[AmpEater] spent the summer converting yard equipment from internal combustion to electric power. The conversions run from a relatively tame Wheel Horse, to an insane Cub Cadet. The Wheel Horse lost its Kohler engine in favor of a hydraulic pump motor from a crown forklift. 48 volt power is supplied by MK lead acid gel cells. An Alltrax 300 amp controller keeps this horse reigned in.
On his Reddit thread, [AmpEater] says he is especially proud of his Cub Cadet zero turn ride on mower. For those who aren’t up on lawn implement terminology, a “zero turn” means a mower with zero turning radius. Zero turn mowers use two large wheels and tank style steering to turn within their own radius. We bet this style mower would also make a pretty good robot conversion, however [AmpEater’s] zero turn is still setup for cutting the grass.
After pulling the V-twin motor the 48 volt Motenergy ME-1004 was put in place. Batteries are 3 x Enerdel 48V 33 amp hour lithium ion packs. The packs are wired in series to provide 144V nominal. Right about here is where our brain started to melt. A 48V motor on 144V has to mean magic smoke, right? This is where the motor controller magic comes in.
[AmpEater] used Evnetics soliton-jr motor controller. The controller appears to be operating as a DC to DC converter, dropping the 144v down to a safe 48v for the motor, as well as providing a host of other features. Even with a switcher dropping the voltage down, there is quite a bit of heat generated in the controller. The Soliton has liquid cooling capability, and [AmpEater] is experimenting with a Koolace PMP-450 system. We’re a bit worried about a PC cooling system standing up to the vibration and abuse a 50” lawn mower can dish out though.
In case you’re wondering, this is not a cheap conversion. The motor retails for over $500 USD, and the Controller for around $2100 USD, and the batteries are around $4500 USD per pack. That’s more than double original price of the Cub Cadet. Understandably, these conversions would be outside the realm of the average homeowner, but they may be worthwhile for a commercial gardener. Even with the recent push toward 4 stroke motors, small engines are still major polluters. We wish we could say an electric mower is quieter than a gas-powered one, however as the video shows, much of the noise lawn mowers create is the blades themselves.