View Single Post
Old 05-24-2013, 01:19 AM   #46 (permalink)
thingstodo
Master EcoModder
 
Join Date: Sep 2010
Location: Saskatoon, canada
Posts: 1,488

Ford Prefect - '18 Ford F150 XLT XTR

Tess - '22 Tesla Y LR
Thanks: 746
Thanked 565 Times in 447 Posts
Update May 18 - second set

Looking up some stuff about Warp 9s:

3500 rpm continuous, 5500 redline. Electric MR2: Warp9 Disaster - overspeed motor

Measured current for a Warp 9, assuming 3500 rpm (rated) at various voltages:
72V, 25 ft-lbs, 196 amps http://www.go-ev.com/PDFs/003_09_02_...preadSheet.pdf
96V, 20 ft-lbs, 155 amps http://www.go-ev.com/PDFs/003_09_02_...preadSheet.pdf

So 48V would involve higher current .. like perhaps 250 or 275 amps, at 3500 rpm, if it can even get there, and perhaps 30 ft-lb of torque.

Plugging 48V, Trojan T105 batteries, 100% DoD, 1000 lbs removed, 500 added, 195/60 R14 tires, 1% incline, no wind, roll resistance of .015 and brake/steer of .003 into EV Calculator EV calculator gives about:
20 mph 48V 70 amps 3600 rpm first gear
25 mph 48V 100 amps 2600 rpm second gear
30 mph 48V 140 amps 2300 rpm third gear
40 mph 48V 175 amps 2100 rpm fourth gear
45 mph 48V 210 amps 1900 rpm fifth gear

Second gear sounds like a winner to me. 25 mph is more than fast enough for a parking lot demonstration. The acceleration should be very good even with lead acid batteries. The used batteries should be able to supply 100 amps for short periods of time. 2600 rpm is fast enough to cool the motor well if we were to make several test runs.
  Reply With Quote