Lots of questions, allow me to give you lots of answers.....
An electric powered aircraft should not really reduce training times noticeably, you still have to learn to fly! You need to learn all of the navigation rules. air rules etc. but, it should be cheaper in the long run because you are not doing any engine run ups, magneto checks or anything like that. From the moment you start the motor you can simply go 100% power so this should make it cheaper for those learning to fly because they will get the same amount of flight time but with very little ground time.
Every landing is the equivalent of an engine off emergency landing because from mid downwind to touch down the "throttle" is in the off-position and the aircraft is basically a glider for the rest of the circuit. The propeller wind milling during this stage of flight recharges the battery. There is a theoretical recharge amount of 14% in each circuit.
The cost of complete overhaul of the electric motor at 2000 hours is currently €500 in parts +12 hours of labour significantly cheaper than a gasoline equivalent.
The electric motor has three rebuild cycles so it is good up to 6000 hours where the manufacturer declares it should be replaced. The cost of placing the electric motor at 6000 hours with a new motor is €10,000
The batteries can be replaced complete or the cells can be replaced in the battery housings which use a much cheaper option. The cost of a complete replacement battery set is €19,500. The cost of replacing the battery cells only is €12,000. To eliminate the claims of being able to fly for two dollars an hour it is easy to see that the battery replacement cost is $12 per hour. The cost of replacing the motor at TBO is $0.75 per hour. Add maintenance to this every hundred hours which is only lubricating moving parts on the airframe because you don't touch the motor or the electrics until TBO you can see that the true operating cost of this aircraft is below $20-$25 per hour.
The batteries have a display on them showing the temperature of the battery, the state of charge and the health of the battery. New batteries obviously have 100% health but they deteriorate over time. At 1000 recharge cycles the batteries will be showing approximately 75% health. It is completely possible to still fly the aircraft's this configuration but more endurance will obviously be reduced. The manufacturer states that 75% the batteries are at the bottom of the useful life and should be replaced but at 75% you still have a battery system with 30 kW capacity. I am sure there will be a huge market secondhand for depleted aviation battery systems including motor vehicles, homes etc.
The instrumentation on the panel of the aircraft displays the remaining power. We only display it as a percentage of power remaining. We do not display as flight time remaining for obvious legal reasons. If someone looks down and it shows 30 minutes remaining and they increase the throttle 10% then the flight time will be less so we just display the percentage of battery remaining. For a normal flight the useful range of the battery is from 100% (fully charged) down to 20%. We consider 20% to be empty on the batteries. You can still fly the aircraft until the batteries are completely exhausted but you must know that the battery life will be reduced each and every time this is done. The batteries must be managed correctly.
To answer an obvious question, mind you I had to ask this the first time as well. There is no difference in the weight of the aircraft when the batteries are depleted or full (that is measurable)
Everyone must remember that this aircraft has been solely designed for training, the circuit operations only. It has not been sold or marketed as a cross-country aircraft of any description. It has 60 minutes endurance in the circuit area with a mandatory 30 minute reserve.
This aircraft is just the first steppingstone to many big improvements in the future. The next generation of batteries we are currently testing will give more endurance. We have 4 seat electric aircraft already with hydrogen fuel cells that recharge the battery system which can travel more than 1800 km without landing. The beauty of the Pipistrel ALPHA Trainer is that when new battery technology and systems are introduced it is simply a matter of pulling out a 50 kg battery pack and replacing it with new technology.