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From: tomb@hplsla.HP.COM (Tom Bruhns)
Newsgroups: sci.electronics
Subject: Re: Reply:  NiCads in Smoke Detectors
Message-ID: <5170116@hplsla.HP.COM>
Date: 3 Mar 91 02:15:12 GMT
References: <1991Mar1.145532.7118@lonex.radc.af.mil>
Organization: HP Lake Stevens, WA
Lines: 24

vanderwerkend@lonex.radc.af.mil (Dan Vanderwerken) writes:
>In article <233@pieta.gtephx.UUCP> you write:
>>Is it safe to use a NiCad rechargeable battery in my
>>smoke detector?  What about the "low battery" sensor
>>which automatically returns short beeps when the battery
>>gets low??
>
>IMHO, putting a NiCad into a smoke detector is a waste of valuable resources.
>Radio Shack sells a 9 volt NiCad for about $10.  You can get a cheap Ever-
>Ready from the local grocery store for under $1.00 which will easily (in
>my experience--and I have three smoke detectors at home) last a year or
>longer.  This means you'll need to use the NiCad for at least 10 years to
>even break even--not to mention the hassles of recharging (what will you
>do with the detector while the NiCad recharges for 14 hours?) and the fact
>that the NiCad may not last 10 years.

You pay too much for 9V NiCd's.  I find them for about $2.50.  But a more
important point:  NICADS LOOSE CHARGE RATHER QUICKLY.  YOU WOULD HAVE TO
RECHARGE THEM ABOUT EVERY MONTH OR TWO IN THAT APPLICATION.  YOU WOULD BE
MORE INCLINED TO FORGET ABOUT THEM AND BE WITHOUT PROTECTION!!  (imho.)


I use alkalines because I trust them.  Cost in an application like that
should not be a consideration.