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fbo avatar image
fbo asked

Turning off MPPTs intentionally

Dear Victronians,

my setup is a GX, some Multiplus II and some Smartsolar MPPTs using ESS which avoids to feed power into the grid. I'd like to turn off the MPPTs from time to time to implement an upper SOC limit. This document

https://raw.githubusercontent.com/victronenergy/dbus_modbustcp/master/CCGX-Modbus-TCP-register-list.xlsx

shows a writable modbus variable ( "/Mode" , 774) which affects the MPPTs in the way I want. But: Is it safe to write to it often (is the state stored in a flash)?

Optimally, I'd like to set the MPPTs maximum charge current/power but there seems to be no way to do so. Is this correct?

Thank you for any advise.

Frank

ESSMPPT SmartSolar
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andrii-podanenko avatar image
andrii-podanenko answered ·

It is safe

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fbo avatar image fbo commented ·

Hi Andrii,

thank you very much. Do you know of a source, where to find information like that? I'd love to make a map "modbus address" to "flash or not".

Best regards

Frank

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alexander-uhde avatar image
alexander-uhde answered ·

Hi Frank,

wouldn't it be better to use "max charge current" for that?
I have implemented a node-red function to restrict SOC to certain limits from time to time.

Using modbus this should be register 2705 for an ESS.
I guess this should be safe to be written often, since it seems to be used by ESS regularly when nearing certain SOC limits.


Regards

Alex


Edit:

"Optimally, I'd like to set the MPPTs maximum charge current/power"

Sorry, I did not read this one carefully enough the first time.

"max charge current" exactly does this one.

You can set it in 1A steps from zero to whatever maximum is possible.
This value can be overwritten by your BMS, if your desired value is higher than possible.

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fbo avatar image fbo commented ·

Hi Alexander,

2705 seems to be a Victron setting which means, it's defined in /data/conf/settings.xml and updated there. Unfortunately, my use case requires frequent writes (e.g. once every 5 minutes) which is a bit much for my GX's flash storage

Best regards

Frank

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