Jill this is really helpful information. I'm thinking of getting a 750W (non-Levo) and the typical battery sizes are 13.5 Ah and 17.5 Ah. I'm at 150 lbs but let's say I'm 160 lbs above for simplicity. The 13.5 Ah x 48V is 648 Wh (right?) that's pretty close to 700 Wh as above, then in theory you can go about 50 miles total before the battery is 100% drained, correct? The other issue is that I'm not sure if 17.5 Ah will fit in my triangle, so 13.5 Ah seems like a better choice if the above numbers are correct.
Not to go off on a tangent but I've read that mid-drives are around 67% more efficient than hub drives. As in 1200 Wh of mid-drive power will go the same distance as 2000 Wh of hub drive, some test on a different site was done between the two a while ago. I currently have a hub drive. Looking back on Strava, a 20-mile, 2350 foot ride will typically drain about 70% of my current 13.5 Ah battery. Adjusting for height down to 2000 feet, let's say that would drain it 65% instead of 70%. Comparing that to your husband's ride above, him getting 50 miles from a mid-drive on a full 100% drained charge to my getting 30 miles on a hub-drive is pretty close to that other test result, a mid-drive is 60% more efficient. No need for 17.5 Ah or 700 Wh with a mid-drive.