Brian Clayton
Well-Known Member
The other day while I was talking to my battery supplier, I asked him about costs for a 30hp or so elec motor, battery pack and controllers, for a UL style plane. They have some experience since they just built a battery pack for the Rutans on a longeze proect. Anyway, the basic idea I gave him was a 30 hp aircooled direct drive motor and batteries to end up with about a 130 pound package all together. I forget the exact weights, but I was trying to figure what a engine and related parts plus a full tank of fuel (5 gal) would weigh. Thats how I settled on 130 pounds. Not well thought out or engineered.....just off the top of my head during a casual conversation. The short version. A 50hp elec motor, derated by rpm limiting HP to about 30 hp @2800 rpm, controller and lithium batteries ending up with a total weight around 130lbs, cost would be about 6500.00 in parts for the electric part. Motor and controller about 1500.00, the rest of the cost is batteries. Depending on load (I guessed 75% of 30hp) you should get 30-45 minutes of flight and takes about 20-30 minutes to recharge. No, I dont remember all the particulars about AH and such. Of course there are many variables here, but I was mostly interested in a basic idea of what it would take to get started without getting into a bunch of engineering. Something to work with, without a bunch of theoreticals. You know, off the shelf stuff. Order it on Monday, be bolting parts on Saturday and fly on Sunday. Just thought it was interesting and I thought I would share. Not very much range, but seems like it would work out for some people.
