Taurus Electro

Taurus Electro G2 is the first and the only electric 2-seat aeroplane in serial production available on the market. It offers complete freedom and independence thanks to the retractable electric engine, double retractable main landing gear, excellent gliding performance, inexpensive maintenance and a well ventilated spacious cockpit.

Pipistrel Taurus price list

Can electric perform better than conventional? Absolutely!

For the first time electric power outperforms its gasoline-powered counterpart – the Taurus. Taurus Electro G2 can use a shorter runway, climbs faster and is performs much better than the gasoline-powered version when it comes to high altitude operations. All this is possible thanks to the specially-developed emission-free Pipistrel’s 40kW electric power-train.

The tailor-developed Lithium-technology batteries come in two configurations, capable of launching the aeroplane to 1200 m (4000 ft) or 2000 m (6500 ft) respectively. They are placed in self-contained boxes, monitored constantly by the super-precise Pipistrel’s own battery management system (BMS), compete with data-logging and battery health forecasting.

The propulsion motor weighs an impressive 11 kg (rather than 16 kg) and generates 10 kW more power, resulting in a total of 40 kW. Due to this 33% increase in power and 40% decrease in weight we developed a whole new propeller, which has proven to be more efficient than the version flying on the Taurus Electro Prototype.

State-of-the-art battery system

Pantera
The state-of-the-art battery system that uses information from the past to see into the future.
The first element of this networked system is the state-of-the-art hybrid battery management system which was developed entirely in house to be able to function with tighter tolerances than commercially available systems, yielding better performance and longer battery life. The Battery Management system monitors the batteries, which were specially developed to be used in the Taurus Electro G2. They represent the absolute pinnacle of today’s battery technology, combining low weight, high power and high energy density to levels that seemed impossible as recently as 2009. The batteries are placed in alluminum boxes with dedicated power and signal connectors. Each battery cell’s performance is monitored, temperature measured and future performance predicted.
The system is able to forecast when a battery cell is mal-performing and signals the need for a premature replacement. All parameters are also logged in the on-board flight data recorder. The four (4) battery boxes are removable and replaceable

Technical data

model TAURUS ELECTRO G2
Motor
High performance synchronus 3-phase electric outrunner with permanent magnets
power
40 kW for takeoff, 30 kW contionus
PROPELLER 2 blade Pipistrel 1650 mm diam special for Taurus Electro G2
PROPORTIONS  
wing span 14.97 m
length 7.27 m
height 1.41 m
wing area 12.33 m2
rudder area 0.9 m2
horizontal tail area 1.36 m2
aspect ratio 18.6
positive flaps 5 deg, 9 deg, 18 deg
negative flaps -5 deg
center of gravity 23% – 41%
WEIGHTS  
empty weight (includes standard battery!)
306 kg
minimum pilot weight 60 kg
maximum total pilots weight 220 kg
max take off weight (MTOW) 450 kg / 472.5 kg / 550 kg
weight of std battery system
42 kg
weight of optional battery system
59 kg
PERFORMANCES  
stall with flaps 63 km/h
stall without flaps 71 km/h
manoeuvring speed 163 km/h
max. speed with flaps extended 130 km/h
max. speed with airbrakes extended 225 km/h (extend at or below 160 km/h)
max. speed with powerplant extended
160 km/h
VNE 225 km/h
min.sink 0.70 m/sec
min.sink speed 94 km/h
max. sink with airbrakes 6.0 m/sec @ 100 km/h
best glide 1: 41
best glide ratio speed 107 km/h
best glide at 150 km/h 1: 33
best glide at 180 km/h 1: 23
max towing speed 150 km/h
45°-45° roll time 3.9 sec
take off run MTOW 160 m
take off over 15 m MTOW 245 m
best climb speed 100 km/h
max climb rate (MTOW) 3.1 m/sec
relative climb (elevation independent!)
1100 m (4000 ft) / 2000 m (6000 ft)
max load factor permitted (x1,8) +5.3g -2.65g
max load factor tested + 7.2g – 7.2g

Frequently Asked Questions

I wish to know more about the batteries used in Taurus Electro G2
Battery type is a special-made LiPoly battery, 10 Ah capacity per cell, 25 C discharge rate. The system includes 4 boxes where the batteries are located, the BMS also. The standard battery configuration is 128 cells, optional are 192 cells. They fit in the same 4 boxes in both cases.

The basic option gives you total capacity of 4.75 kWh, from which it is sensible not to use more than 80% due to battery cell life. Effectively you end up with 3.8 kWh of useful energy. This version fully meets European microlight standards regarding the empty weight! The battery pack weighs 10.5 kg per box, there are 4 boxes, totalling at 42 kg.
The optional pack adds capacity to reach 7.10 kWh total, again by taking 80% »sensible discharge level« you are effectively at 5.7 kWh of useful energy. This battery pack weighs 13.9 kg per box, there are also 4 boxes on board, totalling at 55.6 kg.

What is the endurance of the Taurus Electro G2 in real life?
In terms of endurance the following margins apply for the basic battery pack:
20 kW power output: 11 min 30 sec
30 kW power output: 7 min 40 sec
40 kW power output: 5 min 40 sec (theoretical, expected is 1 min on 40 kW, then reduced power)

The data may change because of ambient temperature. 80% sensible discharge level is taken into account.

In terms of endurance the following margins apply for the optional battery pack:
20 kW power output: 17 min 10 sec
30 kW power output: 11 min 20 sec
40 kW power output: 8 min 35 sec (theoretical, expected is 1 min on 40 kW, then reduce power)

The data may change because of ambient temperature. 80% sensible discharge level is taken into account. Please note that in horizontal flight only 7 kW is needed, so theoretical endurance reaches 1 hour.

What are the variables influencing the top-of-climb capability?
There are a lot of factors for this, from cockpit load, runway condition (how much energy you burn for the taxi&take-off), ambient temperature, thermal properties of different components, controller parameters, etc. Ambient temperature is the most important factor of all.

What maintenance is required for the powertrain?
The maintenance is virtually care-free!
Battery system takes care of itself but needs to be recharged to full charge at least once every 90 days to keep them »healthy«.
Controller maintenance: nothing, just clean the cooling duct.
Motor maintenance: check main bearing for axial free play and tighten main bearing every 10 hours of motor operation.

Is it mandatory to wait a long time until engine is hot before start?
Absolutely not. The colder – the better for the engine. It will not be recommended to apply full power however if the batteries are below 5 deg. Celsius.

How does the Propeller stop and the engine retract? Is it all fully automatic?
Yes. Fully automatic systems include the brake, which is all electric, and positioning via a magnetic 16-bit hall-sonde encoder. When the propeller is correctly positioned, it can retract. The stopping, positioning and retraction of the propeller work flawlessly at the press of a single button.

Is engine and controller cooling adequate even in the summer time Australian conditions?
The cooling is proving to be sufficient. In any case, there is a protection logic built in which will slowly reduce the power on the system if it will be picking up temperature too fast (considers also temperature gradient, not just limit temperatures!)

Is it possible to retract the engine right after stopping it, or is it mandatory to wait while the batteries cool down?
Batteries essentially do not become over 50 deg.C hot. It’s not necessary to cool them down – you can retract immediately at any time, mid-flight or on the ground!

Is it possible to extract and restart the engine mid-flight?
Of course. As with the retraction, it is all automatic.

Is there a recommendation ‘don’t take-off when the remaining power is under a certain percent’ ?
The system will not allow you to do that. If less than 3 minutes of battery endurance is indicated, it will not go to take-off power and it will produce a warning.

How long does it need to charge at 220V?
3.5 hours for the standard battery configuration, 5 hours for the optional configuration. This is when the batteries are completely empty! You can monitor all this via the ESYS-MAN instrument. Charging is also possible form the Pipistrel’s Solar Trailer.

Is charging with 380 is recommended?
No, the charger is a single-phase 220V or 110V.

Is there any built-in safety in case of too high temperature or controller dysfunctions ?
There is a multilayer logic in place. The controller takes care of itself. In case of too high temperature it will first reduce power (up to 5%) and then switch itself off in case of severe over-heating. BUT BEFORE THIS OCCURS THE FOLLOWING WILL HAPPEN:
We have an on-board computer now. It measures not only the temperatures of all components of the system (motor, controller, 4 temperature probes per battery box etc), but also a bunch of other parameters and has the limit temperatures as well as limit temperature gradients programmed inside. For example, if the motor is heating up more than a certain amount of degrees-per-minute, it will reduce power to track the maximum permitted temperature gradient (slope), in order not to reach the limit temperature at all. The same goes for the controller, as well as for the batteries. Manual override is possible, of course. There are warnings which display on the screen, too.

Will parachute remain usable in case of battery overheat / fire ?
Thanks to the super-precise Battery Management System, which was specially developed by Pipistrel just for Taurus Electro G2, battery issues are extremely unlikely. Furthermore, the batteries are placed in self-containted metal boxes in the fuselage. In event of an overheat/fire, the parachute remains fully functional.

How is throttle control executed?
The system uses throttle-by-wire concept. The throttle input is received at the ESYS-MAN, filtered with protection logic and the reference for the RPM is then sent over to the motor controller via CAN bus. It is all very elaborate, not via a simple potentiometer as it is common with other aircraft.