Clipsal smoke alarms

[Suzy]

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any comments?

 

[David L. Jones]

On Oct 17, 5:22 pm, "Suzy" <not@valid> wrote:

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high).

You mean 750R, not 750K, right?

Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any comments?

Dead ones I've pulled out of my smoke alarms were (from memory) below
8V with no load. 8.9V under load means that battery has plenty of
juice left. Something is fishy...

Dave.

 

[Doug Jewell]

"Suzy" <not@valid> wrote in message news:4715b851$1@dnews.tpgi.com.au...

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
750k at 9V is a 12uA load not 20mA. For a 20mA load at 9V you would need a

450ohm resistor.
If the battery is dropping from 9.4v to 8.9v on a 12uA load then it is
pretty flat.

Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I
wouldn't have thought the inbuilt low battery alarm was so sensitive. Any
comments?

 

[Suzy]

"David L. Jones" <altzone@gmail.com> wrote in message
news:1192606659.581689.238040@z24g2000prh.googlegroups.com...

On Oct 17, 5:22 pm, "Suzy" <not@valid> wrote:
We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K
(giving
approx 20 mA load - probably much too high).

You mean 750R, not 750K, right?

Yeah, I meant that, Dave!

Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I
wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any
comments?

Dead ones I've pulled out of my smoke alarms were (from memory) below
8V with no load. 8.9V under load means that battery has plenty of
juice left. Something is fishy...

Dave.

Yeah, I would have thought that!

 

[Suzy]

"Doug Jewell" <doug@dontspamme.com> wrote in message
news:4715ee57$0$11590$5a62ac22@per-qv1-newsreader-01.iinet.net.au...

"Suzy" <not@valid> wrote in message news:4715b851$1@dnews.tpgi.com.au...
We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K
(giving approx 20 mA load - probably much too high). Replaced battery
with new
750k at 9V is a 12uA load not 20mA. For a 20mA load at 9V you would need a
450ohm resistor.
If the battery is dropping from 9.4v to 8.9v on a 12uA load then it is
pretty flat.

Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I
wouldn't have thought the inbuilt low battery alarm was so sensitive. Any
comments?

Agreed. I meant 750R of course!

 

[Trevor Wilson]

"Suzy" <not@valid> wrote in message news:4715b851$1@dnews.tpgi.com.au...

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I
wouldn't have thought the inbuilt low battery alarm was so sensitive. Any
comments?

**I decided to fit some mains powered smoke alarms in my last home. I chose
some fairly expensive ones, which had a battery back up. After climbing
ladders to get into the ceiling space at 2AM to disconnect the power
(twice), I decided to switch to another brand. I spoke to the guy at the
electrical wholesale outlet (Turks) and asked which model was the most
reliable. I've been happy and false alarm free for several years.

Go ask the guy at the electrical wholesale outlet nearest you. They know
which models are the least troublesome. Buying smoke alarms from K-Mart (or
other, similar outlets) is the worst place to buy them.

BTW: Photo-electric is generally regarded as best for normal situations.
They're usually more expensive.

Trevor Wilson

 

[Suzy]

"Trevor Wilson" <trevor@_SPAMBLOCK_rageaudio.com.au> wrote in message
news:5nnciqFitmklU1@mid.individual.net...

**I decided to fit some mains powered smoke alarms in my last home. I
chose some fairly expensive ones, which had a battery back up. After
climbing ladders to get into the ceiling space at 2AM to disconnect the
power (twice)...

Yes, that was our problem but fortunately, I can swing down the unit from
within the house, which disconnects if (the unit) from the mains, and then
on removing the battery there are just a few shrieks as the capacitor
discharges, and then peace.

There's nothing quite so disruptive at 2 am than a beeping smoke alarm
(except possibly a smokelogged house -- hence I don't want to disable it).
Does seem however that some models are unduly sensitive to very small
battery ageing.

All Ok now with new Duracell.

 

[Franc Zabkar]

On Wed, 17 Oct 2007 17:22:52 +1000, "Suzy" <not@valid> put finger to
keyboard and composed:

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any comments?

Assuming you mean 750 ohms, then I've had similar experiences with
various smoke alarms. However, instead of discarding my "flat"
batteries, I've used them in my multimeter.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Suzy]

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message
news9goh3l86lei3ffduh4s8l724h7cf2kcos@4ax.com...

On Wed, 17 Oct 2007 17:22:52 +1000, "Suzy" <not@valid> put finger to
keyboard and composed:

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I
wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any comments?

Assuming you mean 750 ohms, then I've had similar experiences with
various smoke alarms. However, instead of discarding my "flat"
batteries, I've used them in my multimeter.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Yes, 750 ohms of course!

 

[kreed]

On Oct 22, 4:21 pm, Franc Zabkar <fzab...@iinternode.on.net> wrote:

On Wed, 17 Oct 2007 17:22:52 +1000, "Suzy" <not@valid> put finger to
keyboard and composed:

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any comments?

Assuming you mean 750 ohms, then I've had similar experiences with
various smoke alarms. However, instead of discarding my "flat"
batteries, I've used them in my multimeter.

Being environmentally responsible, and a lot more pleasant than eating

your own ear wax like some

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Franc Zabkar]

On Mon, 22 Oct 2007 16:21:21 +1000, Franc Zabkar
<fzabkar@iinternode.on.net> put finger to keyboard and composed:

On Wed, 17 Oct 2007 17:22:52 +1000, "Suzy" <not@valid> put finger to
keyboard and composed:

We have one -- the normal type that have a 9v battery and fit to the
ceiling. It started beeping intermittently (and loudly) so investigated.
"Old" battery showed 9.4 v dropping to 8.9 v when loaded with 750K (giving
approx 20 mA load - probably much too high). Replaced battery with new
Duracell which gave 9.7 v dropping to 9.6 on load. No beeps now. I wouldn't
have thought the inbuilt low battery alarm was so sensitive. Any comments?

Assuming you mean 750 ohms, then I've had similar experiences with
various smoke alarms. However, instead of discarding my "flat"
batteries, I've used them in my multimeter.

I just had an Eveready "Super Heavy Duty" battery go flat in a $5
smoke alarm. It measured 7.7V on no load and it overranged (> 100
ohms) on Bob Parker's ESR meter.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.