Re: Smoke detector and rechargeable 9V battery?

[stu@xxxxxxxxxx]

Robert L Bass wrote:
> > Isn't a Lithium cell more potent thanan alkaline?
>
> Lithium cells have a different discharge gradient from alkaline cells.  When a typical alkaline cell reaches the point where the
> detector starts to signal a low battery condition, there is a predictable remaining life in the cell.  IOW, it will continue to
> function for a sufficient period.  IIRC, lithium cells degrade at a fairly steady rate and then drop off sharply.  Assuming it's
> lithium cells and not some other type of rechargeable cell that this applies to, that would make them unacceptable for use in many
> smokes.
>
> --
>
> Regards,
> Robert L Bass
>


Robert,

Thanks, finally a substantive answer.


The question still remains open however..

What is the time period that is required/needed to give ample beep
warnings to replace or recharge?

>From Wikipedia:

"Some detectors are also being sold with a lithium battery that can run
for about 7 to 10 years, though this might actually make it less likely
for people to change batteries since their replacement is needed so
infrequently. By that time, the whole detector should be replaced.
Though relatively expensive, user-replaceable 9 volt lithium batteries
(in the same configuration as the common alkaline ones) are also
available. They should only be used in a fairly new detector."


I wonder if the lithium detectors have a different warning voltage?