With winter now here in the northern hemisphere and many new drone owners taking to the skies with their holiday gifts, we thought it might be helpful to provide some tips and advice on using drones in cold weather. Cold has a major impact on how these aircraft fly so there are a few key items that should be kept in mind for winter use.
The number one issue with cold weather and drones is the impact it has on the batteries. As we have written before, the LIPO batteries used in most UAVs have a chemical makeup that slows in lower temperatures, which in turn reduces the power delivered from them and overall capacity and flight time.
Make sure batteries are fully charged before flight, you don’t want to use a partially charged battery in cold weather, where flight time is already reduced.
Keep the batteries in a warm location before use, DJI recommends having them at 25C before flight. Warm them in the car or store them in a small container such as a cooler with hand warmers, hot water bottles, heating bags, or similar to help maintain the temperature. Be sure to monitor them to ensure they do not get too hot or become wet in the process.
Sticking a spare battery in the inside pocket of your jacket can also help keeping them warm from body heat. DJI also makes battery heaters for some of their systems which can also be a convenient solution, although they do use a small amount of the batteries charge to run the warmer.
Many consumer drones have the battery mounted inside the main body of the drone itself, which helps protect it from the elements. However on larger systems and others with exposed batteries, wrapping them in a layer of foam or thermal insulation can help to maintain the temperature of the battery in flight.
Let your drone acclimatize to the conditions before powering it up. The on-board sensors can fluctuate with rapid changes in temperature. If taking the drone from your warm house or car to the cold outside there will be a period where it needs to adjust. Giving it 5 mins or so can help the sensors better stabilize before powered up and initialized.
On systems that have built in battery monitoring you may receive warnings and other messages due to cold. If cold enough the DJI systems for example may prevent arming and takeoff. While in flight they may also reduce maximum power so as to protect the battery from damage. These warnings typically happen when the battery is below 15C.
When you first takeoff hover the drone for a few minutes before pushing it harder. Once is use most batteries will generate enough heat from use to keep them warm, so an easy startup process will help generate some initial heat in the battery.
While in flight keep close attention to your screen and telemetry to the battery voltage and estimated percentage remaining. It will be reduced in the cold so this info can help to ensure you don’t push things too far. Plan for shorter flight times for your cold weather missions and give yourself a little added buffer.
Before recharging depleted batteries let them warm to room temperature, you want to avoid charging an overly hot or cold battery.
If there is moisture in the air, especially if the temperature is around the freezing point you may experience icing on the props. This buildup can lead to reduced performance, higher battery drain, and potentially loss of control/crash if severe. Be sure to keep an eye out and do a short test-flight to check for possible icing.
The moisture and cold can also impact the camera lens. Fogging or condensation can form especially when it is undergoing a change in temperature going in or outside. Letting it acclimatize can often resolve the issue.
Using a takeoff mat/pad is also a good idea to avoid snow being blown on and into the drone and camera if you don’t have a clear takeoff spot. A simple door mat or similar can make an easy to transport landing pad, just be sure it doesn’t get blown up from the prop wash of the drone, especially with larger systems, weighting down the corners can prevent this.
Also be aware of the impact of the cold on your phone/tablet, which use similar lithium batteries as drones. These devices are impacted in much the same way by cold as the drone and can shutdown if they become too cold, and battery life will also be reduced. Keeping the device warm & fully charged before use can help prolong battery life. A protective case can help limit direct exposure to the elements as well. Hand warmers can also be used to warm the device, but take care not to overheat or leave in contact for extended periods.
Keeping yourself warm is also important. Standing in one spot with little to no movement can quickly make your feel the cold. Be sure to wear warm clothes and boots. Flying with gloves on can also be a challenge. The loss of the direct feel of your fingers on the controls can make it more difficult especially for fine small movements. Using thin gloves can help although often times we go bare handed as the loss of touch is not ideal in many situations. Keeping hand warmers in your pockets can help bring frozen fingers back up to temp. Sunglasses can also be key to help prevent glare from snow which can be an issue on a bright clear winter day.
The use of gloves may also impact touch controls on tablets and phones used by many systems. Tablet friendly gloves with resistive touch features can help with this issue and are also fairly thin which helps address the stick feel mentioned above.
Radio covers/gloves can also be used and are fairly effective in keeping your hands and the radio protected from the elements.
The cold weather also makes the plastic material most consumer drones are made from brittle, including the props. What may seem like a minor “hard landing” in warm weather could result in breaks or cracks in the cold, so be sure to closely inspect the system after even a minor tumble.
After use make sure to store your drone and batteries at room temperature in a dry location. Remove any snow or other condensation that may have accumulated on it.
Winter can be a great time forgetting unique aerial images with your drone, just take the proper precautions and planning to do it safely & successfully. Have fun, fly safe, & stay warm!