Battery fire risk, as safety bodies and recall notices describe it.

What this page rests on

The research behind this site looked for a fire service or a fire-protection standards body publishing guidance specific to lithium-polymer batteries in drones or hobby models, and found none. The hazard described here therefore rests on three kinds of source, each named where it is used:

• A general lithium-ion fact sheet from Underwriters Laboratories (UL), dated 2023 and hosted by the New Jersey Division of Fire Safety. It covers lithium-ion batteries in general, not drone batteries in particular.
• Recall notices from the US Consumer Product Safety Commission (CPSC) for hobby batteries and chargers. None of the recalls found concerns an FPV racing battery.
• Aviation bodies: an FAA warning reported by the Academy of Model Aeronautics' magazine, and IATA guidance dated 31 March 2026.

What the UL fact sheet says

The UL fact sheet names four conditions under which lithium-ion batteries most commonly overheat, catch fire or explode: when they are damaged; when they suffer what it calls electro-chemical abuse, giving overcharging and draining completely as examples; when they are exposed to high or low temperatures; and when an internal short circuit occurs.

It calls thermal runaway the primary driver of lithium-ion battery risk. In its description, a cell begins to heat itself, reaching more than 1,000 degrees Fahrenheit, and breaks down into smoke and flammable and toxic gases. The heat can then spread to neighbouring cells in the same battery. The fact sheet says thermal runaway often starts a fire straight away, and that where ignition is delayed, the flammable gases can build up and cause an explosion.

Two further points in the fact sheet bear on how quickly things happen. It says a person may have less than a minute to escape a battery fire from the first sign of trouble. And it lists warning signs: swelling or punctures, unusual hissing or popping, excessive heat or a strange smell, and white or grey wispy smoke, which it treats as a sign of immediate danger of thermal runaway.

The fact sheet also recommends products listed or certified by a nationally recognised testing laboratory, and says many products sold online do not meet those safety standards.

Two temperature figures

The figures in circulation do not agree. The UL fact sheet gives more than 1,000 degrees Fahrenheit for thermal runaway. A statement attributed to a New Zealand fire service, seen only as text quoted on a mailing list, gave more than 1,000 degrees Celsius for lithium-polymer fires and described a fireball about 1.8 m across. The original of that second statement was not found, so it is unconfirmed.

Recall notices

The CPSC's notices describe what went wrong with specific products. They are records of particular faults, not measures of how often hobby batteries fail. Details of each recall are on recalls.

Three caveats go with the table. The CPSC's own page for the HTRC C240 charger does not mention drones; a university news item, seen only as a search summary, says the chargers were sold for lithium-polymer batteries such as those in drones. On the Pixy, the CPSC listing names the battery, while some news outlets reported a recall of the whole drone; press reports also gave four reports of overheating and bulging, one minor battery fire and one minor injury, figures not checked against the CPSC notice. The Pixy is a consumer camera drone, not FPV racing equipment.

Gaps in the US data

The CPSC's main published dataset on lithium-ion fires, its 2017 to 2023 report on micromobility products such as e-bikes, e-scooters and hoverboards, does not cover drones, and its figures say nothing about drone batteries. A search summary of a CPSC regulatory analysis, not confirmed on the document itself, says the fire incident data CPSC staff use has no product category for lithium-ion batteries, which limits how such fires can be counted.

Lithium batteries on aircraft

Aviation bodies treat lithium batteries as a fire risk in flight. The AMA's magazine, Model Aviation, reported that on 9 February 2016 the FAA warned lithium-polymer and other lithium batteries may be unsafe as cargo on passenger airliners, saying cargo fire suppression systems cannot effectively control a lithium battery fire and that there is a potential risk of catastrophic loss of the aircraft.

According to search summaries, the FAA keeps a chart of smoke, fire and extreme-heat events involving lithium batteries on US aircraft that it is aware of, and says the chart is not a complete listing; the FAA's site could not be opened for this research. Those summaries and a trade write-up report a 2025 total of 93 incidents, 31 of them involving battery packs. None of this is confirmed on the FAA's own pages.

IATA's guidance to airlines dated 31 March 2026 says power banks are an increasing concern for thermal runaway and fire on aircraft. It points to low barriers to manufacturing and to products that do not conform to the UN 38.3 test standard, and notes that UN 38.3 is a transport test, not a consumer product safety standard. The same document reports an ICAO addendum issued on 27 March 2026, effective that day, that separates power banks from spare batteries, limits passengers and crew to two power banks for personal use and bars recharging power banks in flight. IATA says the guidance applies with the 67th edition of its Dangerous Goods Regulations, is not effective beyond 31 December 2026, and that the 68th edition, in force from 1 January 2027, will contain the changes. The carriage limits for drone batteries, by authority, are on flying with batteries.

Batteries in the racing rules

The FAI's racing rules address batteries as rules, not as fire protection. In the FAI Sporting Code, Volume F9, 2025 edition (effective 1 May 2025), rule C.1.2 limits F9U racing packs to 6S with no cell above 4.25 V when fully charged, voltage is measured before each race, and the edition's change log lists the cell-voltage limit among the changes effective 1 January 2020 and describes it as a safety measure. Rule C.8.2 provides a full race restart after a critical safety incident, naming a fire as an example, and Annex C.1 requires the organiser to prepare basic fire and first-aid procedures for the area inside the safety line. A 2026 edition of the volume exists but could not be read; its effective date is reported as both 1 January and 1 June 2026, and its wording may differ. More on race safety rules.