Nio Inc.‘s sub-brand Firefly has begun rolling out version 1.5.0 of its Aster OS in China, which includes software required to use the company’s upcoming fifth-generation battery-swap stations.
The update, announced on social media on Thursday, is the fifth major software release since Firefly deliveries began in April 2025.
With the latest version, Firefly also released the previously announced free over-the-air motor power upgrade from 105 kW to 120 kW.
The power boost itself was first revealed in early April alongside the refreshed version of the Firefly EV. It was scheduled for mid-May delivery to all existing owners.
No hardware changes are required. In Sport mode, the upgrade cuts the 0–100 km/h time to 7.9 seconds.
The upgrade makes the Firefly one of a small number of mass-market EVs to have received a free, software-only power increase after purchase — a feature Firefly has described as an industry first.
The refreshed model ships from the factory with the upgrade already included.
Battery Swap Integration
The most consequential feature in the 1.5.0 update is the addition of a battery swap station parking assist function — which lays the software groundwork for Firefly vehicles to use Nio‘s upcoming fifth-generation battery swap stations.
The system is designed to guide the vehicle into the swap bay semi-autonomously.
After placing a swap order at a fifth-generation station, the driver parks in a designated area in front of the station, taps a prompt on the infotainment screen to begin the swap process, and then initiates assisted parking.
Drivers can also choose to exit the process and contact a station attendant for manual assistance.
The inclusion of this feature is significant because Firefly has, until now, been the only Nio Inc. brand excluded from the company’s battery swap network.
Current fourth-generation stations support the Nio and Onvo brands but are incompatible with Firefly’s smaller 42.1 kWh battery pack.
The fifth-generation stations are being designed from the ground up to accommodate all three brands — from the compact Firefly to the recently unveiled ES9, Nio‘s largest SUV.
Nio‘s co-founder and President Lihong Qin has described the new generation as the company’s long-term infrastructure platform for battery swap.
Firefly confirmed in March that battery swap integration would begin rolling out in May, with pioneer fifth-generation stations opening to users for trial operations.
Nio plans to deploy five to 10 pioneer stations between May and June, with mass deployment now scheduled for the third quarter.
Nio’s 5th Gen Stations
The timeline for the deployment of fifth-generation stations has slipped repeatedly over the past months.
Nio first targeted a pilot run before Christmas 2025, then revised pioneer deployment to the first quarter of 2026 and mass rollout in the second one.
The company then pushed mass deployment to July or August.
The Aster 1.5.0 release notes warn that the fifth-generation station launch timing remains subject to official announcements.
Nio‘s swap network is the largest globally, with the company operating 3,846 battery swap stations in China as of Thursday.
The EV maker has provided more than 110 million battery swaps since 2018.
Founder and CEO William Li has guided to a year-end total of between 4,500 and 4,600 stations, with roughly 450 of the planned additions concentrated in the fourth quarter.
Additionally, Nio aims to deploy 3,000 battery swap stations through 2028.
Rollout
The Aster 1.5.0 update is being pushed in batches and may take several days to reach all vehicles. Vehicles must be running Aster 1.3.0 or later to be eligible.
The release continues the cadence Firefly has maintained since its operating system launched alongside the vehicle in April 2025.
Version 1.1.0 last August added dashcam functionality and blind-spot camera views, 1.2.0 in September introduced rear collision warning and optimized rain driving.
In early 2026, Firefly launched 1.3.0, which brought battery preheating and multi-language support.
Version 1.4.0 in April added mistaken-acceleration suppression, an emergency rescue service, and significant expansions to the Lumo voice assistant.
Firefly Deliveries
The update arrives as Firefly marks just over a year since deliveries began in China in late April 2025.
The sub-brand delivered 4,980 vehicles in April, an 18.6% sequential decline from the 6,119 units registered in March — the brand’s second-strongest month on record.
All three Nio Inc. brands posted sequential drops in April, with the group delivering 29,356 vehicles globally.
In the first four months of 2026, Firefly has handed over 16,563 vehicles.
The sub-brand crossed 50,000 cumulative deliveries on March 28, eleven months after handovers began.
The pace remains well below brand chief Daniel Jin’s stated target of 100,000 deliveries by year-end, with approximately 16.6% of that goal achieved through April.
Jin set an internal monthly target of 6,000 to 6,500 units from the second quarter onward — a threshold April fell short of.
In Europe, where the brand debuted in mid-August 2025 with deliveries in the Netherlands and Norway, sales remain modest.
Jin acknowledged in March that overseas sales in early 2026 had fallen “considerably” but maintained the brand’s target of launching in 20 to 30 countries this year.
