Re: Grid-Battery "Hybrid" Tractors

It isn't my job in life to educate the ignorant. Please go learn some basics.

batteries (Zebra's, sodium/sulfur etc) are excellent :

Energy density ? 150 Wh/kg has been reported. Similar to Li-poly. Even higher for NaS.

Cost ? That's a bit tricky. Currently only one factory in the world produces these batteries.

But I'm looking into this. Remember that this whole large battery business is in it's infancy.

Rob

Requiring 140% of C put back in to get C back out.

Tee-hee, imagine an electric motor coupled directly to the drive wheels of a tractor.

John

The problem is getting enough torque at the low RPMs. It might be possible to design a really large wheel motor with, say, 64 poles, that would run at

112 RPM at 60 Hz, but a really large wheel would still not have enough torque to meet the requirements. Gears or some other speed reduction mechanism are definitely needed for a tractor. Hydraulic motors are a possibility, but they are probably not as efficient as a well made gear train.

Tractor transmissions are already well-defined for an engine with about

1800 to 3600 RPM, so an electric motor would be an easy direct fit.

Paul