----- Original Message ----- > From: b...@theworld.com > On January 4, 2021 at 21:19 valdis.kletni...@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 j...@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
