Battery knowledge · Modules, packs and battery management

Pressure-equalisation vent

A small vent in a sealed pack enclosure, closed by a microporous membrane, often expanded PTFE, that passes air but not water or dust. It equalises internal pressure as temperature and altitude change, protecting the seals without losing the IP rating; some designs add a burst element that opens wide to release gas in thermal runaway.

Also called
breather membrane, pack breather, pressure equalization vent, pressure compensation element, ePTFE vent

Example

Modules, packs and battery management: an example situation

Twelve 3.6 V, 5 Ah cells in 6s2p give 21.6 V, 10 Ah and 216 Wh nominally before other restrictions.

Read Pressure-equalisation vent alongside Enclosure in this context. The sealed case that carries the modules, protects them in a crash, keeps water out to an IP67 rating or better and vents gas in a thermal event. In many cars it is a structural part of the body.

Use in Lemonergy

Make series/parallel architecture explicit.

This is a reference concept. No executable Lemonergy block has been verified for this term.

References & further reading

Further reading on this topic

These sources provide broader context; they are not presented as citations for every statement in this entry.

  1. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 2. Modeling and identification

    Gregory L. Plett · Journal of Power Sources · 2004

    Topic background · Battery charge balance, open-circuit voltage, ohmic loss, polarization dynamics and model identification; parameters require cell-specific data.

  2. Getting Started with the BQ76925

    Texas Instruments · 2019

    Topic background · A concrete BMS analog front-end example: cell voltage, current, temperature measurement and MCU integration.