Feature request: Battery charging ramp down power

[anton4]

Describe the bug
Currently EMHASS does not take into account that battery BMS typically ramp down charging power after 90% of SoC during charging.
For example - battery max charging power is 15kW and it's capacity is 30kWh.
EMHASS forecasts that it takes 2 hours to fully charge the battery from 0-100%, but in reality it takes little bit longer as when battery reaches 90% (27kWh), BMS ramps the power down 2x (15kW -> 7.5kW).
That means that it will take 1hr48min to reach 0-90% at 15kW power and 24 minutes to go from 90-100% at 7.5kW.
In total that's 2 hours and 12 minutes to full charge a 30kWh battery from 0-100% instead of 2 hours.

Expected behavior
EMHASS takes battery ramp down into account and it can be a adjusted as a parameters.
I think we need at least 2 parameters -

• battery soc when ramp down will start eg. 90%
• ramp down power eg. 7500W

[tbrasser]

You mean constant current to constant voltage charging mode?

[anton4]

No, in this case it's not important how BMS does it.
I am saying that EMHASS does not take battery ramp down into account at all.

[tbrasser]

CC/CV charging is determined by inverter/charge-controller, not bms

[purcell-lab]

You can set the power max charge rate as a runtime parameter.

So you could workaround this by checking the SOC and when SOC is less than 90% set full max charge rate and when SOC is greater than 90% you could set the reduced max charge rate.

[martinarva]

You can set the power max charge rate as a runtime parameter.

So you could workaround this by checking the SOC and when SOC is less than 90% set full max charge rate and when SOC is greater than 90% you could set the reduced max charge rate.

But this will mess up the whole forecast, because then emhass thinks that the max charge rate will be until the end of prediction horizon.