Battery Management Service

group Battery Management Service

Monitors and controls the CubeSat battery pack.

The BMS is responsible for:

  • pack voltage/current monitoring

  • temperature and health estimation

  • charge state determination

  • enabling/disabling charging/balancing circuits

  • protection and failsafe behavior

  • telemetry collection for upstream consumption

  • error state management by notifying redundancy manager

group Structures

Structures used by the Battery Management Service.

struct battery_status_t
#include <battery_management.h>

Snapshot of system battery state.

This structure is returned by battery_get_status and is used internally by the BMS to make decisions.

Public Members

float voltage

Current pack voltage in volts

float current

Pack current in amps (+ = charging, - = discharging)

float temperature

Average pack temperature in C

float soc

State of charge (0-100%)

float soh

State of health estimate (0-100%)

bool charging

True if charging is currently active

bool balancing

True if balancing circuits are enabled

struct battery_management_t
#include <battery_management.h>

The battery management service.

Public Members

battery_status_t battery_status

The battery status

bool intiialized

True if the BMS is initialized

group Public API

External interface for interacting with the Battery Management Service.

Functions

void battery_init(battery_management_t *manager)

Initialize the Battery Management Service.

This must be called once at startup before any other BMS functions. Initializes internal state, and performs a startup self-check.

Note

This function is idempotent.

Parameters:

manager – [out] The battery manager

void battery_update(battery_management_t *manager)

Perform a periodic update of battery status.

This should be called once each main loop tick. Reads sensors, updates SoC/SoH estimates, and runs charge/protection algorithms.

Parameters:

manager – [in] The battery manager

bool battery_self_check_ok(battery_management_t *manager)

Returns whether the battery system passed its self-check.

Parameters:

manager – [out] The battery manager

Return values:

  • true – Battery is healthy and operational.

  • false – Battery failed diagnostics; EPS may require safe mode.

bool battery_needs_charge(void)

Determine if the battery requires charging.

Uses SoC, voltage thresholds, and EPS policy rules.

Return values:

  • true – Battery is below charging threshold.

  • false – Sufficient charge level or charging not allowed.

bool battery_full(void)

Determine whether the battery is considered full.

Typically derived from voltage or SoC limit.

Return values:

  • true – Battery is full or very near full.

  • false – Battery still has capacity to charge.

void battery_charge_control(void)

Apply charge-control policy.

Enables or disables charging circuits based on SoC, temperature, EPS power budget, and safety limits.

void battery_protect_mode(void)

Enter battery protection mode.

Used during overvoltage, deep discharge, or other critical conditions. May disable EPS rails or charging.

battery_status_t battery_get_status(void)

Get the full status snapshot of the battery system.

Returns:

battery_status_t struct with all telemetry fields populated.

float battery_get_voltage(void)

Get battery pack voltage.

Returns:

Measured voltage in volts.

float battery_get_current(void)

Get battery pack current.

Positive = charging, negative = discharging.

Returns:

Current in amps.