9v Battery Noise Preamp Fizz Thingy

[Delberthot]

I've just plugged my Stingray in tonight and it sounded like the battery was on it's way out so I changed the battery to a Duracell Industrial which is what I always use in my Musicman basses and it began emitting a really strange noise.

Almost like the electronic equivalent of someone blowing a raspberry. I put the original Aerocell battery in a everything is fine again. I've checked the battery which has a date of March 2020 and it's still reading 9.16v. I've tried a regular Duracell that I had lying around and it works fine as well. The original battery that I took out has a reading of 8.67v

Any ideas What could be causing this? In my 20 odd years of owning active basses I've never had this before

[itu]

Basic voltage should be checked with some load to get real results. I suppose this battery has met its end even before it has started its work.