Charge battery with solar during free power period

[DoinitSideways]

I just sent the following to SolaX tech support...

**
Inverter: SolaX X1-VAST-8kW
Serial: 10M0810
Integration: Home Assistant via solax-modbus (Modbus TCP)

Goal: Between 11:00–14:00 daily, electricity is free (zero-cost tariff). We want to fully charge the 28.8kWh battery using both solar input AND grid import simultaneously during this window, then revert to normal self-use after 14:00.

Problem: We have found two approaches, each with a limitation:
Manual Mode → Force Charge — confirms grid charging but turns off solar input (PV drops to 0W)
Self Use Mode + charge timers + Selfuse Nightcharge Upper SOC = 100% — solar continues but no grid charging occurs during daytime (appears to be nighttime-only firmware behaviour)

Available controllable entities on this inverter:

Charger Use Mode options: Self Use Mode, Feedin Priority, Back Up Mode, Manual Mode, PeakShaving, Smart Schedule

Manual Mode Select options: Stop Charge and Discharge, Force Charge, Force Discharge

Modbus Power Control (direct) options: Disabled, Enable Power Control Mode, Enable Electric Quantity Target Control Mode, Enable SOC Target Control Mode, Push Power–Positive/Negative Mode, Push Power Zero Mode, Self-Consume – Charge/Discharge Mode, Self-Consume – Charge Only Mode, Individual Setting – Duration Mode, Individual Setting – Target SOC Mode

Remotecontrol Power Control Mode (mode 8/9) options: Disabled, Mode 8 – PV and BAT control – Duration, Negative Injection Price, Negative Injection and Consumption Price, Export-First Battery Limit, Enabled Grid Control, Enabled No Discharge, Enabled Feedin Priority

Key number controls: Battery Charge Max Current, Selfuse Nightcharge Upper SOC, Backup Nightcharge Upper SOC, Feedin Nightcharge Upper SOC, Remotecontrol Import Limit, Remotecontrol Target SOC, Remotecontrol Timeout, Remotecontrol Autorepeat Duration, Remotecontrol PV Power Limit

Time controls: Charger Start/End Time 1 & 2, Discharger Start/End Time 1 & 2

Question: Which mode or combination of settings would allow the inverter to charge the battery from both grid and solar at the same time during a defined daytime window (11:00–14:00), then automatically revert? Is there a specific Modbus Power Control mode or Remote Control mode designed for this use case?

I hope this is enough information to start looking into a local solution.
**

This was the reply

Thank you for reaching out to us. We recommend using TOU mode: https://kb.solaxpower.com/solution/detail/2c9fa4148ceddee5018e358c915a1736

But it doesn't seem to help me with just using modbus and HA to control it.

Ultimately the goal is to, between 11 and 2, fully charge the battery from the grid but also taking the solar in during that time.

[Pengo429]

My energy plan also has free power between 11am and 2pm. I also get an incentive if I don't import between 6pm and 8pm. I've set up 4 automations to cover the day for my Solax X1 Hybrid Gen4 with 11.6kWh battery.

1. At 11am, 12pm and 1pm, the automation triggers to recalculate how much current needed to reach 100% by 1:30pm, then adjust settings to suit. I control the import so the solar contributes over the period.
2. If 100% capacity before 2pm, adjust settings to keep importing from grid.
3. At 6pm, force a discharge in manual mode.
4. Self use mode, Export first battery, 2pm, 8pm and 2am. (I can't get 'Remotecontrol Autorepeat to work properly, so I just re-trigger)

I was previously using the Solax app with self use TOU, but I couldn't control the rates of charge/discharge automatically.
Give us a yell if you think I can help you further.

[DoinitSideways]

Hey, thanks for sharing this — really useful to see how you've approached it! Our setups sound very similar. I'm also on an X1-VAST with a free window 11am–2pm and an export incentive in the evening.

I love the idea of recalculating the required current at 11am, 12pm and 1pm to hit 100% by 1:30pm — I've done something similar with a helper sensor that calculates the amps needed to fill the battery spread across the 3-hour window, accounting for current SOC.

My question is around how battery_charge_max_current behaves during Force Charge. When you say "I control the import so the solar contributes over the period" — how are you achieving that? In my testing, the register seems to act as a total charge limit (solar + grid combined), so when solar production exceeds the cap, the surplus exports to grid rather than going into the battery. The grid ends up replacing solar rather than complementing it.

What I'd ideally want is solar as the primary charge source, with the grid only topping up if solar drops below my required rate. Is there a separate register for grid-only charge current, or a minimum charge floor that lets solar stack on top freely? Or have you found a way to set the cap dynamically high enough that solar always fits within it while still protecting your circuits?

I'm also cautious about setting it too high — I have pool pumps, A/C and washing machines running simultaneously so Id like to spread the draw over time to lessen the grid draw, which is why I can't just set it to max and let the inverter sort it out. If for some reason i lost grid power unknowingly, id essecntially lose the excess solar as it would likely just get clipped instead of going to battery.

Any insight into how you're handling that balance would be great!

[Pengo429]

Remember, my system is an X1 Hybrid Gen4 so there could be differences in how our inverters run.

Here is my automation for the charging period. I don't know if all settings are needed but since it's working for me, I won't modify it. I hope it will answer your questions.

Grid Charge at 11am - 2pm Automation.yaml

I've also attached a graph of today's charging period. Key:
white - battery SOC
lime - PV
orange yellow - grid import
blue - home use (battery not included)
red - grid export

[DoinitSideways]

Hi!!! Thanks for reaching out, I eventually created 2 automations with the help of Claude and MCP. First force charges from 11:05 to 1:55 at 6kW This fills the battery additional to the solar generation. Second force discharges to grid at 750w. Main reason is I need to ensure that I import 0kWh during that time and I earn a dollar, then if I export 2kwh at 15c/kwh at that time it pretty much cover the daily access charge. Fingers crossed it all works out as I hope. I’ll post a history graph to show how they run. And if it works I’ll dump my automation yaml in here for others looking to do the same. Message ID: ***@***.***>

[Pengo429]

This sounds like Globird's ZeroHero plan. I've got my automations to work, EXCEPT: I keep getting import spikes when the inverter keeps going back to self use mode. Sometimes I miss the $1 because I go over the import limit. Good luck with your effort.

[DoinitSideways]

Oooh, yes it is. I’m staying off there VPP. Waiting for the connection to switch… I’ve set my automation for export to start 5 minutes before and run to 5 minutes after the zero use window. Regards, JB On 18 May 2026, at 1:47 pm, Pengo429 ***@***.***> wrote:  This sounds like Globird's ZeroHero plan. I've got my automations to work, EXCEPT: I keep getting import spikes when the inverter keeps going back to self use mode. Sometimes I miss the $1 because I go over the import limit. Good luck with your effort. — Reply to this email directly, view it on GitHub<#2042 (reply in thread)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AWZM5W34H7QGRCYJ26OCOZT43KBV5AVCNFSM6AAAAACY63CDCKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTMOJVGU3TQNQ>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[Pengo429]

How are you going with your automations? Have you got a working one for the 6pm-8pm no charge period?

[DoinitSideways]

alias: Solax Force Discharge 17:55-21:05 (Cashback Period)
description: >-
Daily Force Discharge during cashback/export tariff window (18:00-21:00 AEST).
Exports 750W to grid via Manual Mode + export_control_user_limit. Restores
Self Use + 5000W limit at stop.
triggers:

• at: "17:55:00"
  id: start
  trigger: time
• at: "21:05:00"
  id: stop
  trigger: time
• entity_id: sensor.solax_inverter_solax_x1_vast_battery_capacity
  below: 66
  id: stop
  trigger: numeric_state
• event: start
  id: ha_start
  trigger: homeassistant
  actions:
• choose:
  • conditions:
    • condition: trigger
      id: start
      sequence:
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_lock_state
      data:
      option: Unlocked - Advanced
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: >-
      number.solax_inverter_solax_x1_vast_inverter_export_control_user_limit
      data:
      value: "900"
      action: number.set_value
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_charger_use_mode
      data:
      option: Manual Mode
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_manual_mode_select
      data:
      option: Force Discharge
      action: select.select_option
  • conditions:
    • condition: trigger
      id: stop
      sequence:
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_manual_mode_select
      data:
      option: Stop Charge and Discharge
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_charger_use_mode
      data:
      option: Self Use Mode
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: >-
      number.solax_inverter_solax_x1_vast_inverter_export_control_user_limit
      data:
      value: 5000
      action: number.set_value
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_lock_state
      data:
      option: Locked
      action: select.select_option
  • conditions:
    • condition: trigger
      id: ha_start
    • condition: time
      after: "21:05:00"
      before: "17:55:00"
      sequence:
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_manual_mode_select
      data:
      option: Stop Charge and Discharge
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_charger_use_mode
      data:
      option: Self Use Mode
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: >-
      number.solax_inverter_solax_x1_vast_inverter_export_control_user_limit
      data:
      value: 5000
      action: number.set_value
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_lock_state
      data:
      option: Locked
      action: select.select_option
  • conditions:
    • condition: trigger
      id: ha_start
    • condition: time
      after: "17:55:00"
      before: "21:05:00"
      sequence:
    • delay:
      seconds: 30
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_lock_state
      data:
      option: Unlocked - Advanced
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: >-
      number.solax_inverter_solax_x1_vast_inverter_export_control_user_limit
      data:
      value: 750
      action: number.set_value
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_charger_use_mode
      data:
      option: Manual Mode
      action: select.select_option
    • delay:
      seconds: 10
    • target:
      entity_id: select.solax_inverter_solax_x1_vast_inverter_manual_mode_select
      data:
      option: Force Discharge
      action: select.select_option
      mode: single

[Pengo429]

Looks interesting. Could you upload the yaml file?

[DoinitSideways]

alias Solax Force Charge 1105-1355.yaml

[Pengo429]

You uploaded the 'charge' yaml when I asked for the 'discharge' yaml, as written in your previous reply.

[DoinitSideways]

Hi! Yeah, I’ve got it working pretty well so far I believe… the 3 hour charge period and the 3 discharge period are working well. Regards, JB On 2 Jun 2026, at 6:48 pm, Pengo429 ***@***.***> wrote:  How are you going with your automations? Have you got a working one for the 6pm-8pm no charge period? — Reply to this email directly, view it on GitHub<#2042?email_source=notifications&email_token=AWZM5W4QJJW5FIMBH4LL2PL452IE3A5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNZRGQ4DSMJQUZZGKYLTN5XKMYLVORUG64VFMV3GK3TUVRTG633UMVZF6Y3MNFRWW#discussioncomment-17148910>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AWZM5W57M2KJ22FMMDT5C73452IE3AVCNFSM6AAAAACY63CDCKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTOMJUHA4TCMA>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[DoinitSideways]

Ahhh… sorry!! I was also doing a PowerPoint presentation with photos of the dog for my kiddo… 🫣 Regards, JB On 4 Jun 2026, at 9:19 pm, Pengo429 ***@***.***> wrote:  You uploaded the 'charge' yaml when I asked for the 'discharge' yaml, as written in your previous reply. — Reply to this email directly, view it on GitHub<#2042?email_source=notifications&email_token=AWZM5W2OI36WVK74VMKSK6D46FLKRA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNZRG44TQNJWUZZGKYLTN5XKMYLVORUG64VFMV3GK3TUVRTG633UMVZF6Y3MNFRWW#discussioncomment-17179856>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AWZM5W27NAVHWG7T34C2YIL46FLKRAVCNFSM6AAAAACY63CDCKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTOMJXHE4DKNQ>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[Pengo429]

Are you going to upload your discharge yaml file??

[DoinitSideways]

[Pengo429]

I gave you 3 days. You would of had a long weekend if you were in NSW. Anyway, it hasn't formatted properly. When you can, upload it like the charge yaml file.

[DoinitSideways]

solax_force_discharge_automation.yaml