There’s More Than One Way to Power a Drone, Which Way Is Best for You?

From solar, laser, and wind to batteries, hydrogen, and even jet propulsion, a number of solutions can get your drone into the sky. Some of these technologies have been around since the drone industry began, but there are also new and innovative options being developed all the time that are enabling longer flight times and heavier payloads.

With all of the powering solutions out there, it can be a challenge to decide what is best for your needs in terms of endurance, longevity, cost, and efficiency, especially as drone operations become more complex and move beyond visual line of sight. End users have to answer questions like how long do I need to stay in the air in order to recoup costs? What kind of weather am I likely to encounter? Can I afford to ground my fleet if they can’t handle certain conditions? What is the weight of my payload, and how much energy will it consume?

The answers ultimately come down to physics and the bottom line. You need the right powering solution to get your aircraft into the air, doing what it needs to do within the time and conditions it needs to do them in, while carrying the necessary payload it was intended to carry at a cost that enables a return on investment. This can be a tall order and there are a lot of powering options out there to weed through, which can be daunting.

For this two-part series, Commercial UAV News is breaking down the various powering solutions out there to help new and experienced drone users alike understand what is available today and the best use cases for each option out there. To do so, we reached out to seven different companies that specialize in powering solutions for drones from small and mid-sized to heavy-lift cargo to obtain their expert insights on what makes these powering solutions run, their capabilities, what they are best suited for, and more.

We have split the series into two categories, small to mid-sized and mid-sized to large/heavy-lift drones, as these classes of drones tend to be used for different purposes within the commercial drone space. For this first part, we will focus on powering solutions that are compatible with small to mid-sized drones. Although most of the companies covered in Part 1 are also capable of providing solutions for bigger drone solutions, those in the Part 2 of this series are usually only used for powering larger drones.

Rose Batteries Custom-Built Battery Solutions

If I were new to your powering solution, how would you explain it?

Itamar Frankenthal, CEO of Rose Batteries: When you start at the consumer level of drones, they’re typically using polymer batteries (Li-Po or lithium polymer batteries) because they are very light. However, the problem with polymer batteries is that they don’t scale well into larger batteries—and the reason for that is the underlying cells. These cells were originally made for single cell applications such as cell phones, where cells do not require to be matched as they are in single cell packs. Therefore, the manufacturing process leads to inconsistencies from one cell to the next, and you are only as strong as your weakest link. With polymers, because they are inconsistent from one cell to the next, they don’t balance well, and they age at different rates. So, as you use your battery more and more, it actually degrades much faster, and they are just not as reliable in terms of consistency of power. 

Think of it like putting tires with different treads and sizes on your car, that may work for a while but it is not good for longer haul operations; this is the same for drones as uses become more industrial—they need more consistent cells in order to provide either a longer flight duration or be able to lift bigger loads.

To best support multi-cell packs, this requires cylindrical or can cells (i.e., 18650 or 21700 cells) instead of polymers. What this means is you are now shifting your chemistry from a polymer chemistry, or Li-Po, to lithium ion. Once you start working with cylindrical cells, you need an assembler such as Rose to help you select the right chemistry and the right supplier; help you develop the BMS (battery management system); design a thermal runaway shield using patented materials; help with the required regulation requirements that come with larger energy batteries, including transportation, testing, and custom packaging; and finally to help with ensuring the safety necessary for mission critical applications where failure is not an option. 

What are the key differentiators of your solution from other options out there?

Our number one differentiator is our engineering design capabilities, including the ability to provide sophisticated, custom BMS designs. Number two is our many partnerships with tier-one cell manufacturers, which provides us access to confidential cell performance datasets and the ability to procure the cells with the manufacturer’s warranty.

Most of the battery industry has grown up working on high-energy applications—that is how far or how long the battery can last (think the size of your car’s gas tank)—instead of high-power applications, which is how much muscle it has (think of your car’s horsepower, torque or acceleration). Drones need to be able to have the thrust to deal with heavy loads, starting torque and gusts of wind. Most of the industry does not have the level of experience that we have in dealing with high-power applications.

The third differentiator is that we have years of experience with batteries for FAA applications and FAA Type Certifications. As drones become more commercial in their nature, working with a partner that understands and knows how to work with the FAA, or at least those applications and certifications, becomes critical.

The fourth and last element is safety. There are a number of patented technologies available including phase change material, or PCM. PCM is a safety feature that stops thermal runaway. In other words, if one battery catches fire, they don’t all catch on fire.

What kind of operations are best suited for your powering solution?

Our batteries are mainly used for industrial, medical, oceanographic and military operations. We currently build batteries for drones that operate on air, sea, and land. We are seeing high growth in batteries used for medical and commercial delivery systems.

What are some of the challenges your powering solution is currently working on solving or has solved?

Beyond the standard runtimes and payload capacity, another challenge is how to design the BMS to be able to support the high current in-rushes that are necessary for high thrust environments, while at the same time being able to detect and shut down in a short circuit environment.

The question is, “How do you design a board that is smart enough to differentiate between a high thrust environment where you need a high current, and a short circuit environment where you want to cut things off?” This was a unique technical challenge that we have solved.

Likewise, the same challenge exists with a low voltage cutoff. When you go beneath a certain voltage on a battery, you start damaging the battery to the point where it becomes a safety issue. If you deplete your battery too much, it is called over discharge, and the safe thing to do is to retire the battery. The flipside of that is if you have a drone in midair, cutting off the power due to low voltage could be catastrophic. So, again, how do you deal with low voltage safety cutoff of the battery, while at the same time not having a premature termination of a mission?

These are the kind of technical challenges that we work on and solve for customers to ensure the long-term safety and health of the battery. 

If someone is interested in your solution what can they do to learn more?

They can check out our website at www.rosebatteries.com or reach us is at [email protected]. 

WiBotic Wireless Charging Stations

If I were new to your powering solution, how would you explain it?

Matt Carlson, VP of Business Development: We’re a little different because we don’t provide the batteries, but rather offer smart wireless battery charging. Our founders developed the technology at the University of Washington and were looking for ways to bump up the power level but also give a much broader range between antennas. Drones and robots are just not that accurate in how they dock or land at a charging station, so you need the flexibility of positioning to be able to effectively charge at full power every time.

To do this, our system has four main components: a transmitter box that plugs into the power source, which can be electric or solar, AC or DC. The transmitter has a standard antenna that is about eight inches in diameter that sends out a wireless power signal. On the vehicle, there is about a four inch in diameter antenna that receives the wireless energy and sends it down a short coaxial cable to the onboard charger. Antenna sizes and shapes can be customized if needed.

As soon as the drone lands, our transmitter sends out a handshake signal to find out how much power is needed. The onboard charger is really the brains of the system though. It is programmed for a particular battery voltage and current (charge rate) but those parameters can be adjusted at any time using our APIs. For instance, the drone may request 200W of power to charge quickly before its next flight, or it may slow the charge rate to 100W if another flight is not imminent. The onboard charger is also programmed for the correct battery chemistry. Most drones use Lithium Polymer batteries, but many other chemistries are supported. 

This level of programmability is important for battery health, safety, and longevity. For example, if you repeatedly charge a lithium battery to 100% and then discharge it to its minimum, that is one of the worst things you can do for the overall lifespan of that battery. Our wireless charger gives you the control to charge quickly and to full capacity when needed, or to slow down and stop short of 100% when not needed. This allows customers to make informed decisions about how an entire fleet of batteries can be managed to reduce failures and replacement costs.

What are the key differentiators of your solution from other options out there?

One of the key differentiators is that our system is fully designed, manufactured and ready for installation on any drone. Most of the other solutions in the autonomous charging arena require a lot of work on the customer’s end to fully integrate the system into the drone. If you want to quickly retrofit a drone so it can autonomously charge, or if you are a manufacturer of drones and don’t want to spend the time designing new circuits, you can buy our components and implement them with minimal effort. We have a mechanical engineer on staff who can also help with mounting brackets for the components if needed, so we try to make this as turnkey as possible.

Another differentiator is that, because it is wireless, you can fully seal a landing pad for outdoor use. Other autonomous charging solutions use metallic contacts or surfaces. If those elements get wet or corrode out in the weather the systems become less reliable. But with wireless charging, you can make a plastic landing station that is fully sealed to the elements.

What kind of operations are best suited for your powering solution? 

Our solution is really perfect for repeated flights from either a single location – say from a rooftop, a mounted station on a truck or other mobile device, or a series of landing pads along a route (like a pipeline, energy lines, or railway) which can extend drone range for long autonomous flights.

The whole idea of wireless charging is to remove the need for a human to have to manage battery charging. If you have a drone that can fly itself but can’t recharge itself and do it again, you’ll spend a lot of money having humans onsite to execute those flights. Our solution is best suited for missions that are trying to remove the human element from the charging process so they can focus on mission planning and data analysis.

There are a number of applications for this technology. One has been in the energy industry to do things like repetitive infrastructure inspections facility surveillance, and even methane detection. Other applications have been in agriculture for daily crop monitoring and in public safety where having a drone always charged and ready to deploy from a fire or police station is critical. In construction we see drones flying several times per day to document progress, take inventory of materials, or to ensure worker safety.

What are some of the challenges you are currently working on or have solved with your powering solution?

One of the challenges is that precision landing is still needed as a technology on the drone. The drone needs to be able to make it back to the landing pad and reliably set down on it. We provide range flexibility on the order of several centimeters in any direction, but the drone can’t land three feet off the pad!

Most of our customers have implemented a precision landing system. Depending upon how accurate it is, they may also use a secondary mechanism to capture and center the drone for charging. Unlike the cell phone wireless chargers most people are used to, though, our technology does not require perfect millimeter-level alignment. If the drone is within several centimeters of its target, full power and efficiency is achieved.

We’ve worked with some very good precision landing systems that we’ve integrated on behalf of customers. And this is also getting solved by the drone manufacturers themselves. A lot of them are working on better precision landing capabilities on their own, but it is still one of the challenges we have to keep in mind when working with customers.

What is the price range of your solution?

WiBotic has a range of products with different size, weight and power levels, so we work with customers to determine which configuration works best for them. Generally speaking, though, our systems will be in a similar price range to other high-quality accessories you might purchase for commercial drones. We also offer ongoing maintenance, support, and cloud-based data monitoring for remotely deployed drone charging stations – and volume discounts are available for OEMs and those end users who are beginning to deploy larger drone fleets. For fleet deployments we also offer a monthly service-fee based pricing model.

When you consider that our technology eliminates the need for human battery swapping, increases battery lifespan, and can increase the range of a single drone by enabling movement from landing pad to landing pad, there is just a tremendous amount of a value for the customer.

If someone is interested in your solution what can they do to learn more?

You can email us directly at [email protected] or visit our website www.wibotic.com.

HYBRiX 2.1’s Hybrid Electric–Combustion Engine

If I were new to your powering solution, how would you explain it?

Gregorio Centurion, Marketing Responsible at Quaternium: Drones started being powered by combustion engines, like traditional aircrafts. But combustion power requires big engines and therefore you need to have a bigger drone, which is not so accessible. There was a boom in the market with the popularization of electric batteries because it enabled drones to maintain a compact size and be more accessible to the public. But by using batteries, flight time was drastically reduced down to 10 to 20 minutes. HYBRiX is an innovation, inspired by hybrid cars, that combines the best of both technologies. Making it possible to carry a very small engine while multiplying the flight time over 1,000%. And it introduces redundancy on the power system. If the engine stops for any reason, the aircraft can still land on electric-only mode.

What are the key differentiators of your solution from other options out there?

Nowadays, most multicopter drones in the market offer flight times ranging from 20 to 30 minutes, forcing the pilots to carry multiple batteries to the field and lose most of their time charging them. Compare this tedious work with just spending the whole time flying and getting all the information you need. With this game-changing innovation, it is possible. HYBRiX is the best cost-effective solution in the market, it provides a highly valuable solution for customers who cannot afford a manned helicopter but need more flight time than current multirotor drones can offer.

What is the maximum flight time of your solution?

This World Record of 8hr 10 min. flight time, was possible with an experimental version of our drone HYBRiX 2.1, of 25 kg MTOW. HYBRiX commercial UAV has 4hr. of max. flight time.

What is the maximum payload your powering solution can support while maintaining optimum flight time?

HYBRiX needs to always fly in hybrid mode for optimum flight time, with a max payload of 5kg for the standard version and 10 kg for the heavy-load version.

What kind of operations are best suited for your powering solution?

Surveillance, monitoring, or first response missions are a perfect fit for HYBRiX. Its compact, smart and advanced design allows you to fly for more than 4 hours with maximum payload and react to critical situations. HYBRiX permits the user to cover large areas, and by pairing it with the NUNTH Gimbal with an EO/IR camera you can get images with 30x zoom and track moving objects during the day and night. This gives you the freedom to place your drone at a strategic point and detect something like a moving car (4.2m x 1.8m) from a distance of 5km.

Nowadays, electric drones are used to help rescuers in natural disasters to search the land and identify as many people as possible. Although they are useful, they all had the same limitation, flight endurance. Being only able to cover small areas. During these situations, every second counts. This is what motivated Quaternium to develop a drone that could have much longer endurance. These qualities make HYBRiX perfect for rescuers and firefighters enabling them to identify hot spots and access property damage while searching for survivors. Thanks to the unique features of HYBRiX, these situations can be managed safely while achieving faster results.

What are some of the challenges you are currently working on or have solved with your powering solution?

One of the key challenges, when you start working with a two-stroke engine on a small drone, is to reduce and control vibration with a very smart airframe design, so that it does not interfere with the delicate electronics onboard.

Getting enough power from a small range-extender, without losing reliability, is also crucial. And of course, if you have a 20 to 25 kg MTOW vehicle aloft, the level of quality and reliability needs to be high enough to ensure safety. Most multirotor drones are made out of hobby components, which do not meet the quality requirements for this type of aircraft.

Our team has made a great effort over the past 6 years to develop a high-quality solution with an outstanding performance to meet the high requirements of hybrid technology.

What is the price range of your solution?

HYBRiX is an aerial solution for professional applications, which means pricing is defined based on the specific setting and intended application. When we receive an inquiry, our team assesses the requirements and then provides a proposed solution.

If someone were interested in your solution what can they do to learn more?

Quaternium ́s HYBRiX long-endurance solution is already available worldwide. For more info about the HYBRiX system, please visit send us a contact form from our website ​quaternium.com.