Weazel, glad you're OK. Hope the damage isn't too great and I hope you resume posting soon. (Without the unnecessary name calling

)
Consider buying one or two detectors that are "hard-wired" into the electrical system. Think of it as "belt and suspenders" type engineering.
Yah, the electrical system may fail... but then you have the battery operated models. Batteries may fail but then you have the "hard-wired" back-ups. The dual mode capability improves your odds of getting a warning.
Doesn't cost that much either.