----- Original Message -----
From: bzs@theworld.com
On January 4, 2021 at 21:19 valdis.kletnieks@vt.edu (Valdis Klētnieks) wrote:
First, that means your smoke alarm batteries run down faster, which is a major issue.
That's the sort of argument I label "all sign, no magnitude".
How much faster? If it took one minute of battery life off a 10 year battery would that be a problem? 30 minutes?
Well, let's address that. Last time I looked, consumer residential smoke detectors were still running off 9V alkaline batteries, which are expected to run the device for 6 months of 1/99 duty cycle (or less, probably *way* less). An Energizer 9v is rated for 8.4VDC in the very general vicinity of 500mAh.
How does that compare to other factors like ambient temperature which also affects battery life but we mostly consider "in the noise"?
A lot. Increasing the alert count from the 1 or 2 it probably is on most smoke alarms to 2 or 3 a *week*, with LOUD analog speaker alert playback is going to change that duty cycle, probably, to something like 10/90. [ All numbers pulled out of my butt for illustration, but probably within half an order of magnitude. ]
Could we make the battery just a little more powerful? How much power would a bit of circuitry waiting for a "turn on! there's a new message coming in!" need?
Well, parsing for EAS on the receiver is going to make its drain non-trivial, too, I think. But there are "increasing the battery replacement frequency" problems *and* "increasing the battery capacity and hence price, not to mention general availability" problems balancing that out. Any way you play it, it has to be an optional model, not a general takeover of the field, I suspect, or the "well we just won't bother anymore" factor takes over. Cheers, -- jra -- Jay R. Ashworth Baylink jra@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://www.bcp38.info 2000 Land Rover DII St Petersburg FL USA BCP38: Ask For It By Name! +1 727 647 1274