Batteries are heavy eh?
Fuel weight, based on 6.7 lbs per gallon:
747-200B, 361,700 lbs.
DC-10-10, 178,534 lbs.
DC-10-30, 254,700 lbs.
A300B4-200,108,020 lbs.
A300B4-600, 118,390 lbs.
A310-202, 94,800 lbs.
757-200, 78,658 lbs.
767-200, 104,252 lbs.
767-300, 127,300 lbs.
707-320B, 159,898 lbs.
727-200, 70.920 lbs.
737-200, 34,572 lbs.
737-300, 35,912 lbs.
DC-8-55, 156,733 lbs.
DC-8-73, 162,643 lbs.
L-1011-1, 159,560 lbs.
L-1011-200, 178,360 lbs.
L-1011-500, 213,640 lbs.
DC-9-10, 24,273 lbs.
DC-9-50, 28,596 lbs.
DC9-80, 38,725 lbs.
Don’t go getting all practical now, we’re getting our collective crank on about anything that didn’t exist in our heyday.
You have only done half of your homework. See #45 for the other half.
Let’s just say a typical small airliner carries 40,000 pounds of fuel. That’s 18143695 grams. A 18650 Li-Ion cell like those used in the Tesla S weighs 45 grams, to that’s 403,193 cells and a single cell contains 10 watt-hours of energy. So that’s a tad over 4 million watt-hours of energy available for a flight.
A 747 uses about that much energy (90MW for 5 minutes = 4.5MWH) just to get off the ground. But that’s with over 10 times as much fuel weight and an airframe that is 4 times heavier. It is reasonable to expect that a small airliner using modern composite materials and design could be made that would require a small fraction of the 4.5 MWH it takes to lift a 747 off the ground. Let’s say it still takes 1 million watt-hours (which seems quite high) - that leaves 3 MWH of energy for the cruise portion of the flight and landing (where relatively little energy is required).
Li-Ion battery technology improves literally on a daily basis, with an average reduction in weight of 8% per year for the past 5 years for the same energy density. An electric airliner will be feasible once battery technology and airframe design evolve sufficiently. It is a matter of when, not if.