Author: Aditya Singh

The Power Distribution Board (PDB) is often overlooked as an outdated component in drone building. While it used to be an essential component, technology has advanced significantly in recent years. Today, PDBs not only distributes power from the battery to the drone’s electronic speed controllers (ESCs), but also to other peripherals such as FPV cameras and transmitters, and even the quadcopter’s flight controller.

Some modern flight controllers have built-in PDBs, but they can be limited by space and may not effectively filter voltage spikes caused by heavy current draws. Despite this, PDBs are still preferred by some builders as they can reduce stress on the flight controller and provide better electrical noise filtering. Additionally, it is often cheaper to replace a single ESC than a 4-in-1 ESC unit.

PDB Sizes & components

Power Distribution Boards (PDBs) come in two standard sizes: 20x20mm and 30.5×30.5mm. The larger 30.5×30.5mm size is more commonly used, as it can handle higher currents and heat generated by larger quadcopters.

High-end PDBs use boards with higher copper content to handle these high currents and heat. A typical PDB includes tabs for soldering the battery and 4 or 6 sets of pads for soldering the Electronic Speed Controllers (ESCs).

The PDB also includes tabs marked as S1, S2, S3, and S4, which indicate the signal tabs for motors 1, 2, 3, and 4 respectively. This is how the Flight Controller communicates with the ESCs and controls the motors. Some PDBs may also include a current sensor and voltage regulators to power the FPV cameras and VTx.

Voltage Regulators

Flight Controllers (FCs) have evolved significantly in recent years, with the integration of voltage regulators being one of the most notable advancements. The inclusion of these voltage regulators allows FCs to provide power to other peripherals and removes the need for additional components.

However, the quality of these voltage regulators on PDBs is often higher than those found on Flight Controllers (FCs). Due to the compact size of modern FCs and the addition of advanced features, manufacturers may cut corners on the quality of the voltage regulators.

The PDBs use switching voltage regulators, which are more efficient and produce less heat compared to the linear voltage regulators found on FCs. This makes PDBs a more reliable and efficient choice for providing power to other peripherals.

Voltage & Current

The size of a PDB (power distribution board) can vary, ranging from smaller 3-inch quads to larger 10-inch X-Class quads. As the size of the quadcopter increases, so do the power requirements. Ultimately, the size of the quadcopter will determine the appropriate type of PDB to use. For smaller quads, a small 20×20 PDB or an integrated PDB with a flight controller will suffice. As the size of the quadcopter increases, a medium-power PDB is necessary for quads between 5 to 7 inches, and anything larger than 7 inches will require an X-class PDB.

Add-on Features

I previously mentioned that PDBs have evolved over the past decade. They are no longer just devices for distributing power but have become multi-functional. Manufacturers recognized the potential of the unused space on PDB boards and, with an eye toward innovation and potential sales, began creating multipurpose PDBs. Matek was the first company to design these types of PDBs.

PDB with VTx

A popular PDB combination is the PDB and VTx combo. Matek was the first company to introduce this concept with the launch of the FCHUB-VTX. This product was a game-changer in the drone community and it continues to be popular today. It eliminates the need for an extra stack in cramped frames and performs the tasks of two separate components. The VTx on the FCHUB-VTX is also noteworthy, as it is one of the highest-performing VTx on the market. It offers 40 channels, a switchable video power supply at 25, 200, and 500mW, and a 184A current sensor. Additionally, when using a Matek F405 FC or similar, the PDB and FC can be connected with a 30-pin ribbon cable, reducing the clutter of cables between the FC and PDB.

Power Distribution Board with FC

The integration of a Flight Controller (FC) with a Power Distribution Board (PDB) is a significant advancement in the drone industry. The compact design of the FC-integrated PDB combo is truly impressive. One of the first companies to introduce this concept was Matek with the F405 CTR.

Despite the combination of two boards into one, the manufacturers did not make any sacrifices in terms of features and performance. The Flight Controller includes all the standard components such as barometers for measuring atmospheric pressure and flash storage for flight data. Additionally, the PDB also maintains a high level of performance, with a current carrying capacity of over 30A.

Current Sensors

Current sensors are an essential feature in today’s drone building. They measure the amount of current that the quadcopter draws, which is crucial for ensuring the proper functioning of the PDB and the batteries. This is particularly important for 22xx motors, which can draw more than 30A per motor. Many manufacturers don’t provide accurate measurements of current draws, so current sensing is necessary to monitor the motors and prevent overloading the PDB or stressing the batteries.

4 in-1 ESC

A 4-in-1 ESC, as the name suggests, is a single board that includes four ESCs (Electronic Speed Controllers). They are highly compact, lightweight, and greatly reduce the complexity of wiring. Due to the integration of multiple ESCs on a single board, the need for using a separate PDB is eliminated.

4-in-1 ESCs tend to be more cost-effective compared to using individual ESCs. For example, the HolyBro Tekko 65A metal 4-in-1 ESC costs $90, while four individual HolyBro Tekko 65A metal ESCs would cost $124. Both options have similar specifications in terms of voltage and current support, but the 4-in-1 ESC offers a 25% cost savings.

In addition to cost-effectiveness, 4-in-1 ESCs are also becoming more reliable. However, one downside to using a 4-in-1 ESC is that if one of the ESCs fails, the entire board becomes useless, even if the other three ESCs are still working properly.

For further reading about ESC, read our post on how to choose ESC for your quadcopter

Conclusion

The necessity of a Power Distribution Board (PDB) for quadcopters is a topic of debate. Some argue that advancements in the drone industry have made PDBs obsolete. However, I believe that PDBs are a classic and fundamental component of building a quadcopter. They play a crucial role in distributing power evenly throughout the circuit, which is an important task that cannot be replaced.

I also believe that using a standalone PDB with an integrated VTx (Video Transmitter) is a better option than using separate PDB and VTx components. The high quality and efficient voltage regulators of a standalone PDB justify the cost.

Brushless Motor Kv, which stands for “Rotor Velocity Constant”, is a crucial factor in determining a motor’s efficiency, agility, thrust, flight time, and other characteristics. It is defined as the increase in rotor rotations per minute (RPM) when voltage is increased by 1V when the motor is running without any load.

If you are looking for a complete guide on choosing motors for your build, take a look at our post here.

Size Matters

In the RC (radio control) world, brushless DC motors are typically marked with a 4-digit number: XXYY, where “XX” represents the stator width and “YY” represents the stator height. The torque of a brushless motor is directly related to the stator width and height, with wider and taller stators capable of producing higher torque.

5-inch quadcopters commonly use motors that are marked with numbers such as 2205, 2206, etc. These markings only refer to the stator and do not include the rotor, as seen in the image above.

The dimensions and Kv rating of the motor are typically marked together. A typical motor mark would look like “2206/2300”, where the second number refers to the Kv rating of the motor.

The operation of both brushed and brushless motors in drones is based on the principle of electromagnetism. An electromagnet in a drone motor is composed of a metal core with copper windings that can be magnetized or demagnetized by applying an electric current.

The Kv Rating

Kv or the “Velocity Constant” represents the speed at which the motor rotates per volt applied to the motor. For example, if a 3500Kv motor is powered by a 4s (14.8V) battery, the maximum rotation speed of the motor would be approximately 3500×14.8=51800RPM. It’s important to note that this is calculated under ideal conditions and theoretical assumptions (without any load) and in reality, there will always be some load such as props, and due to air resistance, the motor won’t be able to reach that RPM, it will always be a little lower.

Motors with a higher Kv rating will rotate the propellers faster, however, they will have less torque compared to lower Kv motors. That’s why it’s suggested to use larger props with lower Kv motors, as they will provide more torque. On the other hand, higher Kv motors are more efficient with higher RPM, but at the cost of torque.

It’s important to note that when moving away from ideal conditions and theoretical assumptions, the situation can become more complex. Kv is not an indicator of a motor’s power, its ability to handle high current, or its efficiency. Instead, it’s recommended to rely on thrust tests for these calculations.

To understand it more in-depth, when a magnet is moved near a copper wire, electricity is produced in the form of voltage. Similarly, when a motor rotates, it creates a back electromotive force (EMF) that can be measured in volts. It’s best to think of Kv as a motor constant, where the motor generates 1V of back EMF per a certain number of rotations. For example, if a motor generates 1V of back EMF per 2500RPM, it’s a 2500Kv motor. If a motor generates 1V per 1650RPM, its Kv rating is 1650Kv. Therefore, measuring the correct RPM and voltage is the simplest way to calculate the Kv rating of any brushless motor in the RC world.

Overloading the motor is a common cause of stator burnout. When a drone is loaded more than what the props can lift, the motor will heat up, causing the internal isolation to melt. In this tutorial, we will explain how to rewire a brushless motor that has been damaged due to burnout of windings, thus saving you the cost of purchasing a new one.

Let’s talk about Torque

The relationship between Kv and the torque of a motor is important to consider. Kv is used to calculate the current required to achieve a certain torque level. The torque constant (Kt) is inversely related to Kv, meaning that as Kv increases, Kt decreases.

The relationship between current, torque, and Kv are closely related. Motors with lower Kv require less current to rotate larger propellers and therefore have a higher torque (Kt), but are less efficient with increasing RPM. Conversely, motors with higher Kv require more current to rotate larger propellers but are more efficient with increasing RPM.

In summary, motors with higher Kv require more current to achieve the same torque as motors with lower Kv.

Is higher always better?

As previously discussed, the Kv rating of a brushless motor indicates the RPM of the motor per 1V of the voltage applied. However, it is important to note that a higher Kv rating does not always mean that the motor is better. The relationship between Kv and torque, as well as the size of the propeller, should also be taken into consideration when choosing a motor.

Summary

• When the voltage is increased, it results in higher RPM but also a higher current. A current that is too high can damage the motor.
• The torque is directly proportional to the current.
• The current drain is highest at lower RPMs (at full throttle) and decreases as RPMs increase. To achieve maximum RPM, multiply the Kv by the battery voltage. However, it’s important to note that rotating the motor too slowly can also damage it.
• A larger prop diameter or pitch results in a heavier load which slows down the motor. The goal is to use a prop that accelerates the motor enough to have a current that is low enough to not damage the motor. This is the formula for maximum power.
• The C-rating of the battery must be high enough to deliver the necessary current to the motor. The result of C * mAh * 0.5 should be greater than the current the motor is drawing.
• The ESC must be able to handle more current in Amps than the motor is drawing. It’s ideal to use a 0.75 factor in the calculation, meaning that a 40A ESC would be sufficient for a 30A motor.

When choosing a frame for your drone, it’s important to consider the material it’s made of, as it can greatly affect the performance and capabilities of your drone. Carbon fiber, wood, metal, plastic, and fiberglass are all common materials used in drone frames. The frame acts as the foundation that holds your drone together and enables it to fly. However, it’s important to note that there isn’t one perfect frame for all drone needs, as different frames are better suited for different purposes. In this guide, we’ll go through the factors to consider when selecting the best frame for your quadcopter drone.

A drone frame?

When building a drone, the frame is one of the most important decisions to make as it plays a crucial role in determining the size, materials, thickness, space, style, and even the geometry of your build. Whether you’re building a lightweight high-speed racer or a durable bando slayer, the frame is the foundation that holds all the other components in place. It also protects the FPV cameras, flight controllers, video transmitters, and other electronic components from damage. It’s crucial to choose a frame that meets your flying needs.

The main purpose of a frame is to protect the components inside and hold everything together. However, in racing frames, the focus is on reducing drag and limiting the effect the arms have on the thrust from the prop, which may lead to some compromise on the protection of the components. The aerodynamics of the frame do not provide lift or control surfaces like in a conventional aircraft. It’s important to remember that without motors, a drone will fall out of the sky.

Personally, I prefer a strong freestyle-focused frame that can withstand crashes without total damage. This means my quads are heavier than most race frames, but I don’t need the all-out speed. I also have a few racing frames, but my favorites are my 5-inch freestyle frames. When choosing a frame, the main factors I look for are strength, space, and a mount for an HD camera (for filming my flights). Strength is important because you will crash, and a strong frame will protect the electronics and allow for multiple crashes. Space is important because it allows for easy installation of parts and maintenance. An HD camera mount is not essential for everyone, but it’s something I value for filming my flights and capturing great footage.

Different parts of a drone frame

Drones have 3 main components: a top plate, a bottom plate, and arms. The top plate, which is typically thinner, often has holes for cable ties and battery straps and may also have a mount for a GoPro camera. The bottom plate, the thickest part of the frame, is designed to absorb crash impact and has holes to accommodate the standoffs for electronics. The arms, which may be part of the bottom plate or removable, hold the motors and sometimes the ESCs.

The size of the frame, measured as the distance between two motor mounting holes along the diagonal, determines the size of the propellers and motors that can be used and is categorized based on propeller size. The most popular frame sizes are 5-6 inches for their agility and durability, with 3-4 inches gaining popularity for their nimble handling. If flying indoors is the primary goal, it is recommended to keep the frame size under 100mm.

Types of Material

Carbon Fiber

Carbon fiber is a popular material for drone frames because of its lightweight, strength, and rigidity. However, it is not the cheapest option, can be difficult to work with, and conducts electricity, requiring additional insulation for wires. Additionally, carbon fiber can interfere with radio frequencies, requiring careful placement of antennas.

Thermoplastics

Other materials used for drone frames include plastic, such as HDPE (High-density Polyethylene), which is designed to withstand significant impacts without breaking. However, the disadvantage of plastic frames is the added weight and limited options for fitting components. The choice of hardware, such as standoffs, bolts, and screws, should also be considered. Steel and titanium are common options, with steel being less expensive but softer, while titanium is more expensive but harder and may cause issues with corrosion when mixed with other metals. Some frames also incorporate aluminum or titanium parts, which offer a high level of strength but come at a higher cost and added weight.

Different frame sizes

The size of a drone frame is typically determined by the diagonal distance between the motors, which dictates the size of propellers that can be used. The measurement for frames is in millimeters, while propellers are measured in inches. Despite this discrepancy, it is common to refer to drones by their propeller size, such as 5 inches or 6 inches.

Size range that is generally true (but not always):

Frame Size	Prop Size	Use	Example
280mm+	7 inch	Long Range	Mode 2 Shredder 7″
250mm	6 Inch	Long Range / Freestyle / Racing	Halo Archon
210mm	5 inch	Freestyle / Racing	Impulse RC Reverb
180mm	4 inch	Freestyle / Racing	Armattan Gecko
150mm	3 inch	Freestyle / Racing	SlightClub Phuket 3″
112mm	2 inch	Freestyle / Racing	Emax Baby Hawk R
100mm-	Whoops*	Indoor / Limited outdoor	Tiny Whoop

The most commonly used frame size in both freestyle and racing is the 210mm (or 5-inch) frame. This is because it provides a good balance between power, weight, and responsiveness. It allows for the use of 5-inch props, which offer high power and efficiency while keeping the weight of the frame low and the center of the props close to the middle. This improves the moment of inertia and allows for more force to be applied closer to the center of mass of the quad. The freestyle scene is mostly dominated by this frame size, with a few exceptions for those who use 6-inch frames.

As the frame size increases, wind resistance becomes a bigger factor to consider. 150mm (3 inch) frames are fast but can be easily blown around and have short flight times due to the need to carry smaller batteries. 4-inch frames are not as popular because they do not offer the same speed as 3-inch frames and the control is not as good as 5-inch frames.

As for 6 and 7-inch frames, they tend to face more air resistance but have bigger props that provide more power. They are often used for long-range flights and prioritize efficiency over raw power. It is important to note that while a 210mm frame can take a 5-inch prop, the clearance between the frame and the props can be very small, so it is important to check these clearances before each flight.

Shapes and Layout

The design of a quadcopter frame is determined by the arrangement of its arms. The most common layout is the 4-arm setup, which includes several variations such as H-frame, True X-frame, Hybrid X-frame, Stretched X-frame, and Square frame.

The H-frame features arms extending directly from the body, resulting in a bulkier design with limited motor placement options. The True X-frame has an equal distance between all motors, providing balanced performance. The Hybrid X-frame combines the best features of the H and X-frames, resulting in a longer body and optimal arm placement. The Stretched X-frame moves the front and rear propellers farther apart to improve high-speed handling but requires more tuning. The Square frame is an enclosed X-frame, offering increased strength but at the cost of added weight and drag.

Unibody design

A unibody frame is a design where all the arms are integrated into the bottom or top plate, as opposed to separate arms. This can come in the form of a single piece or as pair, such as having both front arms as one piece.

Why does this matter?

A unibody frame is said to be stiffer and stronger because it has fewer joints and potential weak points. However, if an arm is damaged, the entire plate may need to be replaced, which can be costly. On the other hand, separate arms can be easily replaced if damaged. This is a common practice in racing frames that prioritize low weight and are willing to replace broken arms. Some designs have clever mountings and screws to mitigate the potential issues with more joints. Ultimately, the choice between a unibody and separate arm design is a matter of personal preference.

Thickness

The strength of carbon fiber is influenced by various factors such as quality, layering, flexibility, and thickness. While it is not always the case that thicker carbon is stronger, it is important to use thicker carbon in areas of the frame that are most at risk of damage. However, thicker carbon also increases the weight of the frame. The bottom plate is often a crucial component as it withstands most impacts and holds the frame together. If using separate arms, one can opt for lightweight arms that are easily replaceable or heavier arms that can withstand more damage. As a general guideline, using 4mm carbon for the main components like the bottom plate and arms can provide good rigidity and strength. For the top plate, 3mm or 2mm is sufficient as they are usually easier to replace.

Racing Vs Freestyle

There is no definitive distinction between freestyle and racing frames as some people use freestyle frames for racing and vice versa. In general, freestyle frames are designed to be stronger and have more space for camera mounts, while racing frames prioritize weight reduction. Some pilots use both types of frames, with a dedicated race frame for speed and response, and a freestyle frame for flow and maneuverability. For beginners, it may be beneficial to start with a freestyle frame as they are typically easier to repair and can withstand more crashes.

Battery Location

The placement of the battery can greatly affect the handling of a drone, as it is a significant portion of the craft’s weight. The goal is to position it as close to the center of gravity as possible. The two common options are to mount it on top or underneath the frame. Freestyle frames often have a top-mount battery that is inline with the frame, offering protection during crashes but not optimal for performance. Racing frames typically use a bottom-mount battery, which improves cornering but increases the risk of damage in crash landings. Additionally, some frames incorporate a mid-mount battery that evenly distributes weight across the frame but requires a specific frame design to prevent interference with the propellers.

Other Considerations

The placement and angle of the FPV camera is crucial for a good line of sight, as it is what you use to navigate your drone. It is common for some propellers to be in view, especially on stretched X-frames, but the camera should not obstruct most of your view. A range of angles is also important for optimal performance, as the camera angle can greatly affect your flying experience. If the angle is too low, you may end up looking at the ground more often than where you are going, and if it’s too high, you may go too fast everywhere. If you’re just starting out, a tilt angle of 25 to 30 degrees is a good starting point. Some pilots use 60 degree tilt angles, but it is not recommended for beginners. Camera protection is a matter of personal preference, as some pilots prefer to hang their camera out the front with no protection for the best view and extreme angles, while others prefer to keep it slightly more protected inside the frame, which may limit the angles but decrease the likelihood of camera damage in a crash.

When selecting a frame for your drone, it’s important to take into account the size of your camera. There are three main sizes of the camera to consider:

• Standard size: 28mm wide, often referred to as Hs1177 size cameras
• Mini size: 21.8mm wide, but often come with brackets that allow them to fit into standard mounts
• Micro size: 19mm wide, Some come with upsizing mounts but most don’t

Make sure that your chosen frame can accommodate your camera to ensure proper fit and function.

HD Camera Option

Most freestyle drone frames come equipped with a built-in mount for attaching a GoPro or other high-definition camera, allowing for the recording of high-resolution footage. Some frames also have space for a 3D-printed mount. While there are also mounts specifically designed for racing frames, they are not always the main focus.

Personally, I prefer to use 3D-printed mounts as they allow me to secure my GoPro as close to the frame as possible to prevent the loss of both the camera and the footage.

Another important aspect to consider is protection for the motors. Damaging motors can be a major inconvenience and often means the end of a flying session. To protect the motors, many frames have the ends of the frame arms extending past the bottom of the motor. This way, the frame takes the impact instead of the motor. Some people also use 3D-printed bumpers for added protection, but this can add weight to the drone.

Spare Parts

Having a reliable source for spare parts is crucial for maintaining your drone’s airworthiness. Having multiple arms on hand, for example, can mean the difference between a frustrating crash ending your flying day and being able to quickly replace a damaged arm and continue flying. However, if your frame has a unique design and is hard to find replacement parts for, it can lead to extended downtime.

For those with a unibody design, the cost of purchasing a spare bottom plate might not be worth it, therefore, it is best to be prepared for possible downtime in this case. Other parts such as stand-offs are usually readily available and often come included in the original packaging.

Warranty, etc.

Warranty coverage is a major factor for me when choosing a drone frame. Some manufacturers offer limited or unlimited warranties on their products, with specific terms and conditions outlined on their websites. This means that if you crash and damage a component like a bottom plate or arm, you can claim it under warranty and receive a replacement at no additional cost, with the exception of shipping fees. This greatly reduces the risk for me, as I know that I have the option to receive a replacement part without incurring additional costs. I have used this on multiple occasions and it has saved me money in the long run. In my opinion, Armattan offers one of the best warranties in the market. As long as you follow the rules, they will ensure that you can keep flying. Additionally, having a spare arm on hand means you can quickly replace a damaged one without having to wait for the replacement to arrive.

Did you know that the size, pitch, design, and weight of a quadcopter prop can greatly affect the way your aircraft flies? These props can be described by their power, grip, efficiency, speed, maneuverability, and durability. In this article, we will discuss how to distinguish between different types of props and how to choose the one that best suits your needs.

Understanding the numbers

When looking at quadcopter props, you may notice that they have a series of numbers associated with them. While different companies may use different naming conventions, these numbers can provide useful information about the prop’s characteristics. Let’s discuss how to interpret these numbers.

Manufacturers use 2 types of formats:

L x P x B or LLPP x B

L- length, P – pitch, B – number of blades

We will use HQthe V1s series as an example. One popular model that I use is the HQ 5 x 4.5.x3 v1s. Here we see 3 numbers. The first 5 indicates the size of the prop, in this case, 5, which means 5”. The second number 4.5 refers to the pitch of the prop. And the last number 3 refers to the number of blades on the prop. V1s is the props designation or model. 

Characteristics

Propeller Size

Props range from Tiny Whoop class 31mm variety, o 6”+ long-range size, to even bigger for commercial or Prosumer applications like DJI Inspire or Phantom.

Prop Pitch

The prop’s pitch can be thought of as using a paddle in a canoe. Pushing straight back with the paddle parallel to the water will provide the maximum force, but each push will be slower. Pushing at a high angle allows you to move faster through the water, but with less force. Similarly, a prop with a high pitch will provide less thrust but will spin faster, while a prop with a lower pitch will provide more thrust but will spin slower.

A lower pitch will always move faster but push you ahead with less thrust.

A higher pitch will mean more thrust per revolution, for greater speed but less fine control.

A prop with a higher pitch will provide more thrust and also spin faster, but it will also have a higher amp draw which will demand more power from the battery. This can be beneficial in some situations, such as when you need more speed or lift, but it can also put more stress on the battery and drain it more quickly. It’s important to consider the balance between the increased thrust and the added power demands when choosing a prop with a high pitch.

Number of blades

The number of blades on a prop can affect both flight performance and efficiency. Fewer blades will generally result in more speed and less amp draw, making the flight more efficient. However, fewer blades also mean less control in the air. More blades can provide more control, but at the cost of lower efficiency and lower speed. It’s important to consider how many blades you want on your prop, depending on the flight characteristics you desire.

A common compromise when choosing a prop is to use a 3-blade prop for most 3-7 inch quadcopters, as it provides a balance of speed and control. For high-speed builds, 2-blade props are often used to maximize speed and efficiency. For indoor crafts where control is prioritized over speed, 4-blade props are often used. It is important to consider the specific needs of your build and the type of flying you will be doing when choosing the number of blades for your prop.

Material

Props today are most commonly made of polycarbonate. Different combinations of materials, colors, and ingredients can affect the stiffness of the prop. A more rigid prop can allow for very fast speeds, but it can also be more prone to breaking on impact. A more flexible prop can be more durable, but it may not perform as well at high speeds. It’s important to consider the intended use of the aircraft and the type of flying when choosing a prop, as it will affect the trade-offs between speed and durability.

Motor and propeller pairing

When choosing a prop, it’s important to match it with the appropriate motor. A smaller motor like 2205 will not be able to efficiently push a high-pitch prop like an HQ 5×4.8 v1s and will drain the battery quickly. It would be better suited for a lower-pitch prop like a 5×4.3 v1s.

A larger and heavier motor like 2207, can handle a larger prop and provide maximum straight-line performance, but it will also demand more power from the battery. It’s important to keep in mind that as you increase the size of the prop, you will also increase the power demands on the battery and the motor.

When testing a new prop, it’s important to land and checks the motor temperatures, as well as monitor the voltage readout on the On Screen Display to avoid over-discharging the battery.

Installing Propellers

Installing props on your quadcopter requires a tool to tighten or loosen the propellers. An 8mm wrench or socket wrench will work, but it’s recommended to use a dedicated prop tool such as the Piroflip branded one.

Pro Tip: A pro tip is to keep multiple prop tools with you. It’s easy to misplace or forget a tool, so having a backup can ensure that you can change a prop even if you’ve misplaced one. For smaller T prop sizes, you will want a 1.5mm hex driver. This will make sure that the props stay tight and secure during flight, and can be easily removed and replaced when needed. It’s important to have the right tools on hand to ensure you can make repairs or adjustments as needed while out flying.

Propeller Direction

There are two propeller direction options: traditional and reverse. In the traditional beta flight setup, all propellers turn inwards. In the reverse setup, the propellers turn outwards. Both options should feel the same in the air, but the reverse setup can help to push the quadcopter away from objects, while the traditional setup will pull it in.

However, the downside to the reverse setup is that it can throw debris such as cut grass, dirt, or grime into the center stack of the quadcopter when landing. It’s essential to consider the environment in which you’ll be flying and choose the propeller direction that best suits your needs.

When installing propellers, it’s important to be aware of the direction they’re facing. In traditional mounting, the blade should point down on the left side when viewed straight on and be mounted on the top left. If the blade points down on the right side, it should be mounted on the top right.

The rear propellers are installed in the same way, across the diagonal. This is one method to remember the orientation of the propellers, but you may find other methods that work better for you. It’s important to keep in mind that the traditional mounting may be preferable if you fly near a lot of trees as it can reduce the chance of debris being thrown into the center stack of the quadcopter when landing.

Size Recommendations

Indoors

Quadcopter propellers, also known as props, play a crucial role in determining how your aircraft flies. The size, pitch, design, and weight of the props can greatly impact the power, grip, efficiency, speed, maneuverability, and durability of your aircraft.

When choosing props, consider the number of blades, the material they are made of, and how they match up with your motor. When installing props, make sure to have the right tools and pay attention to the direction of the props. Also, it’s important to keep in mind that the propeller’s size also varies, 31mm or 40mm are the whoop class sizes and are typically safe to fly indoors. Always test new props and keep an eye on your battery to avoid over-discharge.

Small Playground

When it comes to quadcopter props, I personally prefer the 2.5” size. This size is perfect for a 4S setup with a target weight of 80-100 grams dry weight as it provides enough speed for a fun flight, yet the craft remains relatively light. This size is ideal for flying in an empty playground.

Another great option is the whoop class due to its 25-35 gram weight and the added protection of ducted guards, which can prevent damage in case of impact. My top choice in this category is the Gemfan 2.5” 2540 Flash series prop. Many pilots also prefer the attractive design of the HQ prop.

Large playground

Or small field, parking lot – 3” – There are 2 main types of 3” props, the traditional size prop nut where the Gemfan 3052 Flash prop is king. Or the T-style Mounting prop, where the HQ 3” T-style prop is an excellent choice.

Gemfan recently released a Wind dancer version that comes with a set of adapters that allow you to run both regular-size props or T-style mounting props to accommodate a wide range of motors.

Racing

For racing, the 5” prop is the standard. You can play with the pitch and pairing of your motor to find the right mix for you.

Freestyle

Like racing the 5” is the standard, but often different pitches can be popular for additional response preferred over top-end speed.

Long Range

When it comes to 6″ and 7″ props, these sizes will require more power, but experienced long-range pilots have discovered that by pairing them with a large battery and the appropriate mid-KV motor, they can achieve extended flight times. Popular choices among 6″ props include the HQ 6×4 and Dal 6×4, with the latter being known for its smooth flight but less durable than 5″ options. When it comes to 7″ props, the HQ 7×3.5 is a good option for high throttle ranges, but for overall versatility, the Dal 7x.56 is considered to be the best. One important thing to keep in mind when going for 7″ or larger props is to look for ones with thicker blades, as suggested by the long-range community.

Wings

For wings, while many do run Quadcopter props, APC makes a range of purpose-built props specifically for wings. These involve a lot of variation based on your needs, size of wing, weight, specs, and purpose. So before you dive in, consult your local Wing Commander for more advice.

When should you change the props?

When a crash occurs and a prop becomes bent, it’s common to bend it back into place and continue flying. Some prop models may return to their original shape and remain undamaged, while others may retain a crease. Any damage such as creases, cuts, nicks, or missing chunks will negatively affect flight performance. The latest Beta Flight software with dynamic filters can help mitigate some of these issues, but it’s important to be aware that these scenarios may put additional stress on your electronics. If you are running low on props, it’s possible to continue flying, but it’s crucial to always check motor temperatures when landing to ensure that any damaged props are not causing overheating.

It is important to avoid risking damage to expensive motors or electronic speed controllers by replacing inexpensive props when they are damaged. As a general rule, if you have any doubts about a prop’s condition, it is best to replace it. Keep in mind that newer props typically provide better, smoother, and faster flight performance. When learning to fly, it is important to avoid developing muscle memory with faulty props, so it is best to replace them as needed. If you are doing light freestyle, a set of props may last a long time, but if you are racing, it may be necessary to change props multiple times in a single day to ensure maximum performance. When pushing your quadcopter to its limits with a hard throttle, it is especially important to be mindful of damaged props as they may put your electronics at risk.

It’s important to always keep a good supply of props on hand. Running out of props can quickly ground your flights. To avoid this, it’s a good idea to stock up on your favorite props, especially when they are on sale. By taking advantage of bulk discounts and seasonal sales, you can get the most bang for your buck. Consider purchasing 20-40 sets at a time to keep a large stock.

Conclusion

As an FPV pilot, it’s important to have a variety of props on hand. While it’s a good idea to have a favorite set and stock up on them, it’s also important to try new options in order to find the best balance of control, speed, durability, and cost. Finding the perfect prop that lets you fly to your full potential is a constant journey. To get the best value, I take advantage of bulk pricing discounts and order 20-40 sets at a time, keeping a large stock. This allows me to combine bulk discounts with seasonal sales and stock up at the lowest price possible.

Drones, specifically quadcopters are complex machines in which many parts work together to achieve the same objective which is to fly. So in this post, we will take a look at various drone components or parts that we will need to build one ourselves.

The first step to building a quadcopter is to understand the components that it uses to fly.

A quadcopter consists of the following essential parts:

• Frame
• Motors
• ESC (electronic speed controller)
• Propeller
• Battery
• Flight Controller
• RC Receiver

To get a good view, you’ll need the following components as well:

• A Camera (preferably HD)
• Video Transmitter / VTX
• 5.8 GHz antenna

There are other non-essential but useful hardware for example buzzers, LEDs, HD Camera, GPS, etc.

But before getting into the drone parts, you should always fix the weight or size of the drone that you intend to build. This will help you in deciding everything after that.

Frame

The frame of a quadcopter serves as the main structure or skeleton on which all other components are mounted. When deciding on the purpose of your craft, such as aerial photography, racing, or micro freestyle, it’s important to choose a size that best suits your needs. The size of the frame will determine the size of the props, which in turn affects the size of the motors and the current rating of the ESCs.

A helpful tip for builders is to ensure that the frame’s mounting pattern for the flight controller and motors match your chosen components. Full-featured flight controllers typically have a 30.5 x 30.5mm mounting pattern, while motors for 5” props often have a 19 x 12mm mounting pattern.

First-time builders should consider a well-documented frame that is easy to work with and offers great access to the components. The Diatone 2018 GT M200 is a great example of such a frame. It is both sturdy and spacious, though it may limit the choice of parts. Additionally, this frame offers great protection to the components, which is important as crashes will happen.

Tutorial: How to choose drone frames?

Motors

The motors are the primary source of power consumption on your quadcopter, making it essential to select an efficient combination of propellers and motors. Motor speed is typically measured in kV, with lower kV motors producing more torque and higher kV motors spinning faster. However, this is without the propeller attached.

There are several factors that contribute to motor performance, with the current draw being one of the most important. Be sure to check the specifications of your motors for their maximum amp draw, and ensure that your ESCs are capable of handling this amperage.

A useful tip for builders is to keep in mind that the brushless motors commonly used in mini quads have three wires. The direction of rotation can be set with the software as well.

Note: When installing the motor, be sure to use screws that are the appropriate length to avoid contact with the stator windings. This type of contact can lead to a short circuit and damage the motor. Additionally, make sure any grub screws are securely in place and tightened.

Tutorial: How to choose drone motors?

PDB

A Power Distribution Board (PDB) is a device that distributes power from the battery to various components in the system. The PDB usually connects to the battery through a lead, such as an XT60 connector. However, recent advancements in technology have led to the development of All-In-One (AIO) components that can perform the same function as a PDB. These components, such as Flight Controllers (FC) and Electronic Speed Controllers (ESC), have a wide input voltage range and can output a stable voltage to power other components, such as an FPV camera. Builders tip: Before installing a PDB, consider if it is actually necessary for your build, as many components are now able to distribute power on their own.

Note: AIO is a common term used for components that can fulfill more than 1 function, ie. an AIO FPV camera will be a camera and VTX (video transmitter) integrated into one unit.

Flight Controller

The Flight Controller (FC) is the primary control unit of a quadcopter. It contains sensors that allow it to understand the craft’s movement and, based on the data provided by these sensors, the FC uses algorithms to calculate the required speed of each motor for the craft to respond to the pilot’s input from the Radio Transmitter (TX). Most of the wiring in a quadcopter is connected to the FC. It must be connected to the Receiver (RX) to receive the pilot’s commands, and the signal and ground wires of each Electronic Speed Controller (ESC) must be connected to the FC for the motor commands to be executed. With the introduction of BetaFlight OSD (On-Screen Display), even the video feed from the FPV camera goes through the FC to the Video Transmitter (VTX).

Builders tip: Keep in mind that more functions often mean more wires. For beginners, an “all-in-one” FC might sound appealing, but the wiring can become complex and tightly spaced, making it difficult to solder. Before starting to trim wires, test fit your components to your frame, and remember to measure twice, and cut once!

Note: Some All-In-One FCs integrate various components such as receivers and VTX and even ESCs. This integration is controversial in some circles.

Tutorial: How to choose a flight controller?

RX (Radio Receiver)

Transmitters (TX) and receivers (RX) are not interchangeable and must be matched in order to work together. For example, a FrSky Taranis transmitter cannot be used with a FlySky receiver. Currently, the most common protocols used are PPM or digital Serial, which only require one signal wire for all channels, as well as power (3.3v or 5v) and GND. The signal wire is connected to one of the UART terminals on the Flight Controller (FC). Some FCs have integrated receivers, but it is important to ensure that the protocol used is compatible.

Builders tip: Make note of which UART the RX is connected to, in order to easily configure the FC to communicate with the RX in BetaFlight Configurator.

Note: Spektrum-based receivers usually require 3.3v, while FrSky and FlySky RX require 5v. Never supply 5v to an RX that only requires 3.3v, as it can damage the receiver.

Electronic Speed Controller (ESC)

An Electronic Speed Controller (ESC) is an electronic device that receives signals from the flight controller and converts them into timed electrical pulses to control the speed of a brushless motor. When selecting an ESC, ensure that both your FC and ESCs are capable of running the same protocol, such as DShot 600. Additionally, the current rating of the ESC must be higher than the amperage drawn by the combination of motors and propellers.

An ESC typically has four input terminals, two for signals from the FC (signal and signal ground) and two for the power supply from the Power Distribution Board (PDB) (positive and negative). It also has three output terminals, one for each wire of the brushless motor. Some ESCs now offer telemetry, which allows for monitoring and data logging of the ESC’s performance.

Builders tip: If you are using an FC with an integrated PDB, all four wires going to the ESC will come from the FC. 4-in-1 ESCs are becoming popular as they can save weight, but they are not universal, so check compatibility before purchasing. If you’re unsure, it’s best to purchase a 4-in-1 ESC as a stack combined with the FC, such as the Holybro Kakute FC and tekkoS 4-in-1 ESC.

Note: The specifications of motors are usually provided under static thrust test conditions, which can be different from flight conditions. Propellers spin more easily in free air, which means motors use between 20% and 30% less current in flight than under static test conditions. If the maximum amperage draw of a motor is the same or just under the maximum current rating of your ESC, it should be fine.

Propellers

There are thousands of different types of propellers for quadcopters, with multiple options in almost every size. A heavier propeller will require more torque from the motor than a lighter prop. Also, blades with a higher Angle Of Attack (AOA), also known as “aggressive props,” encounter more resistance from the air and require more torque. When a motor has to work harder to turn, it draws more Amps. Finding a balance between the thrust produced and the amperage used by the prop and motor combination is a balancing act that every quad pilot goes through, there is no “right” answer.

Builders tip: Make sure that the props are tightened securely, a tool to grip the motors while tightening the prop nuts can be helpful. If the props slip, it can cause erratic behavior in flight.

Note: Props these days are generally well-made, but they may still be unbalanced. If you are experiencing vibration or ‘jello’ in your camera, check that your props are undamaged, unbent, and balanced, before you start disassembling.

Battery

LiPo (Lithium Polymer) batteries are commonly used as the power source in quadcopters due to their high energy density and high discharge rate. LiPo batteries are rated by their nominal voltage (3.7v per cell), cell count in series (indicated by a number followed by ‘S’ such as 4S = 14.8v), capacity in milliampere-hours (mAh, such as 1300mAh), and discharge rate or ‘C’ rating (such as 75C).

Builders tip: Keep in mind that the battery is the single heaviest component of your quadcopter, so a larger battery does not necessarily translate to longer flight time.

Note: It is not recommended to buy cheap “no name” batteries as they often have inconsistencies in cell voltage, inflated claims of capacity, and suffer from “voltage sag.” It is best to invest in reputable battery brands.

Camera

An FPV (First Person View) camera allows the pilot to see the view from onboard the craft, especially in mini quadcopters there are normally 2 cameras: one for real-time video streaming and the other for recording HD footage. FPV cameras are designed to have low latency and wide dynamic range (WDR) which is crucial for FPV. WDR refers to a camera’s ability to display changes in lighting conditions and areas of shadow and light in the same image. Latency is the amount of time between the FPV camera capturing the image and displaying that image on the screen or in the goggles.

The FPV camera connects to the Video Transmitter (VTX) often through the Flight Controller (FC) which then overlays On-Screen Display (OSD) information on the image. A camera usually requires 5v to operate, but some cameras are capable of a wide input voltage and can be connected to the battery voltage (VBAT).

Builders tip: If you experience interference in the FPV image when applying power to the motors, a capacitor can be used to filter the noise.

Note: Cameras transmit images in different aspect ratios (such as 16:9 and 4:3), make sure that your FPV display (goggles or screen) is compatible. Different signal formats are also used in image transmission (such as PAL and NTSC), and your FPV display must also be capable of decoding the relevant signal type. Nowadays, cameras are often able to switch between these signal formats and some can even switch between image display ratios.

Video Transmitter

A Video Transmitter (VTX) connects to the FPV camera to transmit video to the FPV goggles or monitor. Most quadcopters use 5.8GHz for video transmission. Some VTXs offer additional functions such as a regulated 5v output that can be used to power the FPV camera. Be aware that if you power your VTX without an antenna connected, it may burn out.

The VTX receives a signal from the FPV camera (often via the Flight Controller) and then broadcasts on one of the channels within the 5.8GHz frequency bracket. Some VTXs run on 5v while others require more. If your VTX runs on 5v, it will be active when you connect your FC to USB, so make sure to have an antenna connected when configuring BetaFlight. If your VTX requires more than 5v, it will not function with USB power and you will need to connect a battery to set up the channel, band, and output power.

Builders tip: If your VTX gets hot, it is a good idea to place it in a location on the frame where there is space for airflow to cool it down.

Note: When flying with others, be aware of your VTX power and make sure to check the frequencies being used by others to maintain good signal spacing.

Antenna

Every VTX requires an antenna to transmit a signal. Antennas come in various shapes and sizes, such as directional, linear, and polarized.

Builders tip: Keep in mind that carbon fiber material can block the 5.8GHz signal used by the VTX. Make sure that the antenna is far enough away from the frame to be able to transmit without the signal being blocked.

Note: If you are using polarized antennas, ensure that both the antenna on your VTX and the one on your goggles are using the same direction of polarization. Left-hand circular polarization (LHCP) works only with LHCP, and right-hand circular polarization (RHCP) only works with RHCP.

Optional Components

Additional components commonly added to a mini quad are LEDs and a lost model buzzer. These are especially important for beginners, as they can help locate the quad if it goes out of sight. Especially when flying FPV, without something to draw your attention, the quad could be lost forever. Another common feature is the Go-Pro or similar action camera, which allows pilots to share their successes and failures on platforms like YouTube.

Builders tip: Keep in mind that smaller quads are better at hiding in tall grass, so be sure to have a way to locate it if it goes out of sight.

Batteries are the power sources for quadcopters, and different types of batteries such as LiPo, Li-ion, and LiHv are used in FPV. To properly charge these types of batteries, a specific charger is required. In this guide, we will focus on the best LiPo chargers that we have tried and tested.

A typical LiPo battery, on paper, should last for around 200 charge and discharge cycles. While a 1500mAh, 100C battery can theoretically provide 150A of current (the current capacity of a battery is calculated by battery mAh/1000 multiplied by the discharge of the battery), these batteries cannot be charged at the same rate as they are discharged.

Batteries are delicate components and can be flammable if mishandled, so it’s important to be careful when handling them. The battery’s behavior, discharge current, and life cycle depends on how the battery is treated. For example, mishandling a battery by charging it at high currents can negatively impact the battery’s performance. This guide will explore the top chargers for batteries and how to properly care for LiPo batteries.

Terminology

There are a few terms you must familiarise yourself with before diving into the guide.

mAh (milliamp hour) is a unit of measurement that denotes the capacity of a battery. It is similar to the battery capacity of a phone, where a larger number means a larger capacity. However, higher capacities come at the expense of increased weight.

A larger capacity battery will increase the overall weight of the quadcopter, which can make it feel slow and sluggish in the air. On the other hand, smaller battery capacities will result in a lighter quadcopter that feels more agile and nimble.

C rating: A C rating is a measurement of the amount of current a battery can safely deliver. A higher C rating means a higher discharge current. However, the C rating has become a number used for marketing and manufacturers often make false claims about these numbers.

Connector: A battery connector is present on the battery and helps connect it to the quadcopter’s flight controller and provide power to it. The type of battery connector present on the battery depends on the voltage and current carrying capacity of the battery.

A smaller battery typically uses a JST or JST PH 2.0 connector, while slightly larger batteries use XT30 and XT60 connectors. These connectors are designed to handle the specific voltage and current carrying capacity of the battery.

Parallel charging wires, also known as balance charging wires, allow batteries to be charged by connecting them in parallel. This is commonly used when connecting multiple smaller batteries in series to make a larger battery pack. The balance charging wires ensure that each individual battery is charged independently so that the overall battery pack is charged evenly.

Battery charging current – This probably is one of the most important factors and calculations to be made before charging a battery without damaging the battery itself.

As a general rule of thumb, a 1C charging rate is considered ideal. 2C charging rates are also fine, but anything higher might reduce the battery’s life in the long term. For example- A 1500mAh 100C battery can be safely charged at 1C (1.5A) or 2C (3A). Any advanced chargers have the option to change the charging currents depending on the battery itself.

Factors to consider

Some major factors differentiate a charger that will last you a long time and a charger that will work for a while and die. Let’s find out what those factors are, continue to read below.

Number of Charging ports

Charging ports are similar to our wall sockets where we plug in our chargers. Similar to this, we plug the batteries into our sockets aka FPV charger ports. FPV Chargers draw power from the wall and charge our batteries at a controlled rate.

Since not all batteries are the same, by different I mean different capacities, and voltages, they would need different charging needs. FPV chargers with 2 charging ports which are essentially 2 chargers, can do just that- charge dissimilar batteries.

But do you need 2 charging ports? Maybe. FPV chargers are things that don’t get replaced often and tend to stay with us for years and are just as critical as a Flight Controller to ensure the batteries don’t get stressed. Not only do dual charging port chargers are expensive than single charging port chargers, but they are also quite bulky. Single port chargers like the ISDT Q6 are so small that they can be slid into one’s pocket.

If the upfront cost matters to you, then you could pick a single port charger and use a parallel charging board, more on this below, and charge multiple batteries from the same charger.

Max Charging Current

Max charging current means the max current a charger can provide. A bigger battery requires a larger charging current. In the world of FPV, the most commonly used voltages are 4S and 6S. For a 1000mAh 6S battery, the typical charging current at 1C is 1A and at 2C is 2A, the same goes with 4s batteries. So we do not require a large max current rating if you charge a single battery at a time.

We can charge multiple batteries at a time if the charger has 2 charging ports, but most chargers come with a single charging port. There is another way to charge multiple batteries from this single charging port- Parallel charging boards. More on parallel charging boards below.

Battery Type Support

The most commonly used type of battery is LiPo (lithium polymer) battery. But we do use other kinds of batteries like LiHv (High Voltage LiPo), Li-ion (Lithium Ion), and some ancient batteries like NiMH (Nickel Metal Hydride) to power other peripherals such as FPV goggles and such. Some people even use Lead Acid batteries to charge batteries on the field.

If a charger only supports one type of battery chemistry, you really would be bound to that type of battery chemistry. If all your charger support is LiPo, then you would have to use LiPo batteries to power your miscellaneous. But the downside to using LiPo is the lower cycle count (The charge and discharge cycle) typically 200 compared to the 600 of the Li-ion batteries.

Portability

Some chargers like the ISDT Q6 weighing in at a mere 100g are so small that they fit into your pocket and some chargers like the SkyRC Q200 charger weigh at a not-so-light 1.3kg or just over 45 ounces. Portability matters when you have a small workspace or you plan to field charge your batteries.

But the Q6 (on the left) and the Q200 (on the right) are chargers of 2 different spectrums. The Q6 does not come with an integrated power supply, while the Q200 comes ready out of the box meaning to say it can be plugged into the wall socket out of the box with no need for external power supplies and other hassles.

Are you saving up space by buying a Q6? Probably not, as the size of the Q6 with a power supply comes to more or less the size of the Q200. But why buy a Q6? Because of the cost, while the SkyRC Q200 costs $175 the Q6 ($60) with the power supply ($24) comes to around $84 which is less than half of what the Q200 costs.

Max Voltage Support

Max voltage support is the maximum voltage that the charger can charge. Mostly we use a maximum of 6s batteries i.e. 22.2V. Most professional-grade chargers support up to 6s batteries and you should be good.

Some basic chargers like the one on the left might support a maximum of 4s and if you ever decide between advancing through the hobby and switching to 6s you will have to shell out extra cash. A disadvantage to these types of chargers is that they are inaccurate to some extent and they do not offer the users the option to tweak the input current and the option to discharge the battery.

Parallel Charging Boards

I probably mentioned parallel charging boards a dozen times already. What are parallel charging boards? Parallel charging boards are components that help to charge multiple batteries from a single charging port. Not all chargers have multiple charging ports and charging 10 batteries requires a lot of time (roughly an hour per battery) from a single port. Hence we have parallel charging boards.

The parallel charging board works by splitting the current coming from the charger to all the ports on the board. For example, if a parallel charging board has 5 ports and 5 batteries are connected, then the current coming from the charger is divided into all 5 ports.

But there’s a small catch to it. Only batteries of similar voltages and capacities can be charged together as the charger views all 5 batteries as 1 single larger battery. If batteries of different capacities are connected, then the battery with a smaller capacity might get overcharged and get damaged in the process.

POWER SUPPLY BASICS

Traditionally we are used to taking any charger, our phone charger for example, and hooking it up to the wall socket and expecting the phone to charge. That should be the same case with FPV chargers right? Well, kind of. Some chargers come with integrated power supplies, some don’t.

As mentioned earlier, Chargers like the ISDT Q6 pro or the Q6 plus do not come with a built-in power supply and need an external power supply to provide power to the charger. Now let’s talk in more technical terms. Every charger has something called a power rating. The ISDT Q6 is rated for a maximum power of 300W (spelled as 300 watts). Power is the product of voltage and current.

Power (P) = Voltage (V) x Current (I)

To exploit the full potential of the Q6, the power supply must be able to provide at least 300W of power. A power supply generally has a fixed voltage and a maximum rated current. For example, if a power supply has a fixed voltage of 12v and can provide a maximum current of 10A then the power rating of the power supply is 120W (12v x 10A). Suppose the maximum current was increased to 20A then the power rating is 240W (12v x 20A).

So we can just buy a 12v 30A power supply and be done with it right!! No. To higher charge voltage batteries, 5s or 6s then a 12v power supply would not be sufficient. But, a 24v power supply can provide 300W of power with a current rating of 12.5A.

Also, higher current-rating power supplies require beefier internal components and tend to be more expensive than lower current-rated batteries. Hence as a general rule of thumb, a 24v power supply with at least 10A of current rating would work well for most setups.

Our pick for a power supply

FIELD CHARGING BATTERIES

Field charging batteries might be one of the most practical and cost-effective approaches to flying longer in a single flying session. Of course, you can buy lots of batteries to fly without having to wait for batteries to charge but then again, a 4s battery costs $40 and buying 20 batteries easily pushes the investment on batteries to $800 alone, with a good spaced quad costing around $250.

With advancements in technology taking place every day and better batteries being developed, the technology available today might be outdated 1 year down the line. Hence a significant investment in an immature system is not recommended. Hence buying a small number of batteries often is a wiser choice.

There are many ways to charge a battery on the field. Some methods include buying a large 4s or 6s 20,000mAh or higher capacity battery. This is the most practical and viable approach. Field charging is a lot safer than charging the batteries in your home, as you don’t have to worry about the batteries exploding or catching fire.

The Energy Density of the larger battery plays a role in how much smaller batteries can be charged. A 6s 20,000mAh battery has an Energy Density of 504Wh (25.2 x 20) and a 4s 1500mAh battery has an Energy Density of 25.2Wh (16.8 x 1.5). So technically a 6s 20,000mAh battery can charge 20 (504 divided by 25.2) 4s 1500mAh battery.

Another method would be to use a mini generator to charge the batteries, but a generator costs a lot of money with a decent generator costing around $950 from Honda, and tend to get noisy. Some people use their car batteries to charge their LiPOs. But if the car battery is discharged enough, then you won’t be able to start your car and will need some towing.

Conclusion

FPV chargers are long-time investments that stick around for a while and investing in a good quality FPV charger would benefit the user in the long run and eventually save money. A bad FPV charger cannot charge your battery and will slowly damage batteries and kill your investments slowly. Lastly, if you plan to field charge batteries you will just have to charge one larger battery and go to the field rather than buying a generator and worrying about lugging that thing around.