How many kWh is a Toyota Mirai battery?
Approximately 1.6 kWh.
The Toyota Mirai is a hydrogen fuel-cell vehicle that carries a small on-board lithium‑ion battery. It is not a plug‑in vehicle, so the battery is not sized to provide long driving ranges on electricity alone; instead, it buffers power for the fuel-cell stack, stores energy recovered from braking, and smooths transitions during power demand.
What the battery does in a fuel-cell vehicle
In modern hydrogen cars, the battery is intentionally small. It serves to boost efficiency and responsiveness without the large capacity of an electric vehicle's pack. Toyota's Mirai uses a compact pack to support the fuel cell and to provide energy for start-stop and rapid acceleration until the fuel cell can meet the demand.
Key facts about the Mirai battery:
- Capacity: around 1.6 kWh (roughly 1.4–1.9 kWh depending on year and market)
- Type: lithium-ion battery pack
- Role: energy buffering, regenerative braking energy storage, and quick-peaking support for the fuel-cell stack
- Not a plug-in: the car is designed as a fuel-cell vehicle; the battery is not intended for long-range electric driving
In practice, the battery helps the system respond smoothly at low speeds, buffers transitions in power demand, and stores regenerative energy. The primary energy source for propulsion remains the hydrogen fuel cell and on-board hydrogen supply.
Generation differences and official specs
Toyota does not publish an official kilowatt-hour rating for the Mirai battery in the basic specification sheets. Independent reviews and teardown analyses for the second-generation Mirai commonly cite a pack around 1.6 kWh, with minor variations across model years and markets. This small capacity reflects its role as an energy-management buffer rather than a large energy-storage system like in plug-in hybrids or battery-electric vehicles.
Summary
The Toyota Mirai uses a compact lithium-ion battery of about 1.6 kWh. It is not designed as a long-range energy store or a plug-in system; instead, it supports the fuel-cell stack, absorbs regenerative energy, and helps deliver quick power when needed. As with many hydrogen fuel-cell vehicles, the battery size is modest by EV standards, reflecting its specific role in the propulsion system.
