Use battery as a buffer even during charging period

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Bobinho
Posts: 4
Joined: Mon Nov 13, 2023 1:48 pm

Hello,

so far I noticed behaviour during charging window:
- if Force charge/Charge from grid is enabled and there is not enough sun to reach Max charging current, inverter will draw power from the grid to charge up to Max SoC
- if Max SoC is reached and still there is some sun, it always charges up to 100% (not configurable)
But what concerns me is that:
- even if battery is 100% and Max SoC is <100%, for example 90%, and there is not enough sun, lacking load power will be drawn from grid - won't be covered from battery

In other words, as
- grid can charge up to Max SoC and sun to 100%
I would expect it to discharge in inversion, so that
- above Max SoC battery may be discharged

Therefore battery would be a buffer against the clouds.

Do I misinterpret or have misconfiguration?
18x 375Wp (6,75kWp)
H3-8.0-E (8kW)
3x Mira HV25 (7,37kWh)
Home Assistant
Dave Foster
Posts: 1328
Joined: Thu Oct 13, 2022 7:21 pm

Bobinho wrote: Mon Mar 11, 2024 2:31 pm In other words, as
- grid can charge up to Max SoC and sun to 100%
I would expect it to discharge in inversion, so that
- above Max SoC battery may be discharged
Do I misinterpret or have misconfiguration?
The first part is correct, Max SoC is the maximum the battery is allowed to go to when charging from grid, however solar generation ignores this and will top it up to 100%.

The second part is not, Max SoC only affects the grid charge function.

Min SoC on Grid does avoid the battery being discharged should the battery power fall to this % setting.

The battery will always be used to fill the gap of solar unless you have charge period set and grid charge switch set off (which tells it not to discharge between that time period), or you use the work mode ‘Backup’ where the battery will not be used to power the loads at all (but it will allow solar to charge it).
Bobinho
Posts: 4
Joined: Mon Nov 13, 2023 1:48 pm

The battery will always be used to fill the gap of solar unless you have charge period set and grid charge switch set off
I have charge period set and grid charge on.

I feel that allowing battery to, as You nicely phrased, "fill the gap" as long as SoC stays above Max SoC even during charge period would be a way to improve energy cost efficiency during these - why to import if we have more energy stored (becuase it was sunny) than we planned to have even during dark day (for which plan we set Max SoC)?

Is there a way to raise Request For Change for firmware so professionals can also think about this?
18x 375Wp (6,75kWp)
H3-8.0-E (8kW)
3x Mira HV25 (7,37kWh)
Home Assistant
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