BEST NOTE BY FIREFIGHTERS ENGLISH AND GERMAN AND TESTS CONFIRM

The comment is inappropriate to 1 star: a detector cell has an expiration date usually 5 years, there change the detector which is inefficient and it is useless to change the battery or put a long-life battery, as this sensor is no longer reliable, so it should be changed for a responsible insurance outlet.
The maximum duration of operation of a sensor cell is 10 years (that is an electronic component)
In all cases, it will change the maximum detector every ten years (I do not see people change the cell only because it takes the desoldering, etc .....).
This detector has the guarantee cell 10 and a battery life of 10 years, so it's perfect and in addition has a great rate: it is the longest and like all the others, unfortunately, it will take after the throw.
In addition it is the model recommended by the English and the best firefighters in the German test, both well ahead in terms of the particular fire protection, with respect to our country.
I want to clarify that the instructions are in french and a download.