Well, this is kind of a semi-answer, and a kind of a back to the top post.
For the back to the top bit, someone here may have tried it before, and can add the details of their experience.
But as a semi answer, my response is “maybe it will“ and then again “maybe it won’t” double speak.



How’s that for commitment!
For more detail, you can probably get other batteries to fit the tray, but the height and top clamp design are more specific to the Optima.
If you have a battery that fits otherwise, but it’s a little too tall, some small spacers between the top clamp and their brackets would probably take care of that.
If the battery is slightly shorter than an Optima, you can probably add a soft spacer, perhaps of plastic or of foam.
If the top of the other battery is perfectly flat with plenty of room for support, the top clamp will probably fit right down over it and hold it tight.
But initially, the Optima battery tray is designed fairly tightly around the standard Optima battery size and shape.
Hopefully some members here have tried and found alternatives, but I will also check with the guys at the shop and see if anyone here has ever played around with different batteries.
It’s bound to have come up before, after all these years, but I don’t remember ever hearing about any other attempts.
Let you know what I find out.