Battery life is a constant worry for those who operate UAVs. Whether it’s a large, industrial, and long-distance flier or a small recreational model, the first question when planning a mission is always: how much energy is there and how far can I fly?
What’s more, during the mission, the parameters might change. A sudden change in the weather conditions, unplanned weight being carried by the drone, last-minute decision to record the flight draining additional power, etc. With all that in mind, it’s easy to understand why range and battery life are always top of mind for users.
Batteries can drain much faster if they’re not looked after properly. Manufacturers’ instructions should always be followed. But there are also some additional steps that can be taken to preserve battery life for as long as possible.
Take it seriously
Between 2012-2017, the U.S. Consumer Product Safety Commission received reports on more than 200 incidents involving drone batteries from 100 emergency rooms. They listed fire, overheating, melting, smoking, and explosion as the reason for the emergency room visit.
UAV batteries are not your regular AA type, so they need to be treated with much more care. So the main piece of advice will always be: read the manual. Seriously.
Consider the temperature
Extreme temperatures will drain batteries faster (some people keep their drones in their cars, which is a bad idea in hot weather). The hotter you make your batteries, the shorter their lifespan will be, so store them at room temperature. What’s more, remember to never change batteries that are still warm from usage. Wait until they cool down. And don’t use batteries that are still warm from charging.
At the other extreme, a rather common belief is that keeping batteries in the fridge slows down chemical reactions and, therefore, battery deterioration. But this can cause condensation to build up on the inside of the battery. And considering how volatile UAV batteries can be, this is a serious risk. Additionally, flying below 14°F (-10°C) is not recommended.
The right tools
Use an appropriate battery balance charger/discharger. If you want to use just any battery charger with LiPo batteries (most used in UAVs), go back two sections of this blog. And take it seriously.
But apart from being dangerous, this is also a bad idea because the battery and the charger are not compatible. LiPo batteries have several cells that have a very specific voltage range, and it needs to be maintained across all cells at all times. Cells whose voltages differ from each other can become unstable. It’s only appropriate to ignore the cell balance in one case: if you only have a single-cell LiPo, there are no cells to balance.
When flying in cold weather, consider investing in battery heaters to warm them up before flying. Regardless of how well you prepare and warm the battery each time, cold conditions will drain it extremely fast.
Storing the batteries is not as easy as it might seem. There are several rules to remember if they are to remain safe and keep their life span from shortening.
- Disconnect the batteries from the UAV
- Store in a fireproof container
- Keep them dry
- Keep them clean (the connectors on your batteries, chargers, and aircraft all need to remain clean and free of debris and dust)
- Don’t store in extreme temperatures or in high humidity
- Don’t store loose batteries together
- If you don’t plan to use a drone for several days, discharge its battery to 40%-65% of its capacity (depending on manufacturer recommendations) to prevent battery degradation
As mentioned above, batteries should have a chance to cool down after use before they can be charged. Additionally, draining them completely before charging is not necessary but, for some reason, it’s often recommended. The fact is that LiPo batteries shouldn’t drain below 3.0 V per cell to avoid damage.
Don’t charge your batteries right after a flight or before storing. It’s better to wait until the day of, or the day before, the flight. If you have multiple batteries, cycle through them instead of using just one. Keep a tab on them all to balance the pressure you put on them.
Never forget your battery or leave it unattended when charging. Charging UAV batteries is not akin to plugging in your phone and going to sleep. Again, LiPo batteries can be volatile and overcharging can be very dangerous.
UAV batteries are more complex and more dangerous than everyday use batteries. They should be treated responsibly and with caution. It’s also important to inspect them regularly for any signs of damage or puffing. To stay safe, it may even be a good idea to invest in a battery health analyzer. It can provide you with information on the state of each cell in the battery even when faults are not physically visible.
And remember to dispose of damaged or old batteries safely at your local hazardous waste center.