How we recommend
We recommend gear by category and use, not by brand, and do not quote prices. We may earn a commission on purchases at no cost to you.
Fly within the rules
This page explains what aviation authorities, model-aircraft associations, racing bodies and researchers publish. It is not legal advice and not a substitute for your aviation authority's own rules, a club safety officer or proper training.
A battery fire is an emergency
A smoking or burning lithium battery needs the emergency services, and a burn needs medical care. This guide gives no charging, storage, disposal or firefighting steps, and no battery, charger, bag or case is presented here as preventing a fire.
Cell count: the class decides
No standard was found that defines the hobby's "S" cell-count label or its "C" rating, so this guide uses cell counts only as racing rules write them and gives no C ratings. Each body's rule applies only to its own races; they are never combined here.
| Body and class | Battery rule as published |
|---|---|
| FAI F9U (Volume F9, 2025 edition, C.1.2, effective 1 May 2025) | Packs up to 6S; no cell above 4.25 V when fully charged (17 V for 4S, 25.5 V for 6S); pack voltage measured before each race. Under C.4 the organiser may check each registered model's battery voltage |
| MultiGP Open | At most 4.35 V per cell |
| MultiGP Whoop | 1S, any capacity, at most 4.35 V |
| MultiGP Micro | Up to 3S at 4.35 V per cell |
| MultiGP Freedom Spec | Up to 6S |
| MultiGP Pro Spec | 6S of 2200 mAh or less |
| AMA FPV club racing recommendations (16 June 2016) | 4S LiPo or LiFe packs; whether this 2016 document has been superseded is unconfirmed |
The FAI's 2025 change log lists the per-cell limit among the changes effective 1 January 2020 and describes it as a safety measure. A 2026 edition of Volume F9 exists and was not read; its effective date is reported as 1 January 2026 and as 1 June 2026. MultiGP's figures are from its class page, read 30 October 2026; its Rule Book was not read. The F9U model checker compares a pack's cell count and voltage with the FAI's 2025 limits.
Travelling with packs
IATA's passenger guidance of 31 March 2026, based on the 2025-2026 ICAO Technical Instructions and the 67th edition of the IATA Dangerous Goods Regulations, sets limits for lithium-ion batteries by Watt-hour rating. In summary: spare batteries are carry-on only and must be individually protected against short circuit; up to 100 Wh needs no operator approval; over 100 Wh up to 160 Wh needs operator approval, with at most two spares per device; over 160 Wh goes only as cargo. IATA names drones among items with batteries over 100 Wh for which passengers should check with the airline. IATA says its guidance should not be relied on as a source of regulatory compliance. The guidance, re-read for this site on 30 October 2026, defines lithium-ion and lithium metal batteries and does not mention lithium polymer by name, so this site does not say which of IATA's categories a particular pack falls into. IATA's operator guidance on power banks says the 68th edition, in force from 1 January 2027, will carry ICAO's March 2026 changes.
US federal limits could not be confirmed because FAA and PHMSA pages refused access. The full table, the UK CAA's position and the unconfirmed US position are on flying with batteries.
What the fire hazard rests on
No fire-service or NFPA page specific to drone LiPo batteries was found for this site. The hazard description rests on three kinds of record:
- A UL fact sheet (2023, hosted by the New Jersey Division of Fire Safety) on lithium-ion batteries, which says they can overheat, catch fire and cause explosions, most commonly when damaged, subjected to electro-chemical abuse (overcharging or completely draining are its examples), exposed to high or low temperatures, or affected by an internal short circuit. It advises choosing products listed or certified by a nationally recognised testing laboratory, and says many products sold online do not meet those standards.
- US Consumer Product Safety Commission recalls: in recall 08-364 (19 August 2008) the CPSC stated that lithium-polymer batteries for a radio-controlled helicopter could overheat and catch fire while charging. In recall 25-066 (12 December 2024) it said a battery charger could ignite or cause a connected battery to ignite.
- IATA's air transport guidance, summarised above.
More on battery fire risk and recalls.
Batteries and the FCC Covered List
In the United States, the FCC's fact sheet of 7 January 2026 names batteries and battery management systems among drone critical components on its Covered List, and also says generic batteries and similar parts that never needed FCC authorisation do not newly need it. No later FCC statement was read, so the list's state on 30 October 2026 is unconfirmed. See the FCC Covered List.
Our picks by category
LiPo batteries
Lithium-polymer flight packs. The class sets the cell count: up to 6S at 4.25 V a cell for FAI F9U (2025 edition), one cell for MultiGP's Whoop class, up to 3S for its Micro class. For air travel, IATA's lithium-ion limits turn on the Watt-hour rating marked on the battery (IATA does not name lithium polymer), and IATA says an operator may refuse a battery whose rating staff cannot verify.
Best for: Pilots matching packs to their class's cell and voltage rule
Battery chargers
Chargers sold for lithium-polymer packs. This guide names the category only and gives no charging steps. UL's fact sheet advises products listed or certified by a nationally recognised testing laboratory, and the CPSC has recalled at least one charger for a fire hazard; check recalls before buying.
Best for: Pilots who need a charger for lithium-polymer packs
Sources
- FAI Sporting Code Section 4, Volume F9 Drone Sports, 2025 edition (effective 1 May 2025)
- FAI, SC4 volume CIAM F9 Drone sports 2026 (listed; host did not resolve, not read)
- MultiGP, Race Class Specifications (read 30 October 2026)
- MultiGP, Rule Book page
- AMA, FPV Multi-Rotor Club Sport Racing Recommendations (16 June 2016)
- IATA, Passengers Travelling with Lithium Batteries (31 March 2026)
- IATA, Guidance to operators: power banks (2026)
- UL, lithium-ion battery fact sheet (2023), hosted by the New Jersey Division of Fire Safety
- CPSC, recall 08-364, batteries used in radio-controlled helicopters (19 August 2008)
- CPSC, recall 25-066, battery chargers (12 December 2024)
- FCC Fact Sheet, Covered List updates and FAQs (7 January 2026)