Conversion project detailed overview

 

Current Powerplant; Rotax 447 

  Max Power: 32kw

  Max Torque: 47nm

  Mass: 40.6kg

  Gasoline and oil pre-mix

  Capacity: 42L (12 gal)

  Mass: 32.6 kg (72lbs)

Aircraft specs:

  Typical flying Mass: 326kg

   L/D Max (with wingtips): 24:1

   Thrust (@L/D Max): 13.5kg

   Kw (@L/D Max): ~7kw  (approximation, there are many factors for this conversion)

Motor specs:

   Twin co-axial

Front Motor:

238100 Brushless and Alibaba Hollow shaft for rear motor pass-through
Max Power:	50kw @ 3600rpm
De-rated Power:	32kw @ 3000rpm
Mass:	7kg
KV (@peak torque):	35
Amps @ peak torque	430A

Rear Motor:

Custom-built axial flux outside stator, inner rotor
Max Power:	35kw @ 3600rpm
De-rated Power:	20kw @ 3000rpm
Mass:	7kg
KV (@peak torque):	35
Amps @ peak torque	430A

BAC 4000

  Input Voltage: 36 - 72 vdc (84 abs max)

  Peak Current: 430 Amps(rms)

  Continues Amps: 430 Amps(rms)

  Price: already own

Mission Profile

Take-Off: 100% power, 2 min

Climb: 66% power, 10 min

Cruise: 32% power (10.6 kw), 90 minutes

Total energy requirement: 19.7 kwh

Battery Pack Details

	Cell Name	molicel p42a 21700
Cell Details	Nominal V	3.6	V
	Current Cap	4.2	Ah
	Capacity	15.12	Wh
	Volume	0.025177666	L
	mass	67.8	g
	cost	$4.75	$
	Max Disch	45	A
	Cont Disch	45	A
Battery Pack	S	20
	P	66
	Unit Count	1320
	Nominal	72.0	V
	Power	20.0	kwh
	mass	89.5	kg
	cost	5,016	$
	Max Disch (theoretic)	2970	Amps
	Cont Disch	2970	Amps
	Specific Energy	223	Wh / Kg

Mass analysis

ICE Mass: 40.6kg

Full-fuel Mass: 32.6kg

Total Legacy Mass: 73.2kg

Electric Motor Mass:7.0kg

Battery Mass: 62.6kg

Total Electric System Mass: 69.6kg
What!? 3.3 kg LIGHTER!

Current Basic Empty Weight: 223kg

Gross Weight: 365kg

Pilot Weight: 

Cost Analysis
Used Rotax 447: $3000

Motors: $3000

Controller: $3000

Batteries: $5,016

Electric system Cost: $11,016   ($8,016 after selling Rotax)

Potential battery layout