Rugged 12V Battery Box for 9Ah SLA / 12Ah LiFePO4 (151x65x100) - Parametric, Captive M4 Nuts

A rugged, parametric enclosure for 12 V 9 Ah SLA or 12 Ah LiFePO4 batteries (151 x 65 x 100 mm). It has a front panel for a 29 mm level gauge and a rocker switch, plus a strain-relief cable clamp. Every screw goes into a captive M4 hex nut, so there are no threads in plastic. Prints without supports.

Print orientation is already set in the STL files: body upright, lid top face down, clamp groove up.

Use 4 perimeters (walls) so the 3 mm walls and the nut pockets come out solid.

No supports needed. All overhangs are 45 deg chamfers or short bridges: nut pocket ceilings 7.2 mm, vent and floor groove tops 3 mm, switch cut-out top 21 mm. If your slicer's auto-supports are on, it will put supports inside the nut pockets and on the inner front wall. Leave supports off.

The top edge of the dia. 29 mm gauge hole may sag slightly. The gauge flange covers it.

Filament used (PrusaSlicer 2.7, 0.4 mm nozzle, 0.2 mm layers, 4 perimeters, 25 % gyroid, PETG): body ~334 g, lid ~55 g, clamp ~2 g, ~392 g total.

Bill of Materials (EN)

Qty Part Notes

1 Printed body (battery_box_body.stl) PETG, ~334 g

1 Printed lid (battery_box_lid.stl) PETG, ~55 g

1 Printed cable clamp (battery_box_clamp.stl) PETG, ~2 g

4 M4 x 16 screw (lid) Any head type. M4x12 to M4x25 also fit

2 M4 x 20 screw (cable clamp) M4x20 to M4x30 also fit

6 M4 hex nut, DIN 934 / ISO 4032 (7 mm across flats) Pressed in from below

1 Battery level gauge, dia. 29 mm panel mount, nut-mounted Measure the nut outer diameter (gauge_nut_d)

1 Waterproof rocker switch, 21 x 15 mm panel cut-out Check the cut-out (sw_w, sw_h)

• Cable, 2 x 1.5 mm2 H05RN-F (~8 mm OD) Measure the OD (cable_d)
• Silicone sealant For the cable hole

1 12 V battery, 151 x 65 x 100 mm (9 Ah SLA / 12 Ah LiFePO4) Not included

(rec.) Inline fuse + holder No holder in the design. Recommended for safety