I ordered the set on 23.10.2011 and two of them mounted to speedy arrival. Last week, suddenly began the first smoke detector to beep once per minute! Spannungsmesung on the developed ULTRALIFE battery: Only 8.64 volts. Although up to 10 years period of operation is true, but still I feel cheated because: Without Lupe unreadable imprint on battery: 10172, thus probably 02/2017 - 10 years ??? With a standard battery of smoke detectors would probably loose works for a year!
So now I have the voltage of the battery of the first smoke detector measured: 9,14V, goes like this. Then I have the voltage of the battery of the third not yet mounted smoke detector measured: 0.72V, so empty !!
How beautiful would be the world if there were not so many idiots who have nothing in the way to cheat than one !!!
