# zackelia/bclm

macOS command-line utility to limit max battery charge

Repository: https://github.com/zackelia/bclm
Canonical: https://ross.abutalabs.com/products/bclm
Language: Swift
License: MIT
License Family: permissive
Topics: macos, battery, battery-life, battery-health, smc
Last push: 2025-11-07T21:48:26+00:00

## Health v2 (maintenance only)
Score: 46/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 51, release rhythm 8, longevity 100
- inputs: {"age_days": 2264, "days_push": 299, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2187, forks 101 (observed 2026-08-28T04:06:23.812849+00:00)

## What it is
BCLM is a Swift command-line utility that reads and writes battery charge level max (BCLM/CHWA) values to the SMC on Intel and Apple silicon Macs. It helps prolong battery health by capping maximum charge, following the 40-80 rule for lithium-ion batteries.

## Use cases
- limit macbook max battery charge to 80%
- prolong mac battery health when plugged in all day
- read current battery charge limit from smc
- persist battery charge limit across reboots
- cap charging on apple silicon mac via command line

## When to choose
- you want a lightweight CLI to cap battery charge on a Mac
- you leave your Mac plugged in constantly and want to preserve battery health
- you're on macOS 14 or earlier with Intel or Apple silicon hardware

## When to avoid
- you're on macOS 15.0 or later, where the tool no longer works due to kernel entitlement enforcement
- you prefer a GUI battery management app
- you need scheduled or dynamic charging control rather than a static limit

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: developer-tools, cli
- domain: operating-systems, hardware, developer-tools
- platform: cli
- tags: battery-health, smc, apple-silicon, charge-limiting, macos

## Member repositories
- zackelia/bclm (main) score 46

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:23.812849+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:47:53.755119+00:00, confidence not recorded.
  - readme: https://github.com/zackelia/bclm (fetched 2026-08-28T04:06:23.812849+00:00, sha 3e9443241530)
- Data as of 2026-08-30T08:39:29.467469+00:00.