NOde-red, battery time to go

Modifications Node-RED
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1

Hello,
I assume, that with node-red is possible to get battery “time to go”. Am I right?
If so, could you please help me with that. I do not have any node-red skils, so Im like a monkey, who try to play piano… pretty much hopeless.

I have following components in use:
Multiplus I, not II, 48V, 230V/5000VA
3x MPPT 150/35
Venus GX
Pylontech battery 15.5kWh
I do NOT have any smart shunt
Im 98% off grid, but I also have grid connection.

If there is any kind person, who have done this already, could you share it with me, please.
(Would be really nice to have a node-red slider also, so I could adjust DOD of the battery)
I have looked from internet/youtube, but I could´t find any flow, which would work with my system…or I just dont know how to make it work, Im hopeless..
Thanks !!

2

There’s a time to go in com.victronenergy.battery dbus path:

dbus · victronenergy/venus Wiki · GitHub

I’ve not checked myself but I imagine that’s where the time to go indicator used by VRM comes from. In other words I’d guess the battery node in node red

IN regards to the slider is the one in VRM app not sufficient for you? Or are you looking to have a cloudless setup?

If you give some more detail about what you’re looking to have made I’m happy to lend a hand

3

Hi Matt,
Thanks for your reply and support. I have tested that dbus bath, but it doesnt work. I guess, if I would have a smart shunt, it would work, but I dont have a shunt. Without a shunt, I get payload “null”.

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If I select custom input node, there I can see Pylontech battery, but under Pylontech battery measurements, there is no “time to go” option.
So I was thinking, that only option might be to do with node-red some programming.. Battery total capacity - min SOC% - consumption + MPPT PV production - 10% of losses…and so on.. and try to get calculated “Battery time to go time”. That slider that I mentioned, it would be for adjusting min SOC, so “Battery time to go time” would change depending on what is the min SOC level.
Thanks again for your support.

4

Hi @KimmoPaukku

I’m less familiar with pylontech however out of curiosity what have you selected as your battery monitor within venus os/gx device. I thought the battery dbus would be populated with whatever device you had selected as your battery monitor in settings->system setup → battery monitor.

5

Hi Matt,
I have selected Pylontech as a battery monitor. I can get out all other information regarding my pattery, exept “time to go”.

6

It seems to be something that is peculiar to Victrin kit.

With time to go, you will have to add a function node or something that calculates it for you.

7

Hi LX,
Thanks for your reply. If you read my first message, you will see, that I have no any skills with node-red, Im pretty much hopeless. :slight_smile: Thats why Im asking, if some really frendly person could help me out. Im sure, if I will drag 1 or 10 function nodes to the “workspace”, they are not going to solve my issue, without “telling them” what they should do. And on that point, Im getting lost, as I told, Im hopeless with node-red :wink: :wink: :wink:

8

Lets start with how would you work it out? Programming it is the end thing. Knowing how to work it out is the beginning of the problem.

9

I did try checking github to see how it’s calculated on victron devices. ANyone know where that would be, i thought maybe systemcalcs but i could spot it.

10

Hi LX,
Thanks again for your reply. Just a would like to see simple value for “battery time to go”. I have a Pylontech battery bank of 15.5kWh, and I usually keep min SOC level on 20%. Of course would be super nice to have a simple sider on dashboard, so I could adjust of min SOC level, but that would be a nice extra feature. Im 98% of grid, but I have also grid connection, just in case for rainy days. :slight_smile:
Other equipment I do have are: Multiplus 5000VA/230V/48V, 3xMPPT150/35, venus GX

11

…and I mean, time to go till 20%, not to empty, unless I change the min SOC level to 10% or 5%. :), but that I never do.

12

Only thing, what I have been able to do so far is some kind of node-red dashboard, but thats all. And that toke about 2 months of study and do it :wink:

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So if I study maybe 6 or 9 months more, maybe Im able to get that “time to go” as well :wink: :wink: :wink:

13

So you have built the entire dashboard by copying code?
If you have reached that far, then you should be able to build or modify one of those.
what i am saying is what you are asking for is not that simple. Especially when is come to integrating i to what you have already.

Fairly certain you are a logical person and can work out the math.

14

Hi LX,
Thanks for your reply. This dashboard was difficult enough for me. A lot of studing and of course, copy and paste from yhe internet, and then try…try…and try again :slight_smile: But thats the problem, I dont know, how to do the code and all the math… :wink:

15

@KimmoPaukku

Ok one to try… Lets tackle one of your requests at a time. :wink:

We tried writing one with nodes found commonly on systems so transfer is less of an issue
You will need to edit battery capacity and it counts time to go to your min soc set in ess.

You will need to edit the battery capacity in AH in the function node

Edited {Flow removed due to copy oaste errors}

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Hi LX,
Thank you for your help. :slight_smile: When I try to import, I will get this error mensage..

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17

Added at text file

18

Maybe my fingers added something in… :face_with_peeking_eye:

19

Maybe… :joy:

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Time to Go.txt (4.6 KB)