question

Jack Young avatar image
Jack Young asked

Multi RS solar with Fogstar battery and Cerbo gx

I’m looking to build a system with solar and battery, looking at using the multi rs solar, and Fogstar 15.2kw LifePO battery, which requires a Cerbo GX to communicate with the inverter.

The Fogstar and the multi rs solar use VE.Can and BMS-Can to communicate with the gx, but I noticed the manual for the gx states in section 4.5, that VE.Can and BMS-Can cannot be combined on the same bus - does this mean I cannot use the Cerbo GX for this combination of products?

cerbo gxMulti RS
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2 Answers
Alexandra avatar image
Alexandra answered ·

@Marley2010

Use the cerbo GX not the cerbo s

You can set different speeds on each port on the full cerbo so no issues there.

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Alex Pescaru avatar image
Alex Pescaru answered ·

Hi @Marley2010

It's all about communication speed.

Cerbo GX mark 1 has two CAN ports.

One dedicated (and marked so) for BMS communication that is fixed at 500kb speed and another that is more versatile and also can be configured as BMS communication.

Multi RS is connected on this versatile CAN port and is communicating at 250kb speed with so called VE.CAN protocol. Therefore it can't be used on the same time, on the same bus, with a BMS.

Alex

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Jack Young avatar image Jack Young commented ·
Ah ok, so if I understand, each of the two can ports on the gx are classed as seperate buses?
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Alexandra avatar image Alexandra ♦ Jack Young commented ·
@Jack Young


Yes.
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Jack Young avatar image Jack Young Alexandra ♦ commented ·
Thank you!
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Jack Young avatar image Jack Young Alexandra ♦ commented ·
Just so I’m clear, does this mean I am fine to connect via BMS can to my battery and and VE can to my inverter using the Cerbo gx mk1 at the same time (but on different ports)?
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Alexandra avatar image Alexandra ♦ Jack Young commented ·
@Jack Young

I have a 500kbit/s battery connect to the bms can and a multi rs (250kbit/s) connected to the ve-can on the full Cerbo - it works, so yes it is possible

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Jack Young avatar image Jack Young Alexandra ♦ commented ·

brill, do you have the mk1 or mk2 cerbo?

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Alexandra avatar image Alexandra ♦ Jack Young commented ·

I have both the first gen and second gen. Haven't noticed a difference in function.

Obviously there is in spec and a few ease of use items.

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