Zaptec Go charger oauth2: cannot fetch token: 503 Service Unavailable

[rea7mic]

Describe the bug

My Zaptec Go charger is „offline“ in evcc and log reports „oauth2: cannot fetch token: 503 Service Unavailable“.

I had already try to reconnect, re-create and validate the charger, but error message is still present. The extra Zaptec user and password are ok, login via Webportal or iOS App works.

On Zaptec Webportal there was some news about security changes, not sure is that the root cause under evcc?
https://help.zaptec.com/hc/en-001/articles/40356875306513-Can-t-log-in-Update-your-Zaptec-App

I had removed the Charger from WebUI to test everything from the beginning, but no luck and sorry, you can see it in the shared config/logs, the original Loadpoint and Charger was removed and the new ones I can‘t add because validate process failed.

Can someone with Zaptec Go charger reproduce the issue? Maybe with creating a second Chargepoint.
My config is running on Raspi and I‘m using WebUI config only. Thx

Steps to reproduce

1. Go to Configuration
2. select Charging point settings
3. select Charger Zaptec Go and click settings
4. click on validate

Configuration details

## Configuration (YAML)


# open evcc at http://evcc.local:7070
network:
  schema: http
  host: evcc.local # .local suffix announces the hostname on MDNS
  port: 7070
log: debug
levels:
  cache: error
# unique installation id
plant: *****
interval: 10s # control cycle interval


## Configuration (UI)


{
  "site": {
    "title": "Gerstungen (DE-GER-MS2)",
    "grid": "db:11",
    "pv": ["db:4"],
    "battery": null,
    "aux": null,
    "ext": null
  },
  "loadpoints": [
    {"id":9,"name":"db:9","charger":"db:8","vehicle":"db:10","title":"AVM FRITZ!DECT 210 (Garage)","defaultMode":"off","priority":0,"phasesConfigured":1,"minCurrent":10,"maxCurrent":10,"smartCostLimit":0.08,"smartFeedInPriorityLimit":null,"planEnergy":0,"planTime":"0001-01-01T00:00:00Z","planPrecondition":0,"limitEnergy":0.15,"limitSoc":0,"thresholds":{"enable":{"delay":60000000000,"threshold":0},"disable":{"delay":180000000000,"threshold":0}},"soc":{"poll":{"mode":"charging","interval":3600000000000},"estimate":true}}
  ],
  "charger": [
    {"config":{"ain":"***","icon":"scooter","password":"***","standbypower":"15","template":"fritzdect","uri":"https://192.168.1.2","user":"evcc"},"deviceProduct":"AVM FritzDECT","id":8,"name":"db:8","type":"template"},
    {"config":{"id":"0..f","password":"***","template":"zaptec","user":"muehlen-demos.0m@icloud.com"},"deviceProduct":"Zaptec Go","id":16,"name":"db:16","type":"template"},
    {"config":{"id":"0..f","password":"***","template":"zaptec","user":"muehlen-demos.0m@icloud.com"},"deviceProduct":"Zaptec Go","id":20,"name":"db:20","type":"template"},
    {"config":{"id":"0..f","passive":false,"password":"***","template":"zaptec","user":"muehlen-demos.0m@icloud.com"},"deviceProduct":"Zaptec Go","id":25,"name":"db:25","type":"template"},
    {"config":{"id":"0..f","password":"***","template":"zaptec","user":"muehlen-demos.0m@icloud.com"},"deviceProduct":"Zaptec Go","id":30,"name":"db:30","type":"template"}
  ],
  "meter": [
    {"config":{"host":"192.168.1.105","template":"sma-home-manager","usage":"grid"},"deviceProduct":"SMA Sunny Home Manager 2.0","id":11,"name":"db:11","type":"template"},
    {"config":{"capacity":0,"host":"192.168.1.106","password":"***","template":"sma-inverter-speedwire","usage":"pv"},"deviceProduct":"SMA Inverter (Speedwire)","deviceTitle":"SMA SUNNY TRIPOWER 10.0SE","id":4,"name":"db:4","type":"template"}
  ],
  "vehicle": [
    {"config":{"capacity":0.28,"icon":"scooter","mode":"pv","phases":"1","template":"offline","title":"Micro Explorer"},"deviceProduct":"Generic vehicle","id":10,"name":"db:10","type":"template"},
    {"config":{"capacity":37.9,"clientid":"9..d","icon":"car","identifiers":["nfc-A..C"],"maxCurrent":32,"minCurrent":6,"mode":"pv","phases":"","priority":10,"streaming":true,"template":"cardata","title":"BMW i3s 120","vin":"W..9"},"deviceProduct":"BMW CarData (EU Data Act)","id":14,"name":"db:14","type":"template"},
    {"config":{"capacity":80.7,"clientid":"9..d","icon":"car","identifiers":["nfc-A..C"],"maxCurrent":32,"minCurrent":6,"mode":"pv","phases":"","priority":10,"streaming":true,"template":"cardata","title":"BMW i4 M50","vin":"W..8"},"deviceProduct":"BMW CarData (EU Data Act)","id":15,"name":"db:15","type":"template"}
  ],
  "circuits": "- name: main # unique name, used as reference, e.g. as parent in other circuits
  title: Main Circuit # used in the UI
  maxcurrent: 50 # 50A main circuit breaker (optional)
  maxPower: 32000 # 32kW (optional)
  meter: db:11 # associated meter to monitor the power consumption (optional)
#  parent: # no parent, this is the root circuit
- name: db:3 # unique name, used as reference, e.g. to associate loadpoints
  title: Zaptec Go (Public) # used in the UI
  maxcurrent: 20 # allow individual phase use up to 20A
  maxPower: 11040 # limit total power to 11kW
#  meter: garage # dedicated meter for the garage
  parent: main # parent to the main circuit
#- name: carport # unique name, used as reference, e.g. to associate loadpoints
#  title: Carport # used in the UI
#  maxCurrent: 32 # 32A circuit breaker
#  maxPower: # no limit, only check current
#  meter: # no meter, using data from loadpoints
#  parent: main # parent to the main circuit",
  "hems": "#type: relay
#maxPower: 8400 # Gesamtleistungslimit bei aktivem Signal (in Watt)
#limit:
  # Plugin-spezifische Konfiguration",
  "tariffs": "currency: EUR
grid:
    #type: fixed
    #price: 0.280 # EUR/kWh
    type: template
    template: tibber
    token: 22..L_ato
    homeid: 1..7bd
feedin:
    type: fixed
    price: 0.08 # EUR/kWh
co2:
    type: template
    template: green-grid-compass
    apiKey: owF..XOXBm4hR
    zone: DE_LU
planner:
    type: \"\"
solar:
    type: template
    template: open-meteo
    lat: 50.9688
    lon: 10.0785
    dec: 12
    kwp: 10.20
    az: 50
    dm: 0
    de: 0
    efficiency: 100
    alphatemp: -0.004
    rossmodel: 0.0563
    interval: 1h"
}

Log details

## Logs


[lp-2  ] DEBUG 2025/11/05 11:28:02 charge power: 0W
[lp-1  ] ERROR 2025/11/05 11:28:10 charge power: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: cannot fetch token: 503 Service Unavailable
Response: <html>
<head><title>503 Service Temporarily Unavailable</title></head>
<body>
<center><h1>503 Service Temporarily Unavailable</h1></center>
<hr><center>nginx/1.29.0</center>
</body>
</html>
[lp-1  ] ERROR 2025/11/05 11:28:18 charge currents: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: cannot fetch token: 503 Service Unavailable
Response: <html>
<head><title>503 Service Temporarily Unavailable</title></head>
<body>
<center><h1>503 Service Temporarily Unavailable</h1></center>
<hr><center>nginx/1.29.0</center>
</body>
</html>
[circuit-db:3] DEBUG 2025/11/05 11:28:18 power: 0W
[circuit-db:3] DEBUG 2025/11/05 11:28:18 current: 0A
[circuit-main] DEBUG 2025/11/05 11:28:18 power: 135W
[circuit-main] DEBUG 2025/11/05 11:28:18 current: 5.05A
[site  ] DEBUG 2025/11/05 11:28:18 grid power: 135W
[site  ] DEBUG 2025/11/05 11:28:18 grid powers: [-781 1097 -181]W
[site  ] DEBUG 2025/11/05 11:28:18 grid currents: [-3.85 5.05 -2.07]A
[site  ] DEBUG 2025/11/05 11:28:18 pv 1 power: 3436W
[site  ] DEBUG 2025/11/05 11:28:18 !! solar production: accumulate set db:4 12932.838kWh meter total (was: Accumulated: 4252.356kWh updated: 2025-11-05 11:28:02 +0100 CET meter: 12932.824kWh)
[site  ] DEBUG 2025/11/05 11:28:18 !! solar production: accumulate moved db:4 from 4252.356 to 4252.370
[site  ] DEBUG 2025/11/05 11:28:18 site power: 535W
[lp-2  ] DEBUG 2025/11/05 11:28:19 charge total import: 1299.907kWh
[lp-2  ] DEBUG 2025/11/05 11:28:21 charger status: B
[lp-2  ] DEBUG 2025/11/05 11:28:22 pv charge current: 0A = 0A + -2.33A (535W @ 1p)
[lp-2  ] DEBUG 2025/11/05 11:28:22 projected site power 535W >= 0W disable threshold
[lp-2  ] DEBUG 2025/11/05 11:28:22 pv disable in 1m7s
[lp-2  ] DEBUG 2025/11/05 11:28:22 pv disable timer remaining: 1m7s
[site  ] DEBUG 2025/11/05 11:28:22 solar forecast: accumulated 0.022Wh from 2025-11-05 11:28:02 +0100 CET to 2025-11-05 11:28:22 +0100 CET
[site  ] DEBUG 2025/11/05 11:28:22 solar forecast: produced 4252.370
[site  ] DEBUG 2025/11/05 11:28:22 solar forecast: accumulated 4702.661kWh, produced 4252.370kWh, scale 0.904
[site  ] DEBUG 2025/11/05 11:28:22 ----
[lp-2  ] DEBUG 2025/11/05 11:28:23 charge power: 0W

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

Linux

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

v0.209.6

[chris-e-codes]

Same here, but I opened a ticket at Zaptec. Let’s see what they say.
But yeah could also relate to their changes 🤷‍♂️

[rea7mic]

UPDATE: reboot of evcc solved the issue on my side - after the charger was removed, i created a new one and this time the validation works

[chris-e-codes]

I think Zaptec fixed it. No change at my side. Just works again

[rea7mic]

Issue is solved. Perfect 🤓

[chris-e-codes]

It starts again. Hmmm strange…

[rea7mic]

Same on my side 503 error is back - restart of evcc service doesn't help.

[lp-1 ] ERROR 2025/11/07 13:51:56 charge power: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: cannot fetch token: 503 Service Unavailable Response: <html>
 <head><title>503 Service Temporarily Unavailable</title></head>
 <body>
 <center><h1>503 Service Temporarily Unavailable</h1></center>
 <hr><center>nginx/1.29.0</center>
 </body>
 </html>
[lp-1 ] ERROR 2025/11/07 13:52:05 charge currents: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: cannot fetch token: 503 Service Unavailable Response: <html>
 <head><title>503 Service Temporarily Unavailable</title></head>
 <body>
 <center><h1>503 Service Temporarily Unavailable</h1></center>
 <hr><center>nginx/1.29.0</center>
 </body>
 </html>

[StefanSchoof]

503 Service Temporarily Unavailable

That is a problem on the sever side of Zaptec.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status/503

[rea7mic]

after some minutes the connection is working - yes, issue is located on Zaptec side

Nov  7 13:49:17 ger-hoobs1 evcc[26196]: [lp-1  ] ERROR 2025/11/07 13:49:17 charge power: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: "invalid_grant" "The specified refresh token is invalid." "https://documentation.openiddict.com/errors/ID2003"
Nov  7 13:49:25 ger-hoobs1 evcc[26196]: [lp-1  ] ERROR 2025/11/07 13:49:25 charge currents: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: cannot fetch token: 503 Service Unavailable
..
Nov  7 13:54:54 ger-hoobs1 evcc[26196]: [lp-1  ] ERROR 2025/11/07 13:54:54 charge currents: Get "https://api.zaptec.com/api/chargers/0..f/state": oauth2: cannot fetch token: 503 Service Unavailable
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set title: Zaptec Go (Public)
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set priority: 10
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set smart cost limit: 0.2
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set smart feed-in limit: <nil>
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set thresholds: {Enable:{Delay:5m0s Threshold:-2000} Disable:{Delay:1m0s Threshold:0}}
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set plan energy: 0kWh @ 0001-01-01 00:53:28 +0053 LMT
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set session energy limit: 0
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set session soc limit: 0
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set soc config: {Poll:{Mode:charging Interval:1h0m0s} Estimate:0x77ed6f8}
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set default mode: off
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set phases: 3
Nov  7 13:55:08 ger-hoobs1 evcc[32174]: [lp-1  ] DEBUG 2025/11/07 13:55:08 set max current: 20
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set title: Zaptec Go (Public)
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set priority: 10
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set smart cost limit: 0.2
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set smart feed-in limit: <nil>
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set thresholds: {Enable:{Delay:5m0s Threshold:-2000} Disable:{Delay:1m0s Threshold:0}}
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set plan energy: 0kWh @ 0001-01-01 00:53:28 +0053 LMT
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set session energy limit: 0
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set session soc limit: 0
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set soc config: {Poll:{Mode:charging Interval:1h0m0s} Estimate:0x6c26d38}
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set default mode: off
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set phases: 3
Nov  7 13:55:39 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:39 set max current: 20
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] INFO 2025/11/07 13:55:47 loadpoint 1:
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] INFO 2025/11/07 13:55:47   mode:        off
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] INFO 2025/11/07 13:55:47   charger:     power ✓ energy ✗ currents ✓ phases ✓ wakeup ✗
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] INFO 2025/11/07 13:55:47   meters:      charge ✓
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] INFO 2025/11/07 13:55:47     charge:    power ✓ energy ✗ currents ✓
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:47 set smart cost limit: 0.2
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:47 phase timer inactive
Nov  7 13:55:47 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:47 pv timer inactive
Nov  7 13:55:48 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:48 charge power: 0W
Nov  7 13:55:48 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:48 charge currents: [0.056 0.051 0.332]A
Nov  7 13:55:48 ger-hoobs1 evcc[32233]: [lp-1  ] DEBUG 2025/11/07 13:55:48 charger status: A
Nov  7 13:55:48 ger-hoobs1 evcc[32233]: [lp-1  ] INFO 2025/11/07 13:55:48 car disconnected

[baszalmstra]

I am still facing this issue.

[chris-e-codes]

ja bei Zaptec ist die API Verfügbarkeit gerade echt unbrauchbar.
Geht / Geht nicht / geht nicht / geht nicht / geht
etc.
Support meint noch die API wäre funktionstüchtig. Habe dann mal ein paar Tests hinterhergeschickt, bei denen man sieht, dass es wackelt. Mal sehen.

[baszalmstra]

Removing the charging from the config and adding the charger back through the ui seems to have worked

[chris-e-codes]

but thats just temporary. The Zaptec API ist an on/off problem yet. In 10 Minutes everything could be different.