#Elaphe ltd aka http://in-wheel.com

boxster1971 I think you are correct! My logic tells me #APTERA is using the 300V motor with 1500 rpm to achieve the more than 100 mph top speed.

Why do I think the Elaphe M700 hub motor and not the S400?

The S400 max revs = 750rpm - The M700 max revs = 1500rpm.

If you measure a wheel rim with a tyre from the centre (at the axle) to the outside circumference of the tyre you get the radius of the wheel. Now do simple calculation the find the circumference of the wheel. Let us say this is 300mm or 0.3 meter - the formula is 2 x phi x radius = 2 x 3.14 x 0.3 = 1.88 meter.

Thus S400 hub rpm x circumference = 750 x 1.88 = 1.414 Km per minute. Thus clock speed as measure inside the vehicle = 1.414 Km x 60 minutes = 84.857 Km/h. For the M700 this would be double @ 1500rpm = 169.714 Km/h (160Km/h = 100mph)

If this is the case then a normal single battery is approx 1.5V - #APTERA will need 200 batteries to do a single layer 300V power supply. To achieve their 1000 mile range #APTERA would need more than one layer. The alternative would be to use a 12V or 24V inverter to convert to 110V / 220V AC and once again via a diode bridge convert the mains voltage back to DC voltage (110VAC x 1.414 = 155VDC or 220VAC x 1.414 = 311VDC)

If each hub motor draws 10A current then 300V x 20A = 6KW. A 100Ah battery would then last approx 5 hours - 5 hours @ 90Km/h (60% of 160Km/h) = approx 450Km. This implies that they would need at least 200Ah battery capacity or maybe even 220Ah battery capacity.

Maybe somebody that knows the true specs could correct my statement here :)

Off-the-shelve components as the battery solution - #APTERA should also look at existing off-the-shelve components for their battery solution like what can be bought here in South Africa: (This 48V 4.8KW unit sells for R 25 995 (@USA $1 = R15 then this would cost $ 1 733)

If 300V is required then you would need at least 6 of these units.

The Sun Pays 4.8 kWh Lithium Ion Battery Pack

Features:

• Price per watt-hour: R 5.42 (@R15 per USA $ = $0.36)

• LCD display

• LiFePO4 cells

• Low environmental impact

• Superior thermal stability

• High peak power rating

• Long cycle life

• Intelligent Battery Management System (BMS)

• BMS communication compatible with Sacolar and Growatt inverters

• RS485 BMS communication

• CAN bus (only available on client request)

• Parallelable up to 15 battery packs to a total of 72kWh

• In order to achieve full capacity, communication between the battery and inverter is required.

Specifications:

Combination method 15S5P

Rated capacityTypical: 105 Ah

Minimum: 100 Ah

Mean operation voltage 48.0-49.5 V

Voltage at end of discharge 47 V

Charging voltage 51.6 V

Internal impedance (measured at AC 1kHz after 50% charge)< 30 m Ohm

Standard continuous charge current 20A - 40A

Maximum continuous charge current 100A (controller by BMS if comm. used)

Maximum continuous discharge current 100A

Operation temperature (at 60±25% R.H)

Charge: 0~45 °C

Discharge: -20~55 °C

Storage temperature (at 60±25% R.H)

less than 12 months: -10~35°C

less than 3 months: -10~45°C

less than 7 days: -20~65°C

Dimensions 442 x 480 x 221.5 mm

Weight 42kg (square cell technology)

Volumetric specific energy 104Wh/L

Gravimetric specific energy 87 Wh/kg

Cycle life:

Battery tested for the following:

Depth of discharge Cycles @ 25°C and 1C (100A)

80% 3500

85% 2500

90% 1250

95% 500

Information copied from this link:

https://shop.thesunpays.co.za/collections/solar-batteries/products/the-sun-pays-4-8-kwh-lithium-ion-battery-pack

The motors are only one part of the solution - to control the beast you also need the instrumentation and controls. Can be found here:

http://in-wheel.com/en/solutions-2/powertrain-electronics/

I think the #APTERA claim of 3.5 seconds is too modest. #Elaphe achieved 3.5 seconds with a standard metal bodied truck they converted into an EV using their own motors and control electronics, #APTERA weight and slim earo-dynamic design should take off like a rocket!

@barry.hendriks Thanks for the advice, I will correct the acceleration. However, I have my doubts, that without further aerodynamic aids, the Aptera will take off ...

And the winner ist ....

@loswa :) No I did not mean lift-off ... It will really push you back into the seat :) I presume with larger diameter tyres - given the max revs as the limiting factor - 19 inch tyres would push the #APTERA past 200 Km/H !!!