Vintage Simmons Drums (UK) Users Group

While I have my SDS9 apart for a potentiometer replacement, I figured I'd go and replace the battery.

I did a bunch of searching here and it seems there may be differing opinions on what type of battery to replace the original with.

I posted up a picture of my battery in a album called Realm Steel.
I don't know how to link the album or picture to this post.

When I Google the NC-M 100 it comes back with NiMH batteries, but I've seen comments about using NiCd.

My battery is putting out 0.775v. Should it be 3.7v?

Is there any reason I need to use a battery with 3 pins?
Looking at the circuit board, the positives are on the same trace.

Has anyone tried putting in a battery holder and used something like a CR2032 button cell type?

Lastly, anyone have a schematic I could have? I didn't see one in the DL's section.

There is a lot there, but when I get into something I want to know the "why's" and not just the "do's".

Thanks,

Rich