I'm about to have that very same WTF moment.
I just finished replacing a few of the failing keys on a very "used" AN1x I picked up and as soon as I had it all back together I got the Battery Low message. Bah.
I couldn't find a CR2450y anywhere, either so I'm about to see how it fits tonight.
Will report on my progress.
--- In AN1x-list@yahoogroups.com, "ras_mynameisnottaken" <letterzbox@...> wrote:
>
> Hi Folks,
>
> After 12 years of service, the lithium battery finally started to die. So I got a replacement battery model CR 2450n.
>
> The battery looks identical except I noticed that it doesn't fit in quite as well as the original. The original in my AN1x was a CR 2450y. I could not find a 2450y, perhaps Yamaha carries these?
>
> The diameter seems the same between the two, but one must be slightly thicker or something as I was unable to get the clip that olds the battery in place to click fully back on the way the y model battery did.
>
> This doesn't seem to affect the function of the battery at all and its still pretty secure as it takes a jeweler's screwdriver to pop-out, just avoid knocking around the synth incase the battery were to pop out (this is always good advice anyway).
>
> Just thought I would put this on the record for future battery swappers that have the WTF moment like I did :)
>