I’ve been getting some email about the RTC Plugs not retaining their clock. It turns out that there is a problem:
The center contact of the battery “holder” is the PCB itself, and being gold-plated, I thought it’d be best to keep it as is.
The problem is that the solder mask layer can be slightly thicker than the gold-plated pad, causing the battery to not make contact – despite the pressure of the metal clip.
This can be fixed by adding a small dab of solder:
This will cause the coin cell to press more against both contacts, so a good connection is virtually guaranteed.
Needless to say, I’ve updated all RTC plugs here and will ship this improved version from now on.