> Thanks to both of you for your quick response.
>
> Is it reasonable for this battery to die within three and half years? >
> I don't recall replacing any such battery in our old house and we
> stayed there for 6 years.
>
> Thanks again for your help.
>
>
Thanks everyone for the good advice. Our battery just went out after a full 10 years and 8 months! The unit has been waking us up every 4 hours ARG! to complain of the battery failure. It's a Casil 12v 4AH manufactured by Chee Yuen Industrial Co. Ltd.
----which just goes to show that you CAN get quality from China LOL