Redundant BMS architecture

Example

Use in Lemonergy

Make series/parallel architecture explicit.

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

Connected concepts

Related concepts from the knowledge graph. Connections show context, not cause and effect. Hover or focus a linked term for its definition.

BMS architecture

How a BMS’s electronics are divided across the pack. A centralised BMS wires every cell to one board, suiting small packs; a modular or master–slave design puts a monitoring board on each module reporting to one controller; a distributed design puts electronics on each cell. Stationary systems add tiers: module, rack and system-level BMS.

Current sensor

The device that measures pack current for coulomb counting and protection: a precision shunt resistor read by an amplifier, or a Hall-effect sensor around the cable. Offset error in this sensor is what makes SOC drift between OCV corrections.

Diagnostic coverage

The fraction of a component’s failure rate that a safety mechanism detects or controls. ISO 26262 treats coverage from about 60% as low, from 90% as medium and from 99% as high; comparing two independent measurements of the same cell voltage typically earns high coverage, while a simple plausibility check earns much less.

Functional safety

The discipline, standardised for vehicles in ISO 26262, of making sure electronic failures do not cause harm. Battery functions such as overvoltage protection are classified by risk into ASIL levels A to D, which set how redundant and verified their hardware and software must be.

Hardware safety metrics

The ISO 26262 numbers showing that random hardware failures are under control. The single-point and latent fault metrics are the shares of failures that safety mechanisms cover — at least 99% and 90% for ASIL D — and PMHF is the residual rate of violating a safety goal, below 10⁻⁸ per hour (10 FIT) for ASIL D.

Lockstep core

Two identical processor cores running the same program slightly offset in time, with hardware comparing their outputs continuously. Any mismatch, from a radiation-flipped bit or a silicon fault, triggers a reset or safe state, giving the high diagnostic coverage a BMS controller needs for ASIL C or D.

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.