automatic 1p/3p switch stops working after a while (openWB)

[sledge2019]

Describe the bug

When running EVCC for some time, the automatic switch from 1p to 3p stops working - usually I have to reboot the evcc every 24-48 hours to get it going again. This behavious shows since I started to use EVCC almsot 12 months ago.

My setup:
EVCC 0.309.2 VM on proxmox with 256mb RAM and 4GB bootdisk size
openWB series 2 mit SW 2.0 (multiple versions tried, no change) as secondary

When using openWB as standalone solution, the 1p/3p switch works like a charme - so I am confident to rule out a hardware issue with openWB or together with my BEV.

Logfiles attached (the older one shows that evcc was charging with 3p successfully at the beginning).

Any push into the right direction appreciated.

evcc-20260705-133057-debug.log

evcc-20260705-132153-debug.log

Steps to reproduce

1. Plug in the car (was plugged from yesterday)
2. Hope for enough sunshine
3. Sometimes the 1p/3p switch works, sometimes it stops working.
   ...

Configuration details

root@evcc:/# evcc config --database /var/lib/evcc/evcc.db 
[main  ] INFO 2026/07/05 13:40:31 config file not found, database-only mode
[main  ] INFO 2026/07/05 13:40:31 using sqlite database: /var/lib/evcc/evcc.db?_pragma=busy_timeout(5000)&_pragma=foreign_keys(1)&_pragma=auto_vacuum(INCREMENTAL)
charger
---
db:1 {Type:template Title: Icon: Product:openWB Software 2.x} map[baudrate:9600 comset:8N1 connector:1 host:openwb.seconet.de id:1 modbus:tcpip phases1p3p:true port:1502 template:openwb-2.0]

meter
---
db:3 {Type:template Title: Icon: Product:Victron Energy} map[host:victron.seconet.de maxacpower:0 port:502 template:victron-energy usage:grid]
db:4 {Type:template Title:PV Icon: Product:Victron Energy} map[host:victron.seconet.de maxacpower:0 port:502 template:victron-energy usage:pv]
db:5 {Type:template Title:Batterie Icon: Product:Victron Energy} map[capacity:15 host:victron.seconet.de maxacpower:0 minsoc:20 port:502 template:victron-energy usage:battery]

vehicle
---
db:8 {Type:template Title: Icon: Product:TeslaMate} map[capacity:55 icon:car id:1 template:teslamate timeout:720h title:Tesla Model 3]

tariff
---
db:7 {Type:template Title:PV-Vorhersage Icon: Product:Victron VRM Solar Forecast} map[idsite:173169 interval:1h template:victron token:*****]
db:9 {Type:template Title: Icon: Product:Fester Preis} map[price:0.3 template:fixed]
db:10 {Type:template Title: Icon: Product:Fester Preis} map[price:0.12 template:fixed]
db:11 {Type:template Title: Icon: Product:Grünstromindex} map[template:grünstromindex zip:*****]

loadpoint
---
db:2 {Type: Title: Icon: Product:} map[batteryBoostLimit:80 charger:db:1 circuit: defaultMode:pv meter: minCurrent:6 mode:now phasesConfigured:0 planStrategy:map[continuous:false precondition:0] soc:map[estimate:true poll:map[interval:3.6e+12 mode:charging]] thresholds:map[disable:map[delay:1.8e+11 threshold:0] enable:map[delay:6e+10 threshold:0]] title:Garage ui:map[maxTemp:0 minTemp:0] vehicle:db:8]

Log details

See the attached logfiles - but here the jounalctl output:

root@evcc:/# sudo journalctl -u evcc -S "2026-07-01 07:00:00" -U "2026-07-05 13:35:00" 
Jul 01 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/01 10:02:33 new version available: 0.310.1
Jul 01 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/01 16:02:33 new version available: 0.310.1
Jul 01 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/01 22:02:33 new version available: 0.310.1
Jul 02 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 04:02:33 new version available: 0.310.1
Jul 02 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 10:02:33 new version available: 0.310.1
Jul 02 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 16:02:33 new version available: 0.310.1
Jul 02 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 22:02:33 new version available: 0.310.1
Jul 03 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 04:02:33 new version available: 0.310.1
Jul 03 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 10:02:33 new version available: 0.310.1
Jul 03 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 16:02:33 new version available: 0.310.1
Jul 03 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 22:02:33 new version available: 0.310.1
Jul 04 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 04:02:33 new version available: 0.310.1
Jul 04 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 10:02:33 new version available: 0.310.1
Jul 04 14:52:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:52:04 car connected
Jul 04 14:52:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:52:34 start charging ->
Jul 04 14:54:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:54:04 stop charging <-
Jul 04 14:55:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:55:04 start charging ->
Jul 04 15:36:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:36:04 stop charging <-
Jul 04 15:36:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:36:04 car disconnected
Jul 04 15:54:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:54:04 car connected
Jul 04 15:54:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:54:34 start charging ->
Jul 04 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 16:02:33 new version available: 0.310.1
Jul 04 17:24:27 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 17:24:27 stop charging <-
Jul 04 17:24:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 17:24:34 start charging ->
Jul 04 18:55:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 18:55:04 stop charging <-
Jul 04 19:00:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 19:00:34 start charging ->
Jul 04 19:26:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 19:26:04 stop charging <-
Jul 04 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 22:02:33 new version available: 0.310.1
Jul 05 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/05 04:02:33 new version available: 0.310.1
Jul 05 09:50:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 09:50:04 start charging ->
Jul 05 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/05 10:02:33 new version available: 0.310.1
Jul 05 11:35:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 11:35:34 stop charging <-
Jul 05 12:08:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:08:34 start charging ->
Jul 05 12:23:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:23:04 stop charging <-
Jul 05 12:27:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:27:04 start charging ->
root@evcc:/# sudo journalctl -u evcc -S "2026-07-01 07:00:00" -U "2026-07-05 13:35:00" -q
Jul 01 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/01 10:02:33 new version available: 0.310.1
Jul 01 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/01 16:02:33 new version available: 0.310.1
Jul 01 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/01 22:02:33 new version available: 0.310.1
Jul 02 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 04:02:33 new version available: 0.310.1
Jul 02 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 10:02:33 new version available: 0.310.1
Jul 02 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 16:02:33 new version available: 0.310.1
Jul 02 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/02 22:02:33 new version available: 0.310.1
Jul 03 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 04:02:33 new version available: 0.310.1
Jul 03 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 10:02:33 new version available: 0.310.1
Jul 03 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 16:02:33 new version available: 0.310.1
Jul 03 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/03 22:02:33 new version available: 0.310.1
Jul 04 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 04:02:33 new version available: 0.310.1
Jul 04 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 10:02:33 new version available: 0.310.1
Jul 04 14:52:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:52:04 car connected
Jul 04 14:52:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:52:34 start charging ->
Jul 04 14:54:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:54:04 stop charging <-
Jul 04 14:55:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 14:55:04 start charging ->
Jul 04 15:36:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:36:04 stop charging <-
Jul 04 15:36:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:36:04 car disconnected
Jul 04 15:54:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:54:04 car connected
Jul 04 15:54:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 15:54:34 start charging ->
Jul 04 16:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 16:02:33 new version available: 0.310.1
Jul 04 17:24:27 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 17:24:27 stop charging <-
Jul 04 17:24:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 17:24:34 start charging ->
Jul 04 18:55:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 18:55:04 stop charging <-
Jul 04 19:00:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 19:00:34 start charging ->
Jul 04 19:26:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/04 19:26:04 stop charging <-
Jul 04 22:02:33 evcc evcc[154]: [main  ] INFO 2026/07/04 22:02:33 new version available: 0.310.1
Jul 05 04:02:33 evcc evcc[154]: [main  ] INFO 2026/07/05 04:02:33 new version available: 0.310.1
Jul 05 09:50:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 09:50:04 start charging ->
Jul 05 10:02:33 evcc evcc[154]: [main  ] INFO 2026/07/05 10:02:33 new version available: 0.310.1
Jul 05 11:35:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 11:35:34 stop charging <-
Jul 05 12:08:34 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:08:34 start charging ->
Jul 05 12:23:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:23:04 stop charging <-
Jul 05 12:27:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:27:04 start charging ->
Jul 05 12:39:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:39:04 stop charging <-
Jul 05 12:51:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 12:51:04 start charging ->
Jul 05 13:02:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 13:02:04 stop charging <-
Jul 05 13:12:04 evcc evcc[154]: [lp-1  ] INFO 2026/07/05 13:12:04 start charging ->

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

evcc version 0.309.2 (e4316fd)

[andig]

Could you please test if the PR works for you? Since this is very old code I'm reluctant merging it without test.

[sledge2019]

Ok, took me some time to build evcc from source with the pull-request. (cloning, setting up go, npm etc on a fresh debian VM, etc)

Server is up and running, will wait for it to happen again.

I hope I didn't mix it up and have the correct version up and running now.

[sledge2019]

Yesterday was a perfect day to test the 1p / 3p switches - While I checked evcc managed that transistion more than 5 times without any issues, additionally I used "heating up the pool" and "charging the battery" to "downshift" to 1p, only to see evv switching to 3p a couple of minutes later again.

No "being stuck on 1p" anymore.

From my persepctive and one day of testing it seems to work.

More testing tomorrow. But it looks very promising from my pov.

[andig]

I've rethought this and we really can't do this. The PR uses "measured" phases as criteria for re-forcing the 3p switch and that's not correct. If you switch to 3p and still see 1p measured that may be perfectly valid, for example if the car is 1p. The only way to properly fix this is by reading the switched phases from OpenWB. If anybody knows if there's a modbus register for that we can give it another try. The current PR seems wrong.

[sledge2019]

Hmmm, the only source I found is this one - but I am sure you already have that information.

https://wiki.openwb.de/doku.php?id=openwb:vc:2.2.0:api#openwb_modbus_rev20_im_secondary_mode

If the registers 10180 and 10181 do not provide the required information, then I guess I am out of luck.

For the time being I would stay on this version as it works for me, the only alternative would be changing back to the openWB version - which I want to avoid for UI/UX reasons.

Would evcc on "baremetal" openwb change this problem? There is no shortage on micro-SD cards here, but since my openWB is kind of hard to reach, I try to avoid this step.

[andig]

Did you open a ticket that phaseswitch sometimes doesn‘t work? As for bare metal: probably as we‘re talking to the controller directly.

[sledge2019]

Nope, I did not raise that topic in the openwb Forums or create a ticket on openwb side.

Based on your assumption I'll try the baremetal solution over the weekend.

[sledge2019]

Ok - just to record the current status. Installed openwb embedded Software replacement successfully, successfully migrated my charging history and got everything up and running. Would love to charge now, but the car is 100% charged...

Let's see how things work out.

[andig]

/cc @snaptec see my question regarding reading phase status via modbus.

[andig]

@sledge2019 could you also produce an interal log of the original obenWB when the switching fails and send to support?

[sledge2019]

@sledge2019 could you also produce an interal log of the original obenWB when the switching fails and send to support?

No problem. Let's first check if the "baremetal" solution works as desired. If the problem remains, I am back to square one anyway.