Originally Posted by

**Juggernaut**
Ok I’d like to think I have a great understanding of energy consumption. This question may be better suited on an electric car forum, but honestly I’ve never read anything on one that makes me think they know more about batteries than we do, heck we REALLY push our batteries, and have a far better understanding of what is available.

Anyways here is my paradox I just can’t figure out.

The set up:

I am working on converting a small tractor (900 pounds) to electric.

It was powered by an 8 HP Briggs & Stratton

I am repowering it with a 10 HP brushless motor. 10 HP limited by Speed controller.

That’s MAXIMUM 7457 watts.

It will be powered by a dissembled Nissan Leaf battery pack . It will use exactly ¼ of the packs cells (6 cells vs 24) It will have a potential watt hour rating of 2,880 The full leaf pack has a rating of 11.5k/watts

SO 7,457 maximum watt hours from a 2,880 watt hour pack should mean I will only get 0.386 hours of run time. The tractor’s top speed is 4.1 mph matched to the original gas powered top speed via gearing assuming maximum load which is possible.

My range at maximum load SHOULD be 1.58 miles correct?

Ok Here is the paradox. The leaf uses 12,069 watts to maintain 40 mph on level flat ground, and attains a little over 100 miles of range. How can this be? That is more watt hours than it’s battery, it should only have a maximum range of 38 or so miles. It uses 16762 watts to maintain 65 mph. We can assume the slower it goes the less air resistance and the better the range, essentially down to a crawl.

If you reduced the battery capacity down to ¼ as I will did for the tractor it would attain at least a 25 mile range (ignoring weight reduction)

The leaf can drive 25 miles using 12,069 watts to maintain 40mph on a 2880 watt hour pack, yet my tractor will only travel 1.58 miles using 7457 watts on the same pack? How can this be, this just seems straight up paradoxical to me.