[HA Feature] Add Discharge Cut-Off Voltage settings

[pilot51]

Feature Name

On-Grid/Off-Grid Discharge Cut-off Voltage Limit

Is this an Entity?

Yes

Feature Description

Much like the On-grid Discharge Cut-off SOC Limit and Off-grid Discharge Cut-off SOC Limit entities, I would like entities added for the voltage limits as well.

MQTT exposes the on-grid voltage limit as OngridEOD_Voltage, but it's read-only (attempts to update it are ignored). As detailed below, I tried to add it myself and was blocked by the dongle ignoring the update.

The off-grid voltage limit does not appear to be exposed, so I expect that will require a change to the dongle firmware as well.

Home Assistant Version

2025.12.5

Additional Context

I've been unable to get my EG4 LL-S batteries to calibrate even when following the calibration instructions. They enter undervoltage protection mode and shut down while reporting something like 60% SOC and then they show 0% when powered back on, yet they don't bottom calibrate as expected and the same thing happens repeatedly within days. Because of this, I've given up on SOC having any meaning and I've switched discharge control to voltage, which so far has been much more predictable and usable.

I want to automate the on-grid discharge cut-off voltage to help reduce grid usage during on-peak times even when there isn't enough solar production. I tried Peak Shaving Mode and could not get it to work at all, so changing the cut-off value would be my workaround.

In const.py under number, I added this:

"holdbank5": [
    {"name": "On-grid Discharge Cut-off Voltage Limit", "type": "number", "unique_id": "OngridEOD_Voltage", "unit": "V", "min": 40, "max": 56, "mode": "box"},
],

Side note: I used box instead of slider because the sliders are annoying to use and don't normally display their value. I created PR #102 to change all of the sliders to boxes as well as changing some display units from words to symbols.

However, it doesn't work and HA gives this toast message:

Failed to perform the action number/set_value. 'InverterNumber' object has no attribute 'revert_state'

I tried publishing directly to the /update topic just as it's done for the EOD value:

{
  "setting": "OngridEOD_Voltage",
  "value": 50,
  "from": "homeassistant"
}

It did not get a response. I tested EOD to be sure I was doing it right and that did get a success response.

[zakery292]

Ill take a look for you over the next few days i assume you have set the discharge control to Voltage not SOC as HA will whinge about that as well.

[zakery292]

In response to your side note instead of a PR to force users to use boxes and number entry which is prone to HA firing more commands than we want due to HA's update on exit code in the UI it might be prudent to add to the config flow:

Add option for config, sliders or inputs

This gives users the best of both worlds for entity creation. i might have to add a debounce back in to ensure that we get no more updates than 1 per second like we used too but we can put together something in the dev branch and have a go to see how it reacts.

[pilot51]

Yes, discharge control is set to Voltage and I've been changing the cut-off voltage through the EG4 web interface. I can't be consistent by changing it manually, so the ability to automate it in HA would solve my concern.

I created PR #102 before I saw your response. I'm not familiar with that issue. How would I test for it?
Feel free to add the change to the PR since you know more about it.

[zakery292]

It would require changes to the config flow, translations, Various other files.

its currently 00:44 UK time i cant be jumping into this now let alone releasing a update at this time of night no doubt ill break something im exhausted. Its my Birthday today (3rd) so i wont be in my office till the evening time at which point ill jump into this and take a look, the fix will be in the number.py, where the state reversion happens is likely to be a single line change but im not even sure its needed any more id have to double check the switches as they follow similar logic or it might be down to the change from slider to box as the number reversion might not respect the original number from the box due to how HA updates on exit we might not be able to get the previous value in which case the whole thing might need fixing to work another way.

Ill look into it after my celebrations tomorrow when i can if not @rbaugh might be able to take a look i dont know whats on his plate or if he has time he has helped before in the past.

I understand your concern but as this is open source this is freely editable by others not just myself and i would hope that someone else that might have more time spare than me could jump in and take a look failing that ill do it tomorrow after ive had my celebrations and what ever else is in store for me.

[zakery292]

use {"setting":"ACChargeBatCurrent", "value":"460", "from":"HomeAssistant"}
where 460 is make sure thevoltage you want is written 460/461 etc without the decimal place itll change the value you want, it cant be lower than CutVoltForDischg

[pilot51]

I'm confused. ACChargeBatCurrent isn't the discharge cut-off voltage and you're suggesting setting it to a voltage when the name of the setting clearly indicates that the value is for current.

I see ACChargeBatCurrent in holdbank5 with a value of 0 but I don't see CutVoltForDischg anywhere. I tried setting both through holdbank5, neither received a response and ACChargeBatCurrent did not change.

The dongle is on firmware 3.1.78.

[zakery292]

The name is wrong on the parser in the dongle that converts names to register numbers. the register you want to change is ACChargeBatCurrent which when changed will change the voltage register.

ill push a beta update on the dongle tonight to address this setting this ACChargeBatCurrent to 0 wont work as its the voltage register the minimum is 40 which should be sent as 400 as per my previous comment.

sending {"setting":"ACChargeBatCurrent", "value":"460", "from":"HomeAssistant"}
will change CutVoltForDischg as the naming is wrong which is my bad.

[zakery292]

CutVoltForDischg is hold bank 3 i think
dongle version 3.2.286 fixes the naming issue
HA version being bumped to solve the logic issue

[pilot51]

Sorry, I didn't realize I was publishing to the wrong topic.

After further testing (still on 3.1.78), I confirmed setting ACChargeBatCurrent changes the On-Grid Cut-Off Volt setting in the EG4 web UI and it is reflected in holdbank5 by OngridEOD_Voltage while the ACChargeBatCurrent value remains 0.

Updating CutVoltForDischg changes the Off-Grid Cut-Off Volt setting. I checked holdbank3 again and it isn't there, though that is where EOD for On-Grid Cut-Off SOC is.

[pilot51]

I updated to firmware 3.2.286 and HA 3.1.06.

CutVoltForDischg still isn't published in any of the hold banks.

Setting OngridEOD_Voltage directly via MQTT now works, but I'm still unable to set it from the HA entity.
The dongle publishes it as xx (truncating the decimal) and it needs to be sent in update as xxy, but HA can't send it as xxy because it limits the range to 40 - 56 with 0.1 step (xx.y).

BatStopChgVolt and GenChgStartVolt have the same issue, published as xx and expects updates as xxy which HA can't set.

I found that ACChgStartVolt, ACChgEndVolt, ForceDichgEndVolt, and GenChgEndVolt are published and displayed as xxy, but likewise can't be set through HA because update expects xxy and HA has a range that restricts them to xx.y.

I also noticed inconsistencies in those ranges:

• ACChgStartVolt has a range of 38.5 - 52 in HA while EG4 uses 40 - 57
• ACChgEndVolt has a range of 48 - 59 in HA while EG4 uses 42 - 59
• BatStopChgVolt has a range of 40 - 56 in HA while EG4 uses 40 - 59.5
• GenChgStartVolt has a range of 40 - 56 in HA while EG4 uses 40 - 57
• GenChgEndVolt has a range of 50 - 60 in HA while EG4 uses 42 - 59

For now, my workaround is to use MQTT in the automation instead of the entity.

[zakery292]

So RE the not sending correctly ill adjust that, used to do it not so why thats changed.

RE the Ranges lux seems to have different ranges on the docs i have these are set as per the docs i have not sure why EG4 would be increased. will have to look at how i can have conditional ranges

[zakery292]

Fixed in 4.0.0