# MHEV (Mild Hybrid Electric Vehicle)

> Light hybrid system with a secondary 48 V network that assists the engine on acceleration and recovers energy on braking.

**Categoría**: Vehicle features
**URL canónica**: https://baterias.com/gb/battery-glossary/mhev
**Idioma**: en-GB

## Definition

MHEV (Mild Hybrid Electric Vehicle) is a "light" hybrid: the combustion engine is the only one that moves the car, but a **48 V (non-traction) electrical system** assists during starts, transitions and acceleration, and recovers energy during braking. It reduces fuel consumption by 8-15% in mixed driving compared with the same non-hybridised engine. It uses a **compact 8-15 Ah lithium battery at 48 V** (sealed module, not user-replaceable) and keeps the conventional 12 V battery to feed accessories. Brands with widespread 48 V MHEV: Audi (broad range since the A8 D5 in 2017), BMW (progressive 48 V rollout between 2019 and 2021), Mercedes (EQ Boost), Land Rover, and much of the VAG group. Mazda and some Asian brands use mild-hybrid systems at **24 V** rather than 48 V (Mazda "M Hybrid"). It is NOT the same as a **full hybrid (HEV)**, which can move the car under electric power. The 12 V battery the user replaces is still a conventional AGM or EFB — the mild-hybrid system is separate.

## See also

- [HEV (Full Hybrid)](https://baterias.com/gb/battery-glossary/hev)
- [PHEV (Plug-in Hybrid)](https://baterias.com/gb/battery-glossary/phev)
- [Start-Stop](https://baterias.com/gb/battery-glossary/start-stop)
- [Regenerative braking](https://baterias.com/gb/battery-glossary/regenerative-braking)

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