Connecting the Fox ESS Model A wallbox to a HEMS

[steinigermanuel-oss]

Description

I switch the wallbox to UPC mode and enter the HEMS address. The wallbox reports that it is connected. The wallbox is detected in the HEMS under OPPC; it displays "Wallbox detected – please add charging station." When I attempt to add the charging station, it recognizes the wallbox and automatically adopts its ID. However, the app gets stuck in an infinite loop when saving, and the wallbox cannot be saved successfully.

Steps to Reproduce

1. Configure OCPP in the wallbox.
2. Click "Add charging station" in the evcc app.
3. Select "OCPP 1.6" charging station.
4. The wallbox ID is detected automatically. 5. Save... Infinite loop error: wallbox cannot be saved.

Configuration (YAML)

network:
  schema: https
  host: hemspro.local
hems:
  type: relay
  maxPower: 4200       # 1 SteuVE × 4200 W — adjust to grid operator agreement
  limit:
    source: script
    cmd: /usr/local/bin/controlbox-status.sh
    timeout: 5s

Configuration (UI)

{
  "experimental": false,
  "influx": {"url":"","database":"","token":"","org":"","user":"","password":"","insecure":false},
  "interval": 30,
  "meter": [
    {"id":41,"name":"db:41","config":{"baudrate":9600,"comset":"8N1","host":"192.168.178.20","id":71,"modbus":"tcpip","port":1502,"template":"kostal-ksem-inverter","usage":"grid"},"deviceProduct":"Kostal Smart Energy Meter (über den Wechselrichter)","type":"template"},
    {"id":5,"name":"db:5","config":{"baudrate":9600,"capacity":7.2,"comset":"8N1","endianness":"little","host":"192.168.178.20","id":71,"maxacpower":"0","maxsoc":100,"minsoc":5,"modbus":"tcpip","port":1502,"template":"kostal-plenticore-gen2","usage":"battery","watchdog":"60s"},"deviceProduct":"Kostal Plenticore Hybrid, inkl. Netzladung der Hausbatterie","deviceTitle":"Byd","type":"template"},
    {"id":4,"name":"db:4","config":{"baudrate":9600,"comset":"8N1","endianness":"little","host":"192.168.178.20","id":71,"maxacpower":8500,"modbus":"tcpip","port":1502,"template":"kostal-plenticore-gen2","usage":"pv","watchdog":"60s"},"deviceProduct":"Kostal Plenticore Hybrid, inkl. Netzladung der Hausbatterie","deviceTitle":"Wechselrichter","type":"template"}
  ],
  "mqtt": {"broker":"","user":"","password":"","clientID":"","insecure":false,"caCert":"","clientCert":"","clientKey":"","topic":"evcc"},
  "shm": {"vendorId":"","deviceId":"","deviceSerial":""},
  "site": {"title":"","grid":"db:41","pv":["db:4"],"battery":["db:5"],"aux":null,"ext":null},
  "tariff": [
    {"id":9,"name":"db:9","config":{"price":0.26,"template":"fixed"},"deviceProduct":"Fester Preis","type":"template"},
    {"id":8,"name":"db:8","config":{"price":0.11109999999999999,"template":"fixed"},"deviceProduct":"Fester Preis","type":"template"}
  ],
  "tariffRefs": {"grid":"db:9","feedIn":"db:8","co2":"","planner":"","solar":[]}
}

Logs

[site  ] DEBUG 2026/07/10 10:42:30 pv 1 power: 5324W
[site  ] DEBUG 2026/07/10 10:42:30 !! solar production: accumulate set db:4 78790.542kWh meter total (was: Accumulated: 0.147kWh updated: 2026-07-10 10:41:59 +0200 CEST meter: 78790.542kWh)
[site  ] DEBUG 2026/07/10 10:42:30 !! solar production: accumulate moved db:4 from 0.147 to 0.147
[site  ] DEBUG 2026/07/10 10:42:30 site power: -4290W
[script] DEBUG 2026/07/10 10:42:38 /usr/local/bin/controlbox-status.sh: false
[ocpp  ] DEBUG 2026/07/10 10:42:43 charge point disconnected: 60AHD32063BK100
[ocpp  ] DEBUG 2026/07/10 10:42:45 charge point connected: 60AHD32063BK100
[script] DEBUG 2026/07/10 10:42:48 /usr/local/bin/controlbox-status.sh: false
[script] DEBUG 2026/07/10 10:42:58 /usr/local/bin/controlbox-status.sh: false
[site  ] DEBUG 2026/07/10 10:42:59 ----
[gridcontrol] DEBUG 2026/07/10 10:42:59 power: 0W
[gridcontrol] DEBUG 2026/07/10 10:42:59 current: 0A
[site  ] DEBUG 2026/07/10 10:42:59 grid power: -3755W
[site  ] DEBUG 2026/07/10 10:42:59 battery 1 power: -645W
[site  ] DEBUG 2026/07/10 10:42:59 battery 1 soc: 95%
[site  ] DEBUG 2026/07/10 10:42:59 pv 1 power: 5325W
[site  ] DEBUG 2026/07/10 10:43:00 !! solar production: accumulate set db:4 78790.542kWh meter total (was: Accumulated: 0.147kWh updated: 2026-07-10 10:42:30 +0200 CEST meter: 78790.542kWh)
[site  ] DEBUG 2026/07/10 10:43:00 !! solar production: accumulate moved db:4 from 0.147 to 0.147
[site  ] DEBUG 2026/07/10 10:43:00 site power: -4300W
[ocpp  ] DEBUG 2026/07/10 10:43:00 charge point disconnected: 60AHD32063BK100
[ocpp  ] DEBUG 2026/07/10 10:43:02 charge point connected: 60AHD32063BK100
[script] DEBUG 2026/07/10 10:43:08 /usr/local/bin/controlbox-status.sh: false
[ocpp  ] DEBUG 2026/07/10 10:43:17 charge point disconnected: 60AHD32063BK100
[script] DEBUG 2026/07/10 10:43:18 /usr/local/bin/controlbox-status.sh: false
[ocpp  ] DEBUG 2026/07/10 10:43:19 charge point connected: 60AHD32063BK100

Version

v0.304.3

System

linux/arm64, CEST +02:00

[andig]

Traced through the OCPP save flow and your logs. Short version: this isn't evcc getting stuck in a loop — the wallbox is.

60AHD32063BK100 reconnects its WebSocket every 2-15 seconds. Every time it connects, evcc starts a 1-minute wait for the OCPP BootNotification before it considers the charge point usable; every time it disconnects, that wait is reset. Since the wallbox never stays connected for a full minute, BootNotification never completes, so the "Add charging station" Save (which is bounded to ~10s server-side) genuinely times out every time you click it — repeated clicks just look like an infinite loop because the underlying condition never changes.

The fix has to happen on the wallbox/HEMS side: something is causing the Fox ESS Model A's OCPP WebSocket client to drop and reconnect constantly (worth checking its TLS settings, keepalive/ping interval, and whether hemspro.local resolves/round-trips consistently). Once the connection stays up for >1 minute, Save should succeed immediately.

Separately, while investigating this I found and fixed a real (but secondary) evcc bug: after the first failed Save attempt, evcc was caching the half-initialized charge point and skipping the connection wait on subsequent tries. That's fixed in #31652, but it wasn't the primary cause of what you're seeing — the wallbox's flapping connection is.

🤖 Generated with Claude Code

[steinigermanuel-oss]

Thanks for the quick assistance. What exactly do I need to do to fix the problem you described? I can't make any further settings on the wallbox—see the screenshot.

[steinigermanuel-oss]

Hello Andig, I Bring my comment in GitHub. Thanks for your Help Mit freundlichen Grüßen Manuel Steiniger

…

________________________________ From: andig ***@***.***> Sent: Friday, 10 July 2026 11:06:56 To: evcc-io/evcc ***@***.***> Cc: steinigermanuel-oss ***@***.***>; Author ***@***.***> Subject: Re: [evcc-io/evcc] Connecting the Fox ESS Model A wallbox to a HEMS (Issue #31648) [https://avatars.githubusercontent.com/u/184815?s=20&v=4]andig left a comment (evcc-io/evcc#31648)<#31648 (comment)> Traced through the OCPP save flow and your logs. Short version: this isn't evcc getting stuck in a loop — the wallbox is. 60AHD32063BK100 reconnects its WebSocket every 2-15 seconds. Every time it connects, evcc starts a 1-minute wait for the OCPP BootNotification before it considers the charge point usable; every time it disconnects, that wait is reset. Since the wallbox never stays connected for a full minute, BootNotification never completes, so the "Add charging station" Save (which is bounded to ~10s server-side) genuinely times out every time you click it — repeated clicks just look like an infinite loop because the underlying condition never changes. The fix has to happen on the wallbox/HEMS side: something is causing the Fox ESS Model A's OCPP WebSocket client to drop and reconnect constantly (worth checking its TLS settings, keepalive/ping interval, and whether hemspro.local resolves/round-trips consistently). Once the connection stays up for >1 minute, Save should succeed immediately. Separately, while investigating this I found and fixed a real (but secondary) evcc bug: after the first failed Save attempt, evcc was caching the half-initialized charge point and skipping the connection wait on subsequent tries. That's fixed in #31652<#31652>, but it wasn't the primary cause of what you're seeing — the wallbox's flapping connection is. 🤖 Generated with Claude Code<https://claude.com/claude-code> — Reply to this email directly, view it on GitHub<#31648?email_source=notifications&email_token=CIAMIQXGDBCAPIJC3QC6IW35ECW3BA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOJTGM3TONBUGI42M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2KYZTPN52GK4S7MNWGSY3L#issuecomment-4933774429>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/CIAMIQQXAGHTAI533HYLD7L5ECW3BAVCNFSNUABFKJSXA33TNF2G64TZHMZDENRTGY4DGMZYHNEXG43VMU5TIOBVGM2TGNJXGE42C5QC>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS<https://github.com/notifications/mobile/ios/CIAMIQX36CKBEZWJP52EYAD5ECW3BA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOJTGM3TONBUGI42M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2KUZTPN52GK4S7NFXXG> and Android<https://github.com/notifications/mobile/android/CIAMIQVVA2VRDAL3APE4MBD5ECW3BA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOJTGM3TONBUGI42M4TFMFZW63VGMF2XI2DPOKSWK5TFNZ2K4ZTPN52GK4S7MFXGI4TPNFSA>. Download it today! You are receiving this because you authored the thread.Message ID: ***@***.***>

[andig]

Open issue with Fox- it's their charger that drops the connection. Or wait until #31412 completes.

[steinigermanuel-oss]

Okay, I understand. Will #31412 fix the problem? Can you say roughly when that will be? Mit freundlichen Grüßen Manuel Steiniger

…

________________________________ From: andig ***@***.***> Sent: Friday, 10 July 2026 12:10:45 To: evcc-io/evcc ***@***.***> Cc: steinigermanuel-oss ***@***.***>; Author ***@***.***> Subject: Re: [evcc-io/evcc] Connecting the Fox ESS Model A wallbox to a HEMS (Issue #31648) Closed #31648<#31648> as completed. — Reply to this email directly, view it on GitHub<#31648?email_source=notifications&email_token=CIAMIQW6ORCXUJXOT2QKJDL5EC6KLA5CNFSNUABQM5UWIORPF5TWS5BNNB2WEL2JONZXKZKFOZSW45CON52GSZTJMNQXI2LPNYXTENZYGA4DCOBXGAYDFJTSMVQXG33OUZQXK5DIN5ZKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#event-27808187002>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/CIAMIQXMRJO6ZGI5CA6P4BT5EC6KLAVCNFSNUABFKJSXA33TNF2G64TZHMZDENRTGY4DGMZYHNEXG43VMU5TIOBVGM2TGNJXGE42C5QC>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS<https://github.com/notifications/mobile/ios/CIAMIQQDPZMSDPJC6XMLCX35EC6KLA5CNFSNUABQM5UWIORPF5TWS5BNNB2WEL2JONZXKZKFOZSW45CON52GSZTJMNQXI2LPNYXTENZYGA4DCOBXGAYDFJTSMVQXG33OUZQXK5DIN5ZKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android<https://github.com/notifications/mobile/android/CIAMIQQBA2GHD7F2J5CZ4QL5EC6KLA5CNFSNUABQM5UWIORPF5TWS5BNNB2WEL2JONZXKZKFOZSW45CON52GSZTJMNQXI2LPNYXTENZYGA4DCOBXGAYDFJTSMVQXG33OUZQXK5DIN5ZKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you authored the thread.Message ID: ***@***.***>

[GurliGebis]

@steinigermanuel-oss I'm working on it - it will be at least a week, since we need to get our EV first (on Friday), so I can test.

[steinigermanuel-oss]

Hi GurliGebis, have you found a solution to the problem yet? Mit freundlichen Grüßen Manuel Steiniger

…

________________________________ From: GurliGebis ***@***.***> Sent: Saturday, 11 July 2026 21:50:56 To: evcc-io/evcc ***@***.***> Cc: steinigermanuel-oss ***@***.***>; Mention ***@***.***> Subject: Re: [evcc-io/evcc] Connecting the Fox ESS Model A wallbox to a HEMS (Issue #31648) [https://avatars.githubusercontent.com/u/13592619?s=20&v=4]GurliGebis left a comment (evcc-io/evcc#31648)<#31648 (comment)> @steinigermanuel-oss<https://github.com/steinigermanuel-oss> I'm working on it - it will be at least a week, since we need to get our EV first (on Friday), so I can test. — Reply to this email directly, view it on GitHub<#31648?email_source=notifications&email_token=CIAMIQSXUYRP4XWYR24TX435EKLCBA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOJUHA2TGNZTGQYKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-4948537340>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/CIAMIQVFFR25ZF5A5CNZYQT5EKLCBAVCNFSNUABFKJSXA33TNF2G64TZHMZDENRTGY4DGMZYHNEXG43VMU5TIOBVGM2TGNJXGE42C5QC>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS<https://github.com/notifications/mobile/ios/CIAMIQROWKGVJ6EONUTATDT5EKLCBA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOJUHA2TGNZTGQYKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android<https://github.com/notifications/mobile/android/CIAMIQUZRUECQZNZAVHLC535EKLCBA5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTIOJUHA2TGNZTGQYKM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>

[GurliGebis]

It works fine for me, but the pull request needs to be reviewed and merged, followed by a new release for it to be available.

[steinigermanuel-oss]

OK, great, thanks. Mit freundlichen Grüßen Manuel Steiniger

…

________________________________ From: GurliGebis ***@***.***> Sent: Wednesday, 22 July 2026 12:18:55 To: evcc-io/evcc ***@***.***> Cc: steinigermanuel-oss ***@***.***>; Mention ***@***.***> Subject: Re: [evcc-io/evcc] Connecting the Fox ESS Model A wallbox to a HEMS (Issue #31648) [https://avatars.githubusercontent.com/u/13592619?s=20&v=4]GurliGebis left a comment (evcc-io/evcc#31648)<#31648 (comment)> It works fine for me, but the pull request needs to be reviewed and merged, followed by a new release for it to be available. — Reply to this email directly, view it on GitHub<#31648?email_source=notifications&email_token=CIAMIQSSBP4ON4IJIDOIHAT5GCII7A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBUGQ3DGNRVG43KM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-5044636576>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/CIAMIQT3TE2LOLVVKBJBT6T5GCII7AVCNFSNUABFKJSXA33TNF2G64TZHMZDENRTGY4DGMZYHNEXG43VMU5TIOBVGM2TGNJXGE42C5QC>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS<https://github.com/notifications/mobile/ios/CIAMIQSI5ZLPUC4WOY24DDT5GCII7A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBUGQ3DGNRVG43KM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android<https://github.com/notifications/mobile/android/CIAMIQXOUXUJ5KHQIL5LBID5GCII7A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBUGQ3DGNRVG43KM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.Message ID: ***@***.***>

[steinigermanuel-oss]

Hi GurliGebis, when do you think the new app version is coming? Mit freundlichen Grüßen Manuel Steiniger

…

________________________________ Von: Manuel Steiniger ***@***.***> Gesendet: Mittwoch, Juli 22, 2026 2:52:36 PM An: evcc-io/evcc ***@***.***>; evcc-io/evcc ***@***.***> Cc: Mention ***@***.***> Betreff: Re: [evcc-io/evcc] Connecting the Fox ESS Model A wallbox to a HEMS (Issue #31648) OK, great, thanks. Mit freundlichen Grüßen Manuel Steiniger

________________________________ From: GurliGebis ***@***.***> Sent: Wednesday, 22 July 2026 12:18:55 To: evcc-io/evcc ***@***.***> Cc: steinigermanuel-oss ***@***.***>; Mention ***@***.***> Subject: Re: [evcc-io/evcc] Connecting the Fox ESS Model A wallbox to a HEMS (Issue #31648) [https://avatars.githubusercontent.com/u/13592619?s=20&v=4]GurliGebis left a comment (evcc-io/evcc#31648)<#31648 (comment)> It works fine for me, but the pull request needs to be reviewed and merged, followed by a new release for it to be available. — Reply to this email directly, view it on GitHub<#31648?email_source=notifications&email_token=CIAMIQSSBP4ON4IJIDOIHAT5GCII7A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBUGQ3DGNRVG43KM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLDGN5XXIZLSL5RWY2LDNM#issuecomment-5044636576>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/CIAMIQT3TE2LOLVVKBJBT6T5GCII7AVCNFSNUABFKJSXA33TNF2G64TZHMZDENRTGY4DGMZYHNEXG43VMU5TIOBVGM2TGNJXGE42C5QC>. Triage notifications, keep track of coding agent tasks and review pull requests on the go with GitHub Mobile for iOS<https://github.com/notifications/mobile/ios/CIAMIQSI5ZLPUC4WOY24DDT5GCII7A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBUGQ3DGNRVG43KM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJKTGN5XXIZLSL5UW64Y> and Android<https://github.com/notifications/mobile/android/CIAMIQXOUXUJ5KHQIL5LBID5GCII7A5CNFSNUABFM5UWIORPF5TWS5BNNB2WEL2JONZXKZKDN5WW2ZLOOQXTKMBUGQ3DGNRVG43KM4TFMFZW63VHNVSW45DJN5XKKZLWMVXHJLTGN5XXIZLSL5QW4ZDSN5UWI>. Download it today! You are receiving this because you were mentioned.

[GurliGebis]

It is still being worked on - if you want, you can follow along at #31412 🙂