EM2GO Pro Power G2: incorrect charge power / register decoding (Modbus TCP)

[shaensel]

Describe the bug

I'm using an EM2GO Pro Power G2 wallbox with evcc in database mode.

The Modbus TCP communication is working, but the reported charge power is completely unrealistic.

Example:

• charge power: 262144 W
• charge currents: [0 0 0] A
• charger status: A (no car connected)

This indicates that values are read but incorrectly decoded.

Steps to reproduce

1. Install evcc on a Raspberry Pi (database mode, no evcc.yaml)

2. Add a charger in the evcc web UI:

   • Type: EM2GO
   • Model: EM2GO Pro Power G2
   • Connection: Modbus TCP
   • Port: 502
   • Unit ID: 255

3. Ensure the wallbox is powered and connected via Ethernet

4. Do NOT connect a vehicle (charger status should be "A")

5. Start evcc with debug or trace logging:
   evcc -l trace

6. Observe the charger values in evcc UI or logs

Configuration details

- evcc version: (v0.305.1)
- installation: Raspberry Pi, database mode (no evcc.yaml)
- charger: EM2GO Pro Power G2
- connection: Modbus TCP

Log details

[em2go ] TRACE modbus: send 01 e2 00 00 00 06 ff 03 00 6d 00 01
[em2go ] TRACE modbus: recv 01 e2 00 00 00 05 ff 03 02 09 3e

[em2go ] TRACE modbus: send 01 e3 00 00 00 06 ff 03 00 6f 00 01
[em2go ] TRACE modbus: recv 01 e3 00 00 00 05 ff 03 02 09 35

[em2go ] TRACE modbus: send 01 e4 00 00 00 06 ff 03 00 71 00 01
[em2go ] TRACE modbus: recv 01 e4 00 00 00 05 ff 03 02 09 3d

[em2go ] TRACE modbus: send 01 e6 00 00 00 06 ff 03 00 1c 00 02
[em2go ] TRACE modbus: recv 01 e6 00 00 00 07 ff 03 04 00 e9 00 00

What type of operating system or environment does evcc run on?

other

External automation

• I have made sure that no external automation like HomeAssistant or Node-RED is active or accessing any of the mentioned devices when this issue occurs.

Nightly build

• I have verified that the issue is reproducible with the latest nightly build

Version

0.305.1

[RenatusRo]

And in states B or C?

[andig]

The Modbus TCP communication is working

Your screenshot shows OCPP, not Modbus.

[shaensel]

I do not have the car available now.

I added a custom wallbox and the values look plausible, compared to power before ~262kW...

My script looks like this:

type: custom
icon: wallbox
tos: true

status:
  source: js
  script: |
    (function() {
      if (status == 1) return "A";
      if (status == 4) return "C";
      if (status == 2 || status == 3 || status == 6) return "B";
      return "A";
    })()
  in:
    - name: status
      type: int
      config:
        source: modbus
        uri: 192.168.178.105:502
        id: 255
        delay: 60ms
        register:
          address: 0
          type: holding
          encoding: uint16

enabled:
  source: js
  script: |
    command == 1
  in:
    - name: command
      type: int
      config:
        source: modbus
        uri: 192.168.178.105:502
        id: 255
        delay: 60ms
        register:
          address: 95
          type: holding
          encoding: uint16

enable:
  source: js
  script: |
    (function() {
      if (enable) return 1;
      return 2;
    })()
  out:
    - name: enable
      type: int
      config:
        source: modbus
        uri: 192.168.178.105:502
        id: 255
        delay: 60ms
        register:
          address: 95
          type: writemultiple
          encoding: uint16

maxcurrent:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  scale: 10
  register:
    address: 91
    type: writemultiple
    encoding: uint16

maxcurrentmillis:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  scale: 10
  register:
    address: 91
    type: writemultiple
    encoding: uint16

phases1p3p:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  register:
    address: 200
    type: writemultiple
    encoding: uint16

power:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  register:
    address: 12
    type: holding
    encoding: uint32s

energy:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  scale: 0.1
  register:
    address: 28
    type: holding
    encoding: uint32s

currents:
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    scale: 0.1
    register:
      address: 6
      type: holding
      encoding: uint16
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    scale: 0.1
    register:
      address: 8
      type: holding
      encoding: uint16
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    scale: 0.1
    register:
      address: 10
      type: holding
      encoding: uint16

voltages:
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    scale: 0.1
    register:
      address: 109
      type: holding
      encoding: uint16
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    scale: 0.1
    register:
      address: 111
      type: holding
      encoding: uint16
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    scale: 0.1
    register:
      address: 113
      type: holding
      encoding: uint16

powers:
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    register:
      address: 16
      type: holding
      encoding: uint32s
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    register:
      address: 20
      type: holding
      encoding: uint32s
  - source: modbus
    uri: 192.168.178.105:502
    id: 255
    delay: 60ms
    register:
      address: 24
      type: holding
      encoding: uint32s

[RenatusRo]

@andig It is modbus, the OCPP comes from a slightely misleading description in the template:

template: em2go
products:
  - brand: EM2GO
    description:
      generic: Pro Power (OCPP/ONC)
capabilities: ["mA"]
requirements:
  description:
    de: "Aktuelle Firmware mit Modbus-Unterstützung notwendig (Pro Power: 1.01 bzw. OCPP/ONC: 3.15)"
    en: "Recent firmware with Modbus support required (Pro Power: 1.01 and OCPP/ONC: 3.15)"
params:
  - name: modbus
    choice: ["tcpip"]
    id: 255
render: |
  type: em2go
  {{- include "modbus" . }}

[andig]

@naltatis the name is highly confusing and not too helpful.

[andig]

@shaensel evcc uses the same register- seems the em2go sometimes gets confused with the return value?

[shaensel]

Here is the compare between "Custom Wallbox" and "EM2GO Pro Power (OCPP/ONC)":

Custom:
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: send 02 c3 00 00 00 06 ff 03 00 6d 00 01
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: recv 02 c3 00 00 00 05 ff 03 02 09 5b
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: send 02 c4 00 00 00 06 ff 03 00 6f 00 01
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: recv 02 c4 00 00 00 05 ff 03 02 09 63
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: send 02 c5 00 00 00 06 ff 03 00 71 00 01
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: recv 02 c5 00 00 00 05 ff 03 02 09 4e
[lp-1 ] DEBUG 2026/05/04 14:16:47 charge voltages: [240 240 238]V
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: send 02 c6 00 00 00 06 ff 03 00 1c 00 02
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: recv 02 c6 00 00 00 07 ff 03 04 00 ea 00 00
[lp-1 ] DEBUG 2026/05/04 14:16:47 charge total import: 23.400kWh
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: send 02 c7 00 00 00 06 ff 03 00 00 00 01
[db:17 ] TRACE 2026/05/04 14:16:47 modbus: recv 02 c7 00 00 00 05 ff 03 02 00 01
[lp-1 ] DEBUG 2026/05/04 14:16:47 charger status: A

EM2GO:
[em2go ] TRACE 2026/05/04 14:18:41 modbus: send 00 47 00 00 00 06 ff 03 00 6d 00 01
[em2go ] TRACE 2026/05/04 14:18:41 modbus: recv 00 47 00 00 00 05 ff 03 02 09 55
[em2go ] TRACE 2026/05/04 14:18:42 modbus: send 00 48 00 00 00 06 ff 03 00 6f 00 01
[em2go ] TRACE 2026/05/04 14:18:42 modbus: recv 00 48 00 00 00 05 ff 03 02 09 5d
[em2go ] TRACE 2026/05/04 14:18:42 modbus: send 00 49 00 00 00 06 ff 03 00 71 00 01
[em2go ] TRACE 2026/05/04 14:18:42 modbus: recv 00 49 00 00 00 05 ff 03 02 09 41
[lp-2 ] DEBUG 2026/05/04 14:18:42 charge voltages: [239 240 237]V
[em2go ] TRACE 2026/05/04 14:18:42 modbus: send 00 4a 00 00 00 06 ff 03 00 4e 00 02
[em2go ] TRACE 2026/05/04 14:18:42 modbus: recv 00 4a 00 00 00 07 ff 03 04 00 00 00 00
[em2go ] TRACE 2026/05/04 14:18:42 modbus: send 00 4b 00 00 00 06 ff 03 00 1c 00 02
[em2go ] TRACE 2026/05/04 14:18:42 modbus: recv 00 4b 00 00 00 07 ff 03 04 00 ea 00 00
[lp-2 ] DEBUG 2026/05/04 14:18:42 charge total import: 1533542.400kWh
[em2go ] TRACE 2026/05/04 14:18:42 modbus: send 00 4c 00 00 00 06 ff 03 00 00 00 01
[em2go ] TRACE 2026/05/04 14:18:42 modbus: recv 00 4c 00 00 00 05 ff 03 02 00 01
[lp-2 ] DEBUG 2026/05/04 14:18:42 charger status: A

[andig]

So? What does that tell us about power, the topic of this issue? If you have changes identified feel free to open PR!

[RenatusRo]

em2go.go says
em2GoRegEnergy = 28 // Uint16 RO 0.1KWh

vs custom

energy:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  scale: 0.1
  register:
    address: 28
    type: holding
    encoding: uint32s

in the worst case the G2 has really different encoding than 'G1'/home.

[shaensel]

Problem with "Leistung", and here the log for the actual power:

EM2GO
[em2go ] TRACE 2026/05/04 14:25:10 modbus: send 01 28 00 00 00 06 ff 03 00 0c 00 02
[em2go ] TRACE 2026/05/04 14:25:10 modbus: recv 01 28 00 00 00 07 ff 03 04 00 04 00 00
[lp-2 ] DEBUG 2026/05/04 14:25:10 charge power: 262144W

CUSTOM
[db:17 ] TRACE 2026/05/04 14:25:10 modbus: send 01 2a 00 00 00 06 ff 03 00 0c 00 02
[db:17 ] TRACE 2026/05/04 14:25:10 modbus: recv 01 2a 00 00 00 07 ff 03 04 00 04 00 00
[lp-1 ] DEBUG 2026/05/04 14:25:10 charge power: 4W

[shaensel]

em2go.go says em2GoRegEnergy = 28 // Uint16 RO 0.1KWh

vs custom

energy:
  source: modbus
  uri: 192.168.178.105:502
  id: 255
  delay: 60ms
  scale: 0.1
  register:
    address: 28
    type: holding
    encoding: uint32s

in the worst case the G2 has really different encoding than 'G1'/home.

That's what I also think, something is different. Some encoding.

[RenatusRo]

no spec at the web site of d-parts
https://www.d-parts24.de/en-gb/ac-wallbox-pro-power-g2-11kw-7-5m-type-2-cable-lan-wifi-4g-rfid-ocpp-modbus-tcp-mid
and
em2go.de is down
try to ping them