should break the circuit so should be a reliable indication
all is well. Don't know how the test button on an optical one works.

it doesn't test the detector

NT

Cumbria Fire and Rescue also do a home check and fit smoke alarms but
they are the simple standalone battery only jobbies not mains
interlinked ones.

On Sat, 31 Oct 2020 15:45:55 -0700 (PDT), wrote:

Half life of Am is over 400 years but I suspect they are
intrinsically "fail safe" as it's the current flow between plates
due
to the ionisation of the air that holds the alarm off. Take away
the
ionising radiation, current stops and the alarm goes off.

I believe it's the other way round.

Nope, alpha radiation from the Am ionises the air, the plates have a
voltage between them so the generated ions whizz off to their
opposite charge plate causing a current to flow in the circuit
between the plates. Smoke absorbs/slows some of the ions, reducing
the current triggering the alarm.

So removing, or having much reduced radiation from, the Am would
trigger the alarm.

Don't know how the test button on an optical one works.

it doesn't test the detector

So not a real test is it? B-)

--
Cheers
Dave.