On Sun, 14 Dec 2014 20:44:53 -0500, "Bobby R."
wrote:

Suggestions for battery operated smoke alarms.

I saw recently that alarms now come with a sealed lithium battery,
said to last 10 years. Detectors should be replace every ten years.

"...long-life lithium battery that is warranted by the manufacture to
ensure a decade's worth of protection! This effectively translates to
ten years of constant and undisturbed coverage."

YMMV