I found out I can automate my 5,12kWh house battery through local-only RS485 connection, and directly setting registers using ModbusTCP from Home Assistant. I then drafted an automation with hysteresis and damping that tries to aim for Net-Zero export/import (pv surplus/grid). It appears to work!

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isoprophlex 13 hours ago | parent | next [-]

What brand/make of battery is that? I'm tentatively interested in home battery storage, but definitely not interested in shit that requires an app, an internet connection, and shitty saas spyware...

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Helmut10001 8 hours ago | parent [-]

MARSTEK VENUS E 5.12kWh. Got it in August 25 for 1050,00 EUR. It is awesome how open it is designed, I was able to activate and automate it without adding it to my local network (wifi) or using the Marstek App even once. I wrote a blog post here [1].

[1]: https://du.nkel.dev/blog/2026-01-11_marstek-battery-homeassi...

	▲	isoprophlex an hour ago \| parent [-]
		5 kWh for 1k€! Wow! Thanks for sharing Edit: and thanks for the writeup. This is exactly what I was looking for

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Gibbon1 14 hours ago | parent | prev [-]

The deranged thing about RS485 and modbus is it's old cheap and just works.