Lead acid batteries come with a useful protector plastic cover for their terminals. These tiny parts can be lost very easily.
I made a replica for them.
The slit is 6.5*0.8mm, quite tight fit, won't fall of easily. 3D printers are not too accurate in such small dimensions, on your printer it might require some adjusting with a pliers on the terminal to fit more smoothly, or a few percent upscaling.
The single pole variant needs only 8 minutes to print.
I made a variant for both poles connected with a string. This fits lead-acid batteries up to 12V 12Ah.
Fusion360 project included as well.
The author marked this model as their own original creation.