<p>This paper details the design, development and evaluation of a 3D printed, rechargeable, Ag-AgCl electrode to measure Self-Potential (SP) in laboratory experiments. The challenge was to make a small, cheap, robust and stable electrode that could be used in a wide range of applications. The new electrodes are shown to offer comparable performance with custom-machined laboratory standards, and the inclusion of 3D printing (both Fused Filament Fabrication (FFF) and stereolithography (SLA)) makes them more versatile and less expensive than laboratory standards. The devices have been used in both low-pressure experiments using beadpacks, and high-pressure experiments using natural rock samples. Designs are included for both male and female connections to laboratory equipment.</p>