m36

thingiverse

I needed a cheap portable AC power supply similar to the DeWalt power station, which isn't cheap. I have Milwaukee tools, so I made one using 36-volt to 12-volt golf cart regulators. Assuming you already have Milwaukee M18 drills/batteries, you could print this and with less than $50 in parts have a 12-volt outlet capable of running a 120-volt inverter. I tested the run time, and with a 120-volt, 120-watt load running off a cheap inverter it runs for about one hour exactly. WARNING: There is no under-voltage protection in the current design, and the batteries will run beyond their safe discharge level if left unattended. So be sure to remove a battery when not in use or when one of the gauges shows a low level. Build Instructions Smash the end of a piece of 14-gauge solid wire (Romex) with a hammer against a smooth surface (cement floor). Leave enough wire to route through the paths to the outlet plug. Push the unsmashed wire into the wire channels in the base part with a flat-blade screwdriver, or something similar. I used the uninsulated piece of wire from the Romex for the jumper between the two batteries. Smash both ends of a piece long enough to fit before inserting into the wire channel. You can trim off the excess if there is too much exposed. Route all wires and make all connections before bolting the converters on. There isn't much space for wire connections in the DC outlet area in this version, so soldering and heat shrink were used to make the connections. B.O.M. 1. 12-volt outlet (came in a 2-pack), one with a copper main post is highly recommended 3. 10-amp, 36-volt to 12-volt converters (commonly used in golf carts) 2 Foot approximately of Romex 14/2 some bolts/screws (exact size isn't critical) Updates in progress Clean up 3D model Add a handle and a means of attaching inverters Make the area where the outlet is larger for easier wiring and add some higher-ampere connector options as the "lighter outlet" isn't meant for high amperage Note that pictures are of V1, and that V2 is as yet untested. Update 3-18-19: Printed lower portion of V2, and the battery is far easier to insert and remove.