needs a B&S v twin.....
If you notice in this Video it must have been made before the FFA made the final Ruling that Battery Weight is Included in the total Empty Weight. Listen at 5:20 where he is talking about it probably coming in at 250 lbs without the batteries!
As Airframe sat, not done yet, he was at 120 lbs, Wings 25 lbs each equals 170 lbs and not done yet. Batteries for 45min of Flight he said was 75 Lbs and you still have Motor & Controller Weight. You still need a Reserve, so more like 35 min, with a 10min Reserve!
The Lazair MTOW 450 lbs with (2) Rotax 185's had an Empty weight: 210 lbs (95 kg). The 185UL 9.4hp each were around 28 lbs x 2 = 56 lbs. 210 lbs - 56 lbs = 154 lbs for Airframe. That left 100 lbs for Batteries, Controller & Motor & Brackets. When the Designer of the Lazair tried to convert it to Electric, 45min was all he could get with (2) 11hp Motors.
Lazair MTOW 450 lbs - 254 lbs = 196 lbs for Pilot & Bags.
A pair of 185UL's gave you 2hrs of Flight with a Reserve on 5 Gallons of Gas.