Unfortunately, "Stay away"

Have these smoke detectors bought 7 weeks and delivery, price and installation were ok. But unfortunately, these detectors have a dynamic life of its own. For more than a week both beeping irregularly with a single beep. So about 2-3 times in 24 hours. This is unpleasant, especially at night in the bedroom, to stand on one square to the bed. The batteries are good. Quality batteries were present in the delivery. Have already expensive new batteries tried, but the beeping always comes back irregular and annoying uncommonly.
Too bad, because the detectors are optically made a good impression and the installation was easy. But that's not portable.
Let's see how Amazon responds to this problem.