forcing smartsolar float mode from modbusTCP?

Question

question

Les Mulder asked Sep 22, '20

forcing smartsolar float mode from modbusTCP?

Hi all,

I have an off grid system comprising 4 x 250/85 smartsolar MPPTs with 1000AH 48V NiFe battery bank and a Cerbo GX (plus a bunch of other stuff that isn't relevant to this question)

Because my batteries are weird, the MPPTs generally never go into absorption or float mode unless I turn them off for half an hour once the batteries are full (before 10am most days...).

I've written some code using the python pymodbus libraries that successfully reads and writes register 774 on the MPPTs to turn the controllers off when I see 100% charge state and 64.7V on the batteries, then turn them on again half an hour later, but this is crude, crude, crude...

Register 775 (the charge state) is read only, so I can't just change the state to "absorption" or "float".

Does anyone know of any programmatic way that I can give the controllers a kicking and force them into float mode?

thanks in advance,

Les

MPPT SmartSolar Modbus TCP float

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Les Mulder commented · Sep 24, 2020 at 07:34 AM

Bump

No clues anyone???

0 ·

Modifications Space

Node Red Space

Answer 1 · 2021-10-10T17:06:50Z

Mike Dorsett answered · Oct 10, 2021 at 05:06 PM

You would need to write the code to talk directly to the MPPT over the VEdirect connection using Hex protocol. Then you will be able to fully control the MPPT - this register is 0x201 for the state, and 0x2015 for the charge current limit. (Read the dos from Victron for full details. However, the Cerbo GX is going to be using the VE direct interface (?) so you would need to turn on the dynamic current limiting, and use the dBus signals to limit the charge current or voltage set points. For a look at how the dbus signals from the BMS to the Venus OS work, have a look at Louis Van der Walt's serial battery project.

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question