Back of the badge:
A York Hackspace badge was designed (end of 2014 ish) for events where we may be able to sell badges to the public and teach them how to solder them together.
The designs are available on github here
Each badge requires one flashing colour changing LED, one CR20xx battery holder and one battery either CR2032 or CR2025 (prefer 2032). The only tool required will be a soldering iron and of course you will need some solder. For a soldering workshop, it may be a good idea to have desoldering tools handy too.
The LED should be soldered on to the front and the battery holder soldered to the back.
The badge has holes at the top for string to go through to hold it to a button, zip, keyring, etc.
The first batch (which can be identified by the code JWV142066) has a design flaw. The polarity is incorrect. If assembled according to the documentation, the battery must be inserted upside down. Alternatively, the LED or the battery holder can be reversed and the badge will work with the battery correctly inserted.