Will Drone Battery Explode if They are Bulging

Expanded drone batteries can explode or catch fire because expansion indicates an internal malfunction and a buildup of flammable gases. While not all expanded batteries will explode immediately, they are extremely unstable and should be considered hazardous. Always stop using batteries immediately, store them in a safe, non-flammable container, and dispose of them properly at a designated hazardous waste disposal facility.

Why do Drone Batteries Bulge?

A bulging battery is not a coincidence; it is often a sign of an internal problem. Here are the main causes:

• Overcharging: When Li-Polymer batteries are charged above safe limits (e.g., a faulty charger, or a user accidentally leaving the battery on charge for an extended period of time), too much heat can build up, which in turn generates gas, causing the battery to bulge.
  

• Over-discharge: When a battery is discharged below a safe voltage range (typically below 3.0V per cell), its chemistry becomes unstable, which can cause internal damage and lead to bulging.
  

• Physical Damage: Dropping the drone, a sharp impact, or even a small crack in the battery casing can damage the internal structure and lead to gas buildup.
  

• Manufacturing defects: Poor quality control during production can cause gas pockets to form inside the battery, which can grow over time and cause the battery to bulge.
  

• Aging and Wear and Tear: Like all rechargeable batteries, drone batteries have a limited lifespan. After many charge/discharge cycles, the battery's internal chemistry degrades, making it more susceptible to problems such as bulging.
  

Can a Bulging Drone Battery Explode?

Simply put: a bulging battery won't necessarily explode, but it has become extremely unstable.

The reason for the bulge: the battery's flexible casing expands to accommodate flammable gases from internal malfunctions, which is a protective mechanism of sorts, but that protection is limited.

High Risk Warning Signs (when the risk of explosion or fire skyrockets):

• The battery continues to bulge.
  

• Smell a strange sweet or chemical odor.
  

• Battery is hot to the touch.
  

• See smoke coming from the battery.
  

While “explosions” are rare, lithium polymer battery fires (called “deflagrations”) are very intense and can quickly ignite surrounding objects. So, a bulging battery is definitely a serious fire hazard.

Warning Signs of a Dangerous Drone Battery

• Discontinue use immediately if you notice any of the following with your battery:
  

• Visible bulging or swelling (the most visual danger sign).
  

• Gets hot while charging or discharging (beyond normal operating temperatures).
  

• Fluid leakage (indicating severe internal damage).
  

• Cracks or punctures in the case (destroying the integrity of the battery).
  

• Sudden shortening of range or deterioration in performance (may be a precursor to bulging packs).
  

What Should I do if I Encounter a Bulging Drone Battery

To act quickly to minimize the risk, the steps are as follows:

Start with Safety Precautions

Wear gloves and a mask: prevent leaking liquids from touching your skin and avoid inhaling toxic gases.

Keep away from flammable materials: Keep the battery away from any combustible materials such as fuel, paper, etc.

Operate in a well-ventilated area: Open windows to allow harmful gases to escape.

Remove the Battery Immediately

Carefully remove the bulging battery from the drone (avoid squeezing or puncturing the battery). Place the battery in a non-combustible container (such as a metal box or fireproof bag) to prevent the spread of fire in the event of a fire.

Do not Reuse UAV Drone Batteries

A bulging battery cannot be “repaired” and reuse may cause a fire, explosion, and also damage the drone.

Dispose of Batteries Correctly

Do not throw bulging batteries in the trash, as lithium polymer batteries contain toxic substances. You can find a designated battery recycling center (consult your local waste management department or electronics store for information on recycling points).

Check other Drone Batteries

If one battery is bulging, check the other batteries. This is because manufacturing defects may affect more than one battery.

What to Do if  Your Drone Battery Explodes or Catches Fire

• Evacuate immediately: move quickly away from the battery and avoid contact with smoke and flames.
  

• Notify others: Alert anyone nearby to leave the area.
  

• Call an emergency number: Firefighters are professionally trained to handle lithium polymer battery fires.
  

• Do not try to extinguish the fire: Water may spread the fire, let professionals use the appropriate extinguishing equipment.
  

• Ventilate: After the fire is extinguished, open windows to remove toxic gases.
  

How to Prevent Drone Battery Bulging

Avoid battery bulging at the source by doing the following:

Use a High-quality Li-Polymer-compatible Charger

Prevent overcharging by choosing a charger with a balancing function (which ensures even charging of each cell, helping to improve battery performance and avoid premature signs of aging) and an automatic power-off function. For example, the compact and portable IMARS III charger from GROB ACE also has the necessary safety features.

Avoid Overcharging and Overdischarging: 

Do not leave it unattended while charging and stop using it when the battery reaches the low voltage cut-off point (check the drone's manual for specific parameters).

Store and use at room temperature: extreme heat (e.g. direct sunlight) or low temperatures can damage the battery's chemistry. After use or charging, allow the battery to cool to room temperature before storing.

Store and use with care: avoid dropping, bumping or puncturing the battery, hold it gently and protect the battery case.

Conclusion

A bulging drone battery is dangerous, but not always explosive, though immediate countermeasures must be taken. OKCELL has been focusing on R&D and production of UAV batteries for 20 years, and supports customized UAV battery solutions according to customer needs. Whether it is a quadcopter, hexacopter or octocopter drone, our battery products are well adapted to cover most of the mainstream models in the market, and are widely recognized and praised by users. If you have related needs, welcome to contact us online or call us.