In the world of DJI drones, there are so many important and complex parts that work together to create a functioning whole. I’ve had a couple of bulging batteries in my time as a drone pilot and it can be tempting to fly with a puffy battery.
DJI battery bulge is caused by overcharging, mishandling, and aggressive use of the drone. It is often irreversible and you should replace the battery as soon as possible to avoid the risk of an explosion or it popping out of your drone mid-flight.
Drone batteries can bulge for a variety of reasons, and it’s important to know what to look for and how to deal with this issue if it arises.
The bulging of a DJI battery is relatively common. There are many different reasons that a battery can bulge including high temperatures and end-of-life decomposition. It is important that you monitor your battery health as often as possible and stop using your DJI battery as soon as you notice significant swelling.
Examples of battery bulging
Here are a few examples of batteries that have been reported to bulge from various forums and online sources.
Should you notice any of these symptoms you should consider changing your battery immediately.
Knowing more about why batteries bulge and how you can ensure that your drone stays safe by minimising the chance it happens to you is important.
Here is everything you need to know about keeping your DJI battery from bloating.
Why does a DJI battery bloat?
Gas generation in drone batteries involves many complicated reactions and is primarily caused by the decomposition of the battery electrolyte. The chemical decomposition of the electrolyte is catalysed by the battery materials and can be sped up by improper storage, use and maintenance of the battery.
A DJI battery bloat happens when the battery is charged incorrectly, has been damaged, or has been compromised in some other way.
Common battery misuse that can result in DJI battery bloat include:
- aggressive flying – increases the temperature of the drone battery
- flying in high winds – causes the battery to work hard and overheat
- allowing your battery to deplete fully – a healthy battery should never be allowed to completely discharge.
- Flying on a hot day – causes the battery to overheat
- storing when full – intelligent batteries will slowly deplete their charge to avoid this issue.
- Mechanical damage – dropping and shocking the battery can cause bloating.
A bloating DJI battery is a sign that the battery is failing, and you should dispose of the battery immediately.
While most modern devices are designed to prevent this from happening, it’s still important to be careful when charging and using your lithium polymer battery.
The symptom of bloating of a DJI battery is caused by gases being generated via electrolyte decomposition.
Electrolyte decomposition – DJI battery bloat
The electrolyte of a battery is the material that allows for charges to be transferred between the metallic components of the battery. It is often a liquid or polymer that is capable of carrying charge.
The battery of a drone swells because the electrolyte is decomposing.
As the electrolyte decomposes into several gaseous compounds including oxygen, carbon monoxide, ether, and carbon dioxide.
Because drone batteries are sealed in an airtight wrap, the gases will blow up the battery like a balloon.
Although the airtight plastic wrapping is very flexible and the battery can swell up to a considerable size, you must move this battery away from any ignition sources that would further stress the battery.
How to tell if your drone battery is bloating
If you are concerned that your drone battery is bulging there a number of really subtle changes that you can look for to determine whether or not you should be concerned.
Here, we will go through all the simple checks that you can make to see if your drone battery is bulging.
One of the most subtle but obvious symptoms of a DJI battery bulge is rounded surfaces.
Typically, a DJI battery will have a number of flat surfaces. I recommend keeping an eye on how the surface of the battery changes and take note of any particularly rounded surfaces.
Place the DJI battery on a flat surface and spin it around. A flat battery will not spin easily and will stop immediately. Unfortunately, if your battery continues to spin on a flat surface you have likely got the beginnings of a bulge.
Once the battery starts showing this bulging, you can wait to see if it settles down by allowing the battery to cool down and sit undisturbed for at least 24 hours.
Sometimes the slight bulging is due to heat and will return to normal once cooled.
Plastic case discoloration
The degradation of the electrolyte material can cause discolouration in the battery casing.
Keep an eye out for any discolouration on the battery edges and corners. This could be one of the first signs that the drone battery is getting too warm which could result in a battery bulge.
Plastic case seams opening
One of the later symptoms of a DJI battery bloat for bulge is the plastic seam of the intelligent battery opening.
As the inside battery components start to swell up the external casing can no longer hold its contents.
It may only start as a very small gap in the case, but if left un-treated it will continue to expand and potentially pop all of the seams. You replace the battery as soon as possible if you notice the plastic case coming apart.
Unable to fit in drone
One of the last and final symptoms you will have of a drone battery bloating is when it can no longer fit in your drone.
DJI batteries are manufactured with very small tolerances so that all of the components fit into the small drone body.
The drone battery has been designed to fit firmly and snugly into the drone frame. Even a small 2 mm bulge will cause the battery to no longer fit in the drone.
Should you notice that your drone battery is no longer able to fit into the drone, cease use immediately and allow to cool and sit for 24 hours before deciding whether or not the swelling has made the battery unusable.
How much bloating is too much?
A small amount of bloating sometimes occurs on a DJI drone battery due to use and heat.
As the drone is charged or discharged there is a significant amount of heat exchange due to the fast exchange of electrons within the battery and drone.
It could be that the drone battery can be saved as long as you treat it with care.
Once there is a significant amount of bloating and you can no longer fit the battery into the drone or you notice that it has changed in size quickly, it is time to change the drone battery as soon as possible.
A rule of thumb for whether you should change your battery is – if you are asking this question, yes, it is time to dispose of the DJI drone battery that is bulging and buy a new one.
Can a bulging drone battery be fixed?
Small amounts of bulging have been able to be reversed by allowing the drone battery to cool down after use.
Pay particular attention to the rate of change of the volume size to determine whether it is a serious issue that needs to be fixed.
No way to recover after serious bloating
Once a drone battery has bulged significantly, there is no way to recover or refresh the drone battery and you should dispose of the battery and buy a new one as soon as possible.
Are bulging batteries safe?
From experience, it seems that a small amount of swelling seems normal. However, significantly bulging batteries are not safe.
The build-up of gases in a confined area can cause explosive discharge should the casing become compromised.
Also, these batteries contain lithium and oxygen that can explosively react with the slightest of impacts or if given enough time.
Please note: It is always best to err on the side of safety when it comes to batteries. If you are not sure if a battery is safe, don’t take the risk – take it to a professional to have it checked out.
You can make sure that your batteries are extra safe by storing them in a fireproof case.
Store batteries in a fireproof case
If you want to know more about the best drone battery protectors and how to store your drone battery safely, check out my other article – click here – where I go through everything you need to know about storing your batteries.
Ultimately batteries need protection from corrosion, damages sustained during storage and transport and from lots of heat.
In a 2000 study, scientists created a mathematical model which looked at the heat transfer and thermal management of lithium polymer batteries. They found that under some conditions batteries can reach 106° C. So making sure that your drone batteries are protected from heat after flying (where they are likely to get the hottest) is an important part of protecting your drone battery.
There is a huge range of fireproof and explosion-proof protective bags for each type of drone that you can buy. If you regularly carry a spare battery for your drone flight I recommend that you purchase a protective bag to protect against heat and damage.
- Li-Po Battery Safe Bag Fireproof Storage Bag for DJI Mavic 2 Zoom / Pro Drone. 3-Pack of Small Size.
- Charge with confidence knowing your home is safe from a lipo fire. Fire prevention, Radiation protection, Explosion-proof.
- Material: Fireproof nylon, weight: 42g (Small) Color: black
- Great for traveling, charging, storage, keep your stuff away from a fire disaster.
Will DJI replace swollen batteries?
Sometimes, DJI will replace swollen batteries if there has been a known manufacturing fault reported. For example, the DJI Mavic 2 had an issue with batches of batteries which would become swollen.
There is more information in the YouTube video, below.
If you are unsure of whether or not you are able to get replacement batteries from DJI I would recommend reaching out to their customer support to ask for more information.
How to stop your drone battery from swelling
If you want to look after your drone batteries properly then you should follow these simple rules. Treat them with care and respect and there is no reason you can’t get them to last for many years. If you do it properly, they will last for the entire 500 or more charge cycles.
Keep them clean and dry
Store your batteries in a clean and dry area. Avoid contact with moisture and excess dust. If the battery comes into contact with moisture it can rust and corrode the contacts. If you want, you can clean the metals contacts with isopropyl alcohol (IPA) if you need to clean off some dirt that has accumulated,
Let your batteries cool off before charging
If you are like me – you will be eager to get back in the air as soon as you land your drone. However, charging up your drone battery as soon as you land is not a great idea! During flying the batteries discharge at a fast rate and all this movement of electrons can cause a little bit of heating. The battery shouldn’t get really hot, but it’ll heat up a little bit.
Wait 20 minutes before charging again – this will protect the battery from over heating as charging the batteries can also cause the battery to heat up.
Store at 50% charge
Never leave your drone batteries fully charged if storing for long periods of time – like over a month. It is best to leave your batteries at 3.9 volts per cell if you are not planning on using them within a week. 100% charges LiPo batteries are much more unstable than when at 50 % – increasing the likelihood of a short.
Some of the smart batteries will also discharge themselves so that they reach about 3.9 V per cell. Here are some basic rules of thumb if you want to store your drone batteries for various lengths of time:
- Short-term Storage – Batteries should be discharged to between 60 and 80% if you’re not using them for between one and ten days.
- Long-term Storage – If storing for more than ten days, store the battery between 40 and 60%. Batteries should not be left for over three months without being charged as the battery life will be reduced.
Cycle the LiPo batteries for 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.
Keep in a cool spot
You should make sure that your lithium polymer batteries are kept in a spot that is no more than 40° C. Leaving the batteries in the back of a car while on a shoot for example is a very bad idea. Cars can easily get very hot in the sun and incredibly cold during the winter months. If you can you should carry your batteries with you at all times so that they do not get too cold or too hot.
Use the correct chargers
Never be tempted to use anything other than official DJI charges and charging hubs.
DJI batteries are getting smarter with each drone release and will require very specific charging conditions.
Always use the official charges for your drone batteries to avoid overcharging and the battery swelling.
Do not over or undercharge
Charge or discharge the battery to 40% ~ 60% if NOT intended to be used for 10 days or more. This can greatly extend the battery’s overall life span. It takes approximately 6 days to discharge the battery to 60%.
It is normal that you may feel moderate heat emitting from the battery during the discharge process. You can set the discharging thresholds in the DJI Pilot app. It’s recommended to store the batteries in the Battery Station.
DO NOT store the battery for a long period of time with its power fully discharged. It may lead to irreversible damage.
Avoid extreme temperatures
Avoid extreme temperatures during use and storage of your drone battery. For example, never leave your DJI battery in a hot car or in direct sunlight in a bag.
I learned the hard way when I took my drone to the beach and left my drone battery in direct sunlight. The drone refused to turn on and I had to buy a replacement battery to ensure the safe flight of my drone.
Always store Intelligent Flight Batteries in a well-ventilated place that does not exceed the operating temperature of 50° C.
Take care when handling
Lastly, ensure that you treat your batteries with care.
Whether you are flying, storing, moving, or installing your battery, you must always handle them with care. They are designed for use but will only stand up to minor drops from small heights and prefer not to be handled roughly.
Handling your batteries carefully will ensure that they last much longer and you can avoid them swelling and becoming unusable.
Gas generation in drone batteries involves many complicated reactions and is primarily caused by the decomposition of the electrolyte. The chemical decomposition of the electrolyte is catalysed by the battery materials and can be sped up by improper storage, use and maintenance of the battery.
There is nothing that you can do to fix the drone battery and if you noticed the battery bulging you should dispose of the battery safely and replace it as soon as possible.
If the battery gets so large that the casing splits, the exposure to oxygen could cause an explosive reaction that can be very harmful to people and property.
In some instances, DJI have replaced bulging batteries and I recommend you reach out to their support services to see if they are able to provide you with a replacement.