How Beat The High Cost Of Fuel: The ElectraFlyer-C

Scott wrote:
Richard Riley wrote:

On Jun 16, 7:37 pm, Larry Dighera wrote:

How Beat The High Cost Of Fuel

The motor is powered by a 78 pound, custom-built lithium-ion polymer
battery with a power output of "5.6 kilowatt hours"; projected life is
300 to 500 full discharge cycles or more than 1,000 partial cycles.
The battery can be recharged in as little as two hours using a
220-volt charger (or six hours with a 110-volt charger). The cost for
a full recharge is 70 cents with the 110-volt charger. Fishman says
it's feasible to carry a small 110-volt charger as baggage on
cross-country flights.


1 horsepower = .75kw. So 5.6 kilowatt hours is only 7.51 horsepower
hours. Good enough for a short burst to get you to altitude and soar
the thermals, bu you aren't going anywhere cross country.

Compare it to a really inefficient 2 stroke, burning .6 lb/hp-hr.
Your battery is equal to .75 gallons of gas.

Wait a second...5.6 KWH doesn't really tell you how much HP it is, does
it? All it says is that it consumes 5.6KW in an hour. If you only ran
the motor for 5 minutes per hours, the HP would be 12 times that or
approx. 90 HP. Using KW HOURS doesn't tell the whole story. Running a
100W light bulb 10 hours uses 1 KWH and so does running a 500W bulb for
2 hours but the 500W bulb does more work at any instant in time (it's a
lot brighter!). Now, if that motor was rated at 5.6KW, then yes, I'd
agree it is about 7.5 HP.

Scott



The OP stated the motor was 18 H.P. "This year Fishman hopes to fly his
new ElectraFlyer-C (a re-engined Moni motorglider with an 18-horsepower
electric motor)..."