How to Convert a Gas Motor to a DC Motor

Find a lawn mower deck that has had the gas engine removed. Lawn mower repair shops will have these on hand, and the owners are often more than willing to get them off their hands. If you want to convert a mower that still has the gas engine attached, consult the owner's manual as to the specific steps for removal, as the process can vary significantly, depending on the manufacturer.

Purchase an electric motor with one-third the horsepower of the gas engine that would be compatible with the mower deck. Several manufacturers make electric engines designed for use with lawnmowers. You'll also need two circuit breakers and two batteries. DC circuit breakers are available at marine supply shops.

Set the electric engine into the hole in the middle of the mower deck and attach it using the hardware provided. Using scrap lumber and a saw, make a small box to hold the batteries, with L-brackets holding the sides to the base. Run a tie-down strap around the case and through a bracket on the motor mount to hold the box in place.

Cut a piece of scrap lumber that will fit across the handle area on your lawn mower. Drill holes in the wood to allow mounting screws for your ammeter and voltmeter, as well as your power switch for the motor. Run wires from the back of the meters and the power switch to the batteries, and then wire the battery terminals to the engine terminals.

Test the motor's operation by turning the switch on. When it's working, disconnect the wires going to the engine from the battery and install the blade. If you've chosen a design made for a lawn mower, you should have a shaft with threading extending down through the deck, ready for you to screw the blade on. Attach the blade with a hex nut (unless it came with different hardware), tighten into place with a wrench, and your mower is ready.