Deere Gator Converted To Electric

Deere Gator Converted To Electric ENERGY Miscellaneous After a field fire burned up his Deere Gator Brian Laine could have junked the 25-year-old machine Instead he decided to turn it into something new     “A few years earlier I bought a crate of lithium-iron-phosphate batteries at reduced cost on Craigslist from someone’s failed EV project ” says Laine “The old engine was 16 hp so I figured a 10kW power plant would give me roughly equivalent horsepower 13 to 14 hp Given the electric motor’s flat torque curve I expected it would match or outperform the original ”     After stripping out fire-damaged parts Laine removed the Gator’s original drive train with forward/reverse gearbox     “I shopped some sites and found a supplier that could sell many of the parts needed: the DC motor controller gearbox pedal and even an instrument cluster ” says Laine     After getting the rough dimensions of the parts he calculated room for about 22 batteries He placed 16 behind the motor and three under each seat in place of the old fuel tank and radiator The batteries he had purchased were 3 2 volts producing about 72 volts in total     Laine estimated the project would take a few weeks once the parts arrived He ended up working on it on and off for about 6 months There were some things he hadn’t anticipated     “Talking to the motor manufacturer I was told I should have a BMS or battery management system to help protect the batteries and add safety to the design ” says Laine     The BMS connects to each cell and balances them as needed It also monitors voltage to make sure the batteries don’t get overcharged overdischarged or overheated and will power down if needed     Laine’s first challenge was how to couple the gearbox with its differential and CV-joint axles to the Gator’s splined shafts on the forward drive axle Limited space on the driver’s side required modifications He coupled half of the original splined adapter from the Gator to the shell of the new CV joint However when he spun the axle it bound slightly He ended up replacing it with a Lovejoy coupling to provide needed flexibility and some cushioning to the drive This required cutting drilling and tapping the Lovejoy shell to attach it to one side then machining the splined Deere connector to size and cutting a keyway in it for the other half     “On the passenger side I had plenty of room for the axle and CV joint ” says Laine “I cut back the provided axle and machined a spacer to adapt it to the Gator’s splined part I turned a piece of scrap into a bushing and coupled them together with a 3/16-in diameter roll pin holding it together ”     The original gearbox had brakes built in With no room for brakes on the forward drive axles Laine installed mechanical disc brakes on the rear axles with the option of installing dual brake pedals for independent braking     “I made the discs from scrap steel and added go-cart brake calipers ” says Laine “I cut the Gator’s splined hub adapters in half and machined them to accommodate the discs before welding them together If the new roller chain ever needs adjusting I may have to shave down the spacer blocks or disks not ideal ”     The motor controller converts battery DC power to AC needed by the motor to control speed and current It also provides regenerative braking back to the batteries     Laine installed an onboard charger that charges at a rate of about 12 amps automatically stopping when fully charged     A DC converter takes 72-volt battery power and provides 12-volt DC at 25 amps to run the bed lifting actuator lights and auxiliary output plug on the rear of the machine for use with a sprayer     “I added solid-state fuses to each battery bank ” says Laine “The fuse manufacturer wanted something like $70 each for fuse mounts but I drew them up on CAD and 3D printed them for cheap ”     Laine also fabricated aluminum panels to hinge down with the seats to cover the batteries He used old road signs purchased at a swap meet     “I needed to connect all 22 cells in parallel so I made copper busbars with a slot on one end so any bar can be used to connect batteries end-to-end or side-to-side ” says Laine     Along with the new electric drive Laine refurbished and repainted the machine     The new eGator hums along at 30 mph Based on use to date he estimates about 3 hrs run time Upgrading to newer batteries would likely double that or more     When finished the total cost for conversion parts was about $2 000 thanks to the low-cost batteries While not cheap Laine compares it to buying a new Gator for $20 000     As with several other projects Laine has detailed the entire conversion process with many pictures on his website     Contact: FARM SHOW Followup Brian Laine 7921 Wade Rd Arlington Wash 98223 ph 425-879-2890; brianlaine@aol com; www lainefamily com

To read the rest of this story, download this issue below or click here to register with your account number.