# stuartpittaway/diyBMSv4

Version 4 of the diyBMS

Repository: https://github.com/stuartpittaway/diyBMSv4
Canonical: https://ross.abutalabs.com/products/diybmsv4
Language: HTML
License: NOASSERTION
License Family: other
Topics: battery, battery-management-system, bms, powerwall, 18650
Last push: 2025-07-25T19:30:41+00:00

## Health v2 (maintenance only)
Score: 47/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 33, release rhythm 35, longevity 100
- inputs: {"age_days": 2722, "days_push": 404, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1134, forks 239 (observed 2026-08-28T04:03:43.239963+00:00)

## What it is
Version 4 of a do-it-yourself battery management system (BMS) for lithium-ion battery packs and cells, including ESP32-based controller boards and cell monitoring modules. This repository contains the open-source hardware designs in KiCad format, with precompiled outputs for PCB fabrication.

## Use cases
- build a DIY battery management system for lithium-ion cells
- monitor and balance cells in a home powerwall
- design and order custom BMS PCBs from JLCPCB
- monitor 8 to 16S battery pack configurations
- log battery data to SD card with CANBUS and RS485 support

## When to choose
- you want an open-source, self-built BMS for a DIY powerwall or battery pack
- you need cell monitoring with optional passive balancing for lithium-ion cells
- you want hardware designs you can modify and fabricate yourself

## When to avoid
- you need a certified, off-the-shelf commercial BMS with safety guarantees
- you only want the firmware/software without building hardware
- you need active (not passive) balancing out of the box

## Facets
- artifact type: application
- maturity: active
- function: iot, embedded, monitoring
- domain: hardware, iot, energy, embedded-systems
- platform: embedded, iot
- tags: battery-management-system, bms, kicad, pcb-design, lithium-ion, powerwall, diy-hardware, cell-monitoring, esp32, attiny

## Member repositories
- stuartpittaway/diyBMSv4 (main) score 47

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:43.239963+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 2026-08-30T06:37:22.658859+00:00, confidence not recorded.
  - readme: https://github.com/stuartpittaway/diyBMSv4 (fetched 2026-08-28T04:03:43.239963+00:00, sha 09b5125a4f58)
- Data as of 2026-08-30T08:39:29.467469+00:00.