We have 2 Norelco smoke detector in the house. Early this morning, one of them began issuing short "battery is low" beeps every 5 minutes. The batteries for these detectors are 9v. I replaced the battery in the one that was beeping with a Gettop (Chinese) battery that I've never used for anything before. After doing so, the detector started issuing beeps about every minute. Thinking they battery must be run down or defective, I measured the voltage. To my surprise, it was 10v, not 9. I then checked to see if the contacts in the detector had become corroded. They hadn't. I then replaced the Gettop with a Duracell 9v, and the detector no longer beeped/worked perfectly.
Thinking perhaps that detector might have become faulty, I tried the Gettop in the other detector downstairs. Same result; immediately started issuing short beeps at 1 minute intervals.
Why is the Gettop unusable in these smoke detectors? Is it because they're intolerant of batteries putting out 10v (even though it says it's a 9v on the label)? Has anyone else had a similar problem with Gettop batteries?