InMotion has fired the next salvo in the Electric Unicycle performance wars. They have announced the V13 Challenger. This could prove to be a very interesting wheel. Here is some of what is known and much of what is not known. We will fill in more data as it becomes available.
FreeMotion will take a look at this new and exciting wheel as presented by InMotion.
The battery pack
InMotion has followed King Song’s lead in making a 126V wheel. They went for more capacity which of course means more weight. Some of the features of the battery are listed below.
• 126V 3024 WH Battery
• BMS volt meter 3% accuracy deviation
• Independent battery logs
• BMS firmware updates
• Redundant protection mechanisms for the battery
• Updated battery pack brackets using a water-resistant sealant
• Heat dissipation improved 10x
• Stainless steel shields to protect batteries
• Numerous temperature sensors
• Packs feature IP67 Waterproofing level
• Fast Charging (2.5 hours) with Smart BMS
The battery system features triple communications pathways allowing redundant control in the case of failure of one of the pathways.
The V13 Challenger, if released with the given specs will have a very powerful motor. The specifications would imply when riding this at 30 mph, the motor would put out a respectable 25 horsepower. (220 lb-ft. x 600 RPM / 5,252).
• 140 kmH/ 87mph no load speed
• Motor is rated at 45k00 W, peak output of 10,000 W
• Motor produces 300 nm/ 220 Ft lbs of torque
• Reinforced rim for rugged riding at higher speeds
• Dual hall sensors for redundancy
• 22″ blades and magnets to keep you rolling
• 8 AWG wiring to handle higher current
The motor of this unicycle, combined with a 22” tire also means the wheel is capable of very fast speeds. These speeds mean that riding at 30 mph would leave a lot of safety margin. The safety margin is the reason to buy a fast EUC. FreeMotion knows that many people want very fast unicycles. We like to discourage riding at very high speeds. Given this, we provide the following information to understand the forces involved in a crash.
Forces in a crash: In order for you to understand these speeds, we have given the speed reached when someone falls from a building. This is assuming 3.05 meters per floor or 10 ft per floor. This will give an idea of what a crash is like at the speed given in the table below.
|Heightto fall from||Speed at Impact (m/s)||Speed at Impact (kph)||Speed at Impact (mph)|
|1st floor roof||7.73||27.8||17.4|
It is clear that InMotion is taking rider and battery safety very seriously. This is a great attitude for makers of EUCs. The V13 Challenger has some innovative safety features, the most important of which are dual Hall Sensors.
Dual Hall effect sensors are built into the wheel which seriously enhances the safety of the wheel. Hall effect sensors, or Hall sensors as they are known, detect both the position and the speed of the motor. This allows the controller to know if and when the motor is moving. It allows a rider to hop onto a EUC while still and yet the controller can control the motor at any speed. However, if the Hall sensor fails, the controller will also fail and the wheel will fall.
Hall Sensors are not needed in an electric scooter most of which use Counter-electromotive force (counter EMF, CEMF, back EMF) to sense motor movement. The disadvantage of this is that the scooter and motor must first be rotating before the controller can get information about the motor’s rotation. There is no Back EMF if the motor is not in motion. This is why many scooters must be pushed before the motor will engage.
By using dual Hall sensors, the controller will continue to function even if one of the sensors goes bad. This gives redundancy to the wheel making it much safer. King Song uses back EMF to serve as a safety redundancy in case the Hall Sensor fails in the S22. This allows for the rider to safely stop the wheel, without a crash, in the event of a Hall sensor failure. However, one would not easily be able to restart the wheel in this case. With Dual Hall sensors, the wheel would remain functional.
InMotion has reinforced the RIM of the wheel allowing for more dramatic off-road riding without facing damage to the wheel. We assume that the V13 will also have an increased load capacity for that reason. Add to this a 22” tire and the V13 should withstand some very heavy potholes or curbs.
Reinforced battery packs on the V13 are used to ensure water intrusion is not allowed. There are stainless steel protectors at the corners of the battery packs. The batteries are sealed allowing for an IP67 rating against water and dust intrusion.
Wire diameter: Larger motors and big batteries mean more current. Already at 126V, this wheel promises some serious electrical current flowing through the wires. For this reason, InMotion will use 8 AWG phase wires to feed electrical power to the motor. Thicker wire means less heat and more safety.
Wheel size: The effect of bumps and road imperfections on a wheel are a function of the ratio of the size of the bump or imperfection to the size of the wheel. The larger the wheel, the more immune it is to bumps and road imperfections. With a 22-inch tire, the V13 challenger should be a very stable performer for both off-road and commuting riders.
FreeMotion understands that the attribute people are most excited about will be the performance. But this wheel promises more than performance. It has a couple of very unique extras.
Fingerprint sensor switch: Most of us do not use the lock that is available in the app that controls the EUC. But the V13 Challenger promises a fingerprint sensor for switching on. This means that no one can start your wheel. It is locked to the user. We want to see the implementation of this but it promises to be very useful.
AutoRetracting pedals: For those who use the wheels to commute, the AutoRetracting pedals promise to be a matter of serious convenience.
Suspension: InMotion has hinted at an electronically controlled suspension system. This could turn out to be very interesting and powerful for a wheel of this speed and power. It could allow for dynamic adjustment of the suspension to compensate for different road services and writing styles.
Fast Charging: At 3 kWh, the V13 Challenger has some serious battery capacity. Without an enhanced charging system, charging this wheel could take forever. InMotion has cited a 2 1/2 hour charging time possible for the wheel. FreeMotion is very excited about the possibilities for this wheel. We do not yet know the weight and some of the other attributes of this unicycle. As we learn more we will keep you informed. But for now, the V13 challenger looks like it’s the next evolution of the electric unicycle.