Feature request: Support SNMP as a meter source (PDUs / UPS / ATS)

[Vacxe]

Feature request: Support SNMP as a meter source (PDUs / UPS / ATS)

Summary

Add SNMP-based meter support to EVCC so that PDUs, UPSs, ATS devices, and smart rack power equipment can be used as power meters (W / A / V) for EV charging control.

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Motivation / Problem

Many homes, apartments, and small commercial sites already have rack-mounted power equipment that exposes accurate real-time load data via SNMP, but EVCC currently cannot use this data source.

Typical scenarios where this matters:

• Apartment buildings where EVSE is behind a shared rack / distribution board
• Home labs with centralised PDUs / UPSs
• Installations where no Modbus / CT clamp / smart meter is available or permitted
• Situations where adding new hardware meters is costly or not allowed

SNMP is widely supported, mature, and already deployed in these environments.

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Real-world devices that expose power via SNMP

Examples (all commonly found and SNMP-capable):

APC / Schneider Electric

• AP79xx / AP89xx – Metered & Switched Rack PDUs

  • Expose real power (Watts), current, voltage per outlet or phase

• APC Smart-UPS / Symmetra

  • Expose load watts, VA, input/output current

• APC AP7721 / Rack ATS

  • Exposes voltage, current, and (on some models) calculated watts

Eaton

• Eaton ePDU G3 / G4 (metered & switched)
• Eaton UPS (9PX, 5PX, etc.)

Vertiv / Geist

• Geist rPDU
• Vertiv Liebert UPS / PDU

All of the above already provide SNMP OIDs for power metrics and are used today in monitoring systems (Prometheus, LibreNMS, Zabbix, etc.).

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Why this feature is needed in EVCC

1. Zero additional hardware

   • SNMP devices already installed → no CT clamps, no Modbus meters

2. High accuracy

   • Enterprise PDUs & UPSs measure power directly at distribution level

3. Perfect fit for apartment & shared power

   • EV load can be limited based on actual upstream consumption

4. Common in home-lab + solar + EV setups

   • EVCC users often already run SNMP monitoring stacks

5. Works where Modbus is unavailable

   • Many devices only expose SNMP, not Modbus

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Proposed solution (high level)

Add a new meter type, for example:

meters:
  - name: rack_power
    type: snmp
    uri: udp://192.168.1.50:161
    version: v3            # or v2c
    auth:
      user: monitor
      securityLevel: noAuthNoPriv
    oids:
      power:   1.3.6.1.4.1.x.x.x   # watts
      current: 1.3.6.1.4.1.x.x.x   # amps (optional)
      voltage: 1.3.6.1.4.1.x.x.x   # volts (optional)
    scale:
      current: 0.1

Notes:

• Support SNMPv2c and SNMPv3
• Allow custom OIDs (vendor-specific)
• Support scaling factors
• If watts not available → optionally calculate from V × A × PF

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Minimal viable scope (MVP)

• SNMP GET / WALK
• One OID → power (W)
• Poll interval configurable
• Read-only (no SNMP SET required)

This alone would already unlock many deployments.

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Why this aligns with EVCC philosophy

• EVCC already integrates diverse, real-world energy sources
• SNMP is battle-tested, vendor-agnostic, and stable
• Keeps EVCC flexible in non-ideal electrical environments

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Willingness to help

I’m happy to:

• Provide real device OIDs (APC, Eaton)
• Test with live hardware
• Help validate configuration and documentation
• Can try to implement it when will have a time, but Im not a good Golang programmer :(

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Thanks for considering SNMP meter support — this would unlock EVCC for many existing installations without adding new hardware.

[Vacxe]

See: https://github.com/gosnmp/gosnmp

[andig]

this would unlock EVCC for many existing installations without adding new hardware.

It‘s not clear that should be the case.

EVCC users often already run SNMP monitoring stacks

I personally don‘t appreciate being dumped with ai-generated garbage. It’s painful having to read through this bloated mess of false claims. Why should rack consumption be a relevant measurement source for evcc?

[Vacxe]

@andig apologies for the AI generation

I solved all my requirements by adding SNMP as a Sensor to Home Assistant.

[andig]

Perfect!