I just discovered that BRK either is planning on releasing or has already released a new line of smoke detectors that start in “SM6” or “SM6W” depending on whether they’re DC or AC/DC respectively, but what mainly caught my eye was the fact that on the non-10-year battery models is a feature called “SoftCue”, which they claim makes the low battery chirp less annoying. I gotta say, as someone who hates 10-year battery detectors because they’re useless once outdated (to collectors of course), I love this approach to avoiding people pulling the battery out or forgetting to change it (I also love the fact that BRK offers non-10-year battery models with this line, since they didn’t when it comes to their “Precision Detection”-series DC units). Needless to say, I do believe I’ll be going with these for my replacement projects from now on solely because of that feature, heh (since before my only options were to give in & go with BRK’s “Precision Detection”-series units, which did not have a non-10-year battery DC unit as said before, or to go with Kidde instead, who still sell non-10-year battery DC detectors but who’s products are also of questionable quality, not to mention all the recalls they’ve issued over the years).
SM601 Battery Powered Smoke Alarm
SM610 10-year Sealed Battery Smoke Alarm
SM6W01 Hardwire Smoke Alarm w/ Battery Backup
SM6W10 Hardwired Smoke Alarm with 10-year Battery Backup
The manuals were posted on “August 6, 2026.” Has someone discovered time travel?
The specifications of these devices don’t say anything about the frequency, but given that the sound level “Meets or exceeds current UL standards of 85 dB at 10 feet (3 meters)” it is probably not 520 Hz, since the PLACE smoke alarms only output 79 dBA.
Oh? Didn’t even notice that. That’s odd.
Well I didn’t say anything about them having 520 Hz-capable horns either, but that is a good idea considering how effective it is in waking sleeping individuals (not to mention being much easier on the ears due to not being so shrill, heh).
I know, but it would certainly be significant if it was.
As a side note, I noticed that the SM6W01 will be replacing the SM100V-AC, which is a talking smoke alarm (demo here). The manual for the SM6W01 doesn’t say anything about it talking, so that might be a lost feature.
The SM6W01 is also replacing the SM300-AC, which is a dual ionization and photoelectric sensor, and the SM6W10 is replacing the SM105-AC, which is an ionization smoke alarm. All of the new smoke alarms are photoelectric, so First Alert might be finally discontinuing their ionization technology.
Yeah.
Oh? Hmm…
Oh? Neat. About time ionization-only started being phased out in the residential side of things as well given how unreliable it often is. Also nice that BRK is seemingly the first one to do so: goes to show that they truly are always a step ahead of everyone else when it comes to innovative life safety products! (much like Edwards in fact, heh)
I don’t think Kidde is offering ionization smoke alarms in their new line either, and I’m not sure if Gentex ever did.
Ionization smoke alarms listed for the 8th edition of UL 217 are supposedly fine, at least according to this video. I’m wondering if there is some kind of new UL requirement in the 9th or 10th edition or a new NRC regulation prohibiting the use of radioactive materials in smoke alarms.
One thing about the new line (and other new lines of smoke alarms) I don’t understand is the need to make separate models for battery-only and hardwired devices instead of making all devices hardwired but including a mechanism to disable/remove the wires if the unit is intended to be used with only a battery. That would mean fewer SKUs, and it would probably reduce the instances where a homeowner replaces their hardwired and interconnected smoke alarms with battery-only alarms.
Oh? Alright, huh…
Sure, but is there really anything you can do about the basic sensor design that will somehow allow it to detect the kinds of fires ionization detectors nearly-always “sleep” through? (which is why they’re generally unreliable)
That would make sense, but I’m not sure it’s really possible to do so, since each kind is specifically designed for their particular power source(s) (I believe people have even reported AC/DC smoke detectors being “damaged” by only running them on battery).
Probably not, which is where the need for the internal chip to recognize complex fire patterns. This probably has the advantage of detecting both flaming and smoldering fires as opposed to photoelectric sensors only detecting smoldering fires, but I imagine a flaming fire will also quickly trigger a heat alarm or sprinkler head, which is much less prone to false alarms. As far as I know, only 2 states require new single-family homes to have sprinklers (California and Maryland), but they do not require sprinklers in additions/alterations to existing homes, and even when sprinklers are required, I don’t think there is any requirement for the sprinkler system to activate the smoke alarms. Also, as far as I know, Kidde is the only brand that allows external initiating devices such as pull stations and flow switches to initiate smoke alarms, so it is difficult to implement such protection in a home.
I’m not sure if this conflicts with UL’s requirements, but there is a very simple way to construct a hybrid device with a 10-year battery: make the sensor and alarm entirely battery-powered, and connect the AC power to the green LED and to a circuit that causes the piezo to repeatedly chirp after the battery is fully depleted. Everything except the end-of-life chirp can be designed for battery operation only, and I doubt switching the piezo to FWR power from the AC source will cause problems given that most audible notification appliances work on FWR. The sensor won’t work anymore after the battery is fully depleted, but by that point, the horn will be constantly chirping and the device should no longer be used.
This won’t work for smoke alarms with replaceable batteries, but those are generally a bad idea anyway. There might be some exceptional situations where they are needed, but those should be ordered via special order from the manufacturer instead of being sold at retail stores where unknowing customers are prone to purchasing them.
This is not to mention that if AC-powered smoke alarms are actually being damaged when they lose their AC power, then there is more to be concerned about than the need to create more SKUs. Operating on battery power is an essential function of any smoke alarm to ensure reliability, so this seems like it would not be acceptable to UL. Do you know what this “damage” actually resulted in?
Kidde is the only brand that provides a listed module for this function. While it’s outside their UL listings, USI and First Alert alarms can work with the 9V output of a Kidde SM120X. (Gentex is the odd one out since “new style” Gentex interconnect directly cadences the horn; you won’t break the alarm if you use a SM120X to apply 9V to a “new style” Gentex interconnect line, but you will get a continuous tone instead of Temporal 3.)
I do agree that it’s unfortunate that other manufacturers don’t provide the SM120X’s 9V-out function in their relay modules, or better yet, provide a power module that can ride herd on a backup battery in addition to AC power.
You forgot “comes from” at the end there didn’t you, heh.
Yeah: keyword “probably”, even though pretty much no matter what you do ionization & photoelectric detectors will always have very specific kinds of fires they’re the quickest at sensing.
Now that is just dumb.
As far as I know the SM120X is just Kidde’s residential detector relay like those made by FireX, First Alert, & USI Electric, & that it has no reverse polarity function: no clue where you got the latter from since I’m fairly certain that “relaying” is its only intended function.
Honestly kinda makes having the detector be connected to AC completely pointless if the only thing it’s actually running off of is the battery though.
I beg to differ, & so does BRK/First Alert going by their latest line of detectors having that “SoftCue” battery change signal, as I outlined at the start of this topic.
I guess so.
I’m not sure, I just swear once reading that you’re not supposed to run AC/DC detectors off DC power only (which makes sense as that’s not what they’re designed to do).
The module would probably need an integral sounder or something similar to ensure that low batteries are properly annunciated. Depending on component costs, the best solution might be to produce heat and smoke alarm models with external inputs directly on them to allow for this connection without requiring an extra device.
The manual explains that pull stations and heat detectors can be interconnected with the smoke alarms using it.
AC power is required by the IBC, probably to avoid a situation where a battery is depleted while the home is unoccupied and the dead battery goes unnoticed when the home becomes occupied again. I’m not sure what UL requires regarding power sources.
I phrased that poorly; I think battery-only smoke alarms with replaceable batteries are a bad idea, since an occupant could very easily remove the batteries to eliminate unwanted alarms, and there would be no resulting trouble signal. If there is some other way the trouble is indicated (e.g. if a wireless network of smoke alarms is supervised by a single hardwired unit), then this is no longer an issue, but this line of smoke alarms does not appear to support wireless interconnect.
It’s not good to connect a smoke alarm to DC power only when AC power is available because of the issues of the battery being depleted, so it’s possible that the warning was about that.
It’s not reverse polarity – the SM120X has a low-current, non-isolated 9VDC output from its AC supply that can be connected to the interconnect line via a dry contact device to permit that device to set off the smoke alarms.
If you have battery back up in it, then yeah, that’d be needed. I think UL 217 would permit you to have an external input on a smoke alarm, but for some reason, nobody wants to go there…
(this is doubly unfortunate since LF horns are 24V only devices, while UL985 panels are 12V units.)
That might make sense, yeah.
Oh? Huh, surprised that’s not a more widely-advertised feature of it (which is why I didn’t know about it).
I guess that makes sense.
I guess so, but as you can see BRK/First Alert is for one trying to do something about the problem (something different from other manufacturers no less).
Maybe, yeah.
Well that was the best way I could think to put it as I believe that’s what Gentex calls that function on some of their units.
What is BRK/First Alert doing differently? Almost every manufacturer offers sealed 10-year battery smoke alarms now because many jurisdictions require them when smoke alarms are battery-only.
You want to know what they’re doing differently? I’ll tell you what they’re doing differently (though have you not seen me mention the following feature twice already because of how much I love it?): they are simply making the low battery signal on detectors with traditional replaceable batteries much less annoying with their new “SoftCue” feature, rather than doing what every other company does by having the battery last 10 years (which as I said I love since it means the detector hopefully shouldn’t be rendered completely useless once it’s time to replace it, which up until now collectors could nearly-always count on & didn’t have to worry about since 10-year battery detectors were not common. Yes at the end of the day I know it’s more about actual life safety than collectors, but perhaps BRK/First Alert’s approach will benefit both sides).