We test two main things when reviewing drones – their flying performance, and the camera’s video and stills quality. To test flight, we take the drone out to an approved Flying Field like the one in Richmond Park and check its responsiveness, speed, stabilisation, obstacle avoidance and the accuracy of safety features like return-to-home. We also assess the stability and quality of its video feed from its maximum distance and its battery life claims, based on real world use.

The included 3.7V 650 when fully charged, offers about 9 minutes of flying time, and you only need about an hour to refuel. If you wish to have the drone in action for an extended period, simply purchase additional batteries. With the controller, you have up to 120m of control range, but reduced to just 50m when you activate the FPV mode. Even with this, you can still conveniently take videos at reasonable distances.  
With an altitude hold mode, which keeps the drone at a specified altitude, the Yanni Syma can hover, ascend, and descend at the push of a button, making this one of the easier drones to manipulate in the air once you get the hang of it. At the same time, the Yanni does have similar downsides in terms of charging time, flight distance, and flight time. It takes over two hours to charge, can travel to fifty meters away, and its battery can last for up to ten minutes of flying time. Even with all of these faults in mind, it would be hard to do worse, considering all that you get with it. Best recommended for the more serious beginner interested in FPV drone racing. 
Since repairs are as easy as soldering a couple motors and the flight controller has proven reliable and capable, people have developed a few nice modifications for it. Modifications such as a chassis swap with lighter and more durable materials are fairly easy, even for those without electronics skills, and yield longer flight times as well as further improved handling.
All of these multirotors include the essentials; a battery, charger, remote (more commonly referred to as a transmitter), and of course the quadcopter itself. All of these are controlled using a standard mode 2 style transmitter with the throttle on the left and adjustable trim settings. They all also handle using the same basic control scheme and the same basic auto-leveling flight mode, but much like a car, they all feel distinctly different to control.
The Holy Stone HS100 is another budget-friendly autopilot drone. It has one of the shorter flight times at 15 minutes but is still equipped with headless mode, altitude hold, and one-touch takeoff and landing. This would be a good drone for beginner pilots who are just learning. It has a built-in 1080p, first-person view camera that can capture some great footage. Again, there aren’t as many advanced camera features like the more professional drones have, but the Holy Stone HS100 still makes for a great flight experience.

Please note that if these drones are flown out of range so that the communication with the drone is lost, the drone can be easily lost as well. A common error is to fly the drone to its height limit and lose communication. If there is any wind, the drone may then do what is called a “fly away.” This is a sad thing for an operator because the drone will fly off to who-knows-where and unless you quickly go chase it; it can disappear forever. 
Generally speaking, drones that cost less than $100 bucks aren’t worth your time. They’re flimsy, they lack advanced features, and they’re almost always squirrely as hell in the air. But Tello is different. Despite the fact that it retails for only $99, it boasts a boatload of high-end features and functionality. Under the hood you’ll find a 14-core Intel vision processing chip, flight stabilization tech from DJI, a 5 megapixel camera capable of shooting 720p HD video, and a battery that gets you 13 minutes of flight time.

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