I designed this battery holder to fit into a 25mm tube. Originally it was designed to be used as power source for a light saber
But it can be used for any circular gadgets to fit 3 AAA batteries (4,5V)
In order to assamble it, I used 15mm springs that I bent apart to fit the holes an directly connect the + and - ends of the batteries.
Thanks to @stritti for suggesting the standalone upload of this battery holder.
The author marked this model as their own original creation.