Smoke Detectors without batteries (wired) - is this okay?

Question

I have been remodeling a triplex. The middle unit has smoke detectors without batteries. There were batteries installed in them, but they were just against plastic, there is no connection to the battery. They were all wired in as shown in the photo's. The building is built in 1998. The other two units had a different style of smoke detector that had wire and battery. Photo here: http://1drv.ms/1UUdfkT - Is this a normal type detector or something odd that should be removed?

Thank You!

Zach Schwarzmiller · Answer

Okay - cool. Thank You! Adam B.

Steve Babiak · Answer

The photos look very similar to the units in the house where I live. Hard wired and battery back up in the event of power failure. Looking at the third photo that shows the guts of the unit, the battery terminals should be in the photo just above the green LED; the battery compartment would be to the right of the battery terminals, and the battery installs by rotating a plastic part that looks to be missing. So my first guess is that something isn't right. But it appears that you have a plain 9120, and the 9120B is the one with a battery backup that I use. See link:

http://www.brkelectronics.com/pdfs/2009/04/08/5954...

Now, this unit is from Aug 2007 from photo number two, so eight years old now. Those units are rated for a ten year life expectancy at which point you toss the old unit and replace with a new one. So you have just under two years to go. If you buy the BRK or First Alert (I get those brands at Lowes), the new one won't require any rewiring, but the base attached to the wall or ceiling might have to be changed out if it does not exactly match the base on the new replacement. And you can get a combo CO and smoke unit in the same brands where no rewiring would be needed. And you can get one with battery backup that would not need rewiring either. Just use the existing connector that is already wired when you go to replace.

Carlos Enriquez · Answer

Not only smoke detectors but carbon monoxide as well (10 year battery).

Adam Bartomeo · Answer

You will have to check your local codes. It should tell you what kind of smoke detectors are approved and where they should be located. They just passed a code here where you have to install throw away smoke detectors that are only battery operated. The batteries die after 10 years and there isn't a way to replace them.

Russ Draper · Answer

Depends on state and code, around here smoke detectors in bedrooms are required I believe and they have to have a battery.  Common areas can be hardwired I think.  One of my properties has both, hardwired with 9v batteries as backup (it even speaks aloud if a battery is low).