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andreas-siebenmorgen avatar image
andreas-siebenmorgen asked

EV Charging Station: Configure using Modbus

I am getting nuts telling my Victron EV charging station to charge my car in off grid mode + Auto mode.

I've read many post and tried many things, but it does not work.

During my search I read something about Modbus, which I am totally unconfident with.

I've assumed that I don't need to be a "programmer" to setup my EVCS doing things I want to.

FYI:

- Cerbo + Multiplus + EVCS etc. with latest firmware

- Manual Mode is working fine

- Installed PV peak Power 4800W (during actual weather conditions about 3500W peak)

One of my unasnswered questions:

- What are the ultimate conditions for my EVCS to start charging in Auto mode?

I've read so may times "starts when there is enough PV excess power".

But: What is "enough excess power", where and how is it defined?


I need about 1840 w when set to 8 amps for charging my car, so getting more than 3000 w from the roof must be "enough excess power", right or wrong?

But it does not start.

Also there is no setup in EVCS where I can set a power value which has to be reached before charging starts.

BUT:

It look like there is a value within the Modbus table on the EVCS which maybe could be what I am searching for.

1682166940369.png

Can anybody PLEASE tell me, if I am on the right track, and if yes, how to check and modify this value.

BTW: I am totally new to this Modbus thing!!! So I need a manual for dummys ;-)

ev charging station
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1 Answer
Lucian Popescu (Victron Energy Staff) avatar image
Lucian Popescu (Victron Energy Staff) answered ·

It should work without modifying any of the modbus parameters. Can you share a video from the main webpage of the EVCS while not charging in automatic mode?


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andreas-siebenmorgen avatar image andreas-siebenmorgen commented ·


Video attached…

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Lucian Popescu (Victron Energy Staff) avatar image Lucian Popescu (Victron Energy Staff) ♦♦ andreas-siebenmorgen commented ·
Your system consumes from the grid, that's the reason. Can you modify the grid set point to a lower value? EVCS threshold for that parameter is 25W, you can increase it if you want, Modbus TCP address 5084
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andreas-siebenmorgen avatar image andreas-siebenmorgen Lucian Popescu (Victron Energy Staff) ♦♦ commented ·

My Multiplus isn’t connected to the grid. There is just an EM24 connected for monitoring grid consumption for devices like my stove which is still grid tied.

Grid and off grid devices are fully separate.

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andreas-siebenmorgen avatar image andreas-siebenmorgen Lucian Popescu (Victron Energy Staff) ♦♦ commented ·

Hi Lucian,

it looks like Modbus address 5084 is the solution for my EVCS problem with auto mode, even with my "special" configuration with two devices daisychained. I will do some more testing, but for now it looks promising.


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alfredsteinki avatar image alfredsteinki Lucian Popescu (Victron Energy Staff) ♦♦ commented ·
Hi Lucian,

I only know the modbus TCP registerlist 2.90. But there is no adress 5084. It ends at adress 4602. Can you tell me where I can find another list with the adress 5084?



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