Have you lost the little aluminum battery cap for your Apple wireless keyboard? Fret not! With about 6 minutes of 3D printing, some sharp pliers/wire cutters and a basic, normal-size paperclip, you can get your keyboard working again! :)I modeled this for a friend who lost theirs.

The aluminum cap on these keyboards not only holds the batteries in, but acts as part of the circuit for the keyboard to function as is metal and allows the ground to pass from the end of the battery into the keyboard's aluminum case.

As plastic does not conduct electricity, the paper clip is used to transfer that power ground through the paperclip from the battery to the chassis instead! Stick an unfolded paperclip in the hole in the side of the cap as far as it will go and carefully bend it tightly in the slot along the one side and then around and over the top. Leave the folded part on the top bowed out a bit as this needs to make contact with the battery. You'll need to trim off some of the paper clip to make it fit, hence the pliers / wire cutters. (You can see what I mean in my pics).

Took me 2 tries to print one that fit well enough. I find if I tighten the cap TOO much the contact is broken, so might take you a little bit of trial and error but...hey...once it's sorted you have your $70-when-new keyboard working again! :)

Hope this is useful for some people! Yes, I know replacement legitimate aluminum caps are available online in places like Amazon and Aliexpress...but the cheapest ones on Ali for $4 would take forever to arrive with shipping (likely over a month)...and the cheapest on Amazon seems to be like $10! SOOO...this is a cheaper and much faster and effective solution! :D

Thanks very much and feel free to toss me a little tip if you are so inclined and you find anything of mine useful! ^_^