Why are drone flight times so short? [SOLVED]

There is one thing about flying a drone that is very frustrating – just as you are getting into the swing of things you have to land because your battery has run out of power. There is no doubt that battery technology has come on leaps and bounds in the past few years. But, there is still something missing when it comes to battery technology which means that the average flight time is somewhere between three minutes and 30 minutes. This all depends on the sort of drone that you’re buying – the cheaper the drone the less flight time you can expect.

Drone flight times are so short because there needs to be an intricate balance between the power and weight ratio of the drone. The lithium polymer battery technology which keeps the majority of drones in the air are much better than lithium ion batteries (as they are much lighter) but they need special care and attention – and still only carry a certain amount of energy to power the flight. Drones are energy hungry devices which need a fast discharge rate battery – and technology hasn’t quite caught up with the way that we want to use our drones.

In this article – we’re going to go over the reasons why drone times are so short and what you can do to increase the amount of flight time you get from your drone. We are still waiting on the next eureka moment for drone batteries but in the meantime there are some tips and tricks that you can employ to keep your drone flying for longer.

Let’s get into it!

Short flight times for drones

If you are experiencing significantly short flight times for your drone this could signify that your battery is becoming degraded with use or it may also be an indication that your flying style is too aggressive. However, there are just some things you can’t control such as the weight of your drone which will dictate the way to power ratio that your battery is able to provide. If you are building your own drone you can swap out the battery for a higher capacity battery but this will increase the weight. If you are the owner of a commercial drone you probably cannot swap out the battery and you will have to rely on other techniques to extend your battery life.

Weight power ratio

Lithium polymer batteries were an important advancement in battery technology for drones. Before this we were limited to the lithium iron batteries – the same that you’ve got in your computer laptop – these are much heavier and have a much lower power to weight ratio than lithium polymer batteries.

These batteries offer the best combination of weight and energy density. Each individual lithium polymer battery is made up of individual cells. The one in your drone has between one and eight of them. Each of the sales are rated at 3.7 V and are fully charged at 4.2 V.

The lithium polymer batteries require very special treatment and if you let the battery drop below 3.7 V you will permanently harm the battery. This means that many drone enthusiasts damage their drones without realising it. You can simply forget to charge your drone for a few months and the battery can be a repairability damaged.

Power hungry components

Drones are very power hungry beasts.

If you think about all of the advanced software programming as well as the hardware that drones are running while in the air it can be amazing that they take off at all.

You see drones are running components like:

• inertial measurement units
• motors
• GPS units
• electronic compasses
• barometers
• lights
• cameras
• accelerometers
• gimbals
• and lots and lots of computational power for running artificial intelligence algorithms.

Also, as the electricity flows through the drone there is a reduction of the power efficiency due to the generation of heat as the circuit conducts the electricity quickly to the components that needed the most.

Smart batteries discharging during storage

Another reason why drones have a short flight time is due to the way that the manufacturers are programming their smart batteries.

Because lithium polymer batteries are very temperamental in terms of how they should be stored, manufacturers allow them to make some decisions about their discharge during storage.

A lithium polymer battery should not be stored at 100% charge. Instead, it should be charged at somewhere between 30% and 50% of its maximum charge. This ensures that the battery lasts for as long amount of time as possible during storage.

The smart batteries will discharge themselves until they reach about 30% of their storage capacity. This means that if you haven’t freshly charged up your battery before a drone flight the battery will have discharged a little bit to a lot depending on how long it has been since its last charge. This means that your drone may not reach its full flight time if the batteries have been self discharging during transport and storage.

An easy way to get around this is to make sure that your drone batteries are charged freshly for each flight. You can even buy in car chargers to ensure that there is not a moment’s delay between charging and flying. This will increase the flight time of the drone.

Bad battery maintenance

You may also be inadvertently damaging your batteries so that they don’t last as long. Lithium polymer batteries need to be kept clean and dry and allowed to be fully cooled before charging.

And the transfer that energy into the drone causes the drone and the battery to heat up significantly. You should always allow your batteries to cool off before recharging to maintain their maximum efficiency.

There is also some discussion of cycling your lithium polymer batteries for their first use. If you have purchased a new battery you can cycle the battery a couple of times to help increase the longevity of the battery. after an initial couple of cycles, you can repeat this every few months. That is combat something referred to as “battery memory” where the battery remembers how far it was last discharged and causes it to artificially shrink its capacity.

Aggressive flying

Lastly, your drone may not be lasting as long in the air as you want it to because of your flying style. Aggressive flying styles will mean that the drone is using a lot of energy to overcome its own momentum while changing direction or slowing down.

This can be compounded by using a sports mode on your drone which will cause the drone to move at maximum acceleration upon movement of the joysticks.

If you want to know why your drone battery die so fast check out my other article where I go through everything you need to know about looking at your lithium polymer battery as well as a guide to longer flights – click here to be taken to article.

Also, watch my YouTube video below:

What is the average flight time for a drone?

The average flight time of a drone very significantly as well as the capacity of the battery. In the table, below, I have listed some of the most popular drones currently available and the flight times of each of the drones. Take note that these flight times are that stated in the specification sheet by the manufacturer. Typically, these are in a hovering position with no wind to compensate for.

Table of common drones and their flight times

The average flight time of these drones is: 31 minutes.

Obviously, this average flight time is dependent on a variety of variables which can significantly impact the flight time of a drone.

What is the maximum flight time for a drone?

One of the longest flight drone times ever recorded is four hours and 40 minutes. Given that the average drone can only hover for only half an hour this is pretty impressive. This record is claimed by Spanish drone manufacturer Quaternium. The drone uses a hybrid fuel source which includes an electric engine and a combustion engine. The combustion engine keeps the battery charged throughout the flight.

The company’s mission is to:

Quaternium mission is to design the most advanced multirotor UAVs in the market. We combine experience and high tech to develop a disruptive product that aims to revolutionize the multicopter field. With this ultimate innovation, flight duration is increased 6 times compared to existing alternatives.

That’s pretty impressive and it’s something that they seem to have been able to achieve. One of the current models of drones involves a two-stroke combustion engine that requires a 95 octane +4% oil mix. It also contains a lithium polymer battery. It can carry up to 10 kg and at a full load can stay in the air for approximately two hours. The cruise speed is 50 km/h with a maximum speed of 80 km/h.

That’s a pretty impressive drone that has a load of potential applications where lithium polymer batteries alone will not cut it.

How can I make my drone fly longer?

If you want your drying to fly longer there are number of things you can do to extend the flight time. We’ve already covered some of them in the first video but here are the elements which you should look into to extend the flight time.

Reduce Weight

Have a look at your drone and make sure there is no excess weight. Even if you have got custom decals or other stickers on the drone you could be increasing the weight to the point where the drone has to spend a little bit more energy staying in the air.

Perhaps you are using your drone for fishing or other carrying purposes – making sure that you minimise the amount of weight that you are carrying will extend the drone life significantly. If you want to know more about drones that can carry things check out my other article where I go through all of the innovations and drones that are specifically designed to carry items – click here to be taken to article.

Battery health and maintenance

Taking good care of your battery and making sure that it is stored in the appropriate way will mean that when you come to your flight your drone will be in the best condition possible for extending your flight times.

Here are some simple tips that you can use to keep your drone batteries healthy:

• keep them clean and dry – store your batteries in a clean and dry area which has now moisture or access dust. If battery comes into contact with moisture it can corrode the electrical contacts. You can clean off some of the corrosion with isopropyl alcohol if you find some.
• Store at 30 to 50% charge – never leave your drone battery is fully charged if you’re storing for long periods of time. The short term storage your battery should be discharged to between 60 and 80%. And for long-term storage (more than 10 days) you should store the battery between 40 and 60%. Battery should not be left for over three months they be in charge as the battery life will be significantly reduced and may be completely damaged altogether.
• Store in a cool spot – storing your batteries in a cool spot will mean that they are going to escape the extremes of heat experienced if you were to leave them on a windowsill et cetera. The lithium polymer composite inside the battery is heavily affected by heat and if you live in a hot climate be sure to store them sensibly away from extreme fluctuations of heat.
• Freshly charged batteries – just before you’re about to fly make sure that your drone batteries are freshly charged for your flight. This is one way that you can ensure that your drone batteries are carrying the maximum amount of charge for your flight.

Carry more batteries

It’s an obvious one but by carrying more batteries for your flight mission you will be able to spend more time in the air. It’s a simple solution to a common problem and all it takes is a little bit of a budget for a second, or more, battery.

Carrying another battery also means that you can be flying whilst charging up one of the spares. Just be sure to completely allow the drone battery to cool before recharging it.

Fly on calm days

another way to make sure that your flight times are increased is to choose days where there is not a significant amount of wind or other environmental factors which your drone has to fight against. If you have a flight mission where you are against the clock waiting a day for the winter die down may be the best way that you can be assured that your flight mission will go as planned.

I like to land with at least 15% battery remaining which means that if there are any last-minute issues I can safely return to my landing spot and not land short. Sometimes the wind direction can change which means that your drone has to work harder against the wind to get back to the landing spot. The extra 15% battery means that you have an error bar to save you.

Plan your flights

Lastly, make sure that you plan your flights well. A lot of flight time is used up covering distance which you don’t need to. Also, if you have not run the drone recently you should turn the drone on at home so you can check for any updates which may take up precious battery time before your flight.

Making sure that your flight plan makes the most efficient use of your battery will also mean that you get more done in the precious lifespan of your battery.

Battery research – drone futures

What does the future of drone batteries look like? given the recent advances in lithium polymer battery technology it’s hard to imagine what the next stage will look like. Maybe it will be a battery innovation or, it could be something else. For example, we could see a mixed fuel cell dominate the market like in the video in this article.

In the scientific literature at the moment we are seeing a lot of talk about wireless drone charging stations. This means that the battery technology does not change but rather the way that the drone is charged during its flight changes dramatically.

Wireless drone charging stations

A study published in 2016 gives us an idea as to what this technology may look like. The team manufactured a Quadro to drone wireless charging station. The station detects the drone with ultrasonic sensors and consequently scans it with a pair of lasers to determine its central coordinate.

During the wireless charging the electrical current provided by the receiver was 30 mA with a voltage of 5 V which is approximately 65% of that that you can get through charging with a wire. The average charging time was 75 minutes in contrast to the 50 minutes required for wire charging.

This technology will need significant research and investment before it becomes a commercially viable alternative to charging your batteries via a wire but there has been talks about using wireless energy transfer to charge drones while they are in the air.

We will have to wait to see what the future holds…

The final word

Drone flights are so short because of the limitations of the lithium polymer battery as well as the power to weight ratio that these batteries are able to achieve. The average consumer level drone flies for approximately 30 minutes which is significantly better than it was about five years ago.

You can also increase your flight times by reducing the aggressiveness of your piloting whilst also taking into account your flight plan and drone weight.

There is no doubt that there is some exciting technology in the future – we just have to wait to find out what that looks like.