it has been way to long for me to remember, but there be a few folks on here that have created a custom all electrical tractors. a few run on batteries, and some with a gas/diesel generator on the machine.
the battery version were kinda like them power scooters for elderly and/or those with disabilities. but redid a bit different to a riding lawn mower setup. with a couple basic features.
ya need to be careful with electrical more so electrical motors. a slightest of sparks can send a unit up in flames! this has more to do with grass clippings / dust from mowing, and like. all that dry nice and flammable stuff getting into all the nook and crannies. if using around cutting up trees or firewood, all the dust and like from that also being a source for a possible fire.
batteries can and do explode.
capacitors can hold a charge for a long time, and a short circuit could easily kill ya from the stored up energy. simply disconnecting a battery does not cut it.