Car‑Plug Voltmeter: Battery Health Checker

Hi,

A few weeks ago, the battery in my old car suddenly died. The car and battery are both quite old, I don’t drive very often, and when I do it’s usually only short distances. That’s probably why the battery failed. During winter everything still seemed fine, and then one day the car simply wouldn’t start.

The battery had dropped to a deep‑discharged state at around 9.6 V. I bought a new one, but I wanted a simple way to keep an eye on the battery’s charge level and overall health. So, using some spare parts I had lying around, I built this car‑plug voltmeter. I designed the case, soldered everything together, and now with a single press of a button I can instantly check the battery voltage.

Print Settings:
Layer height: 0.25 mm (0.4 mm nozzle)
Perimeters: 4
Infill: 10% gyroid
Solid layers: 3 top and 3 bottom
Supports: yes
Print orientation: as shown in the pictures
Material: PLA

Materials:
- printed case parts
- old car battery plug
- a push button
- some wires
- 2 screws M3x12 mm
- 3-digit 7-segment voltmeter display (7-segment display size: 22,60 x 14,00, 2x 3,00 mm holes)
used module: https://www.roboter-bausatz.de/p/mini-voltmeter-digital-mit-led-anzeige

Happy printing & Make the world a better place, one print at a time.