I am on a boat with a lot of blue boxes, Venus GX, Raspberry pi’s, DIY LFP system with Orion BMS with CAN bus & NMEA2000, CZone and more. I am really motivated to integrate and automate several areas into a more workable and maintainable system. I want to get any feedback on my goals on basic practicality, level of effort needed and reasonable approaches to reach my ends. Here are a few:
Set the desired State of Charge for my batteries with a button or slider - just like you can with a Tesla
Prioritize solar and wind over shore power when conditions are appropriate an d turn on and off my Skylla-i chargers when rules require
write custom alarms from non Victron systems/sources using VRM
Send erroneous alarms made by Victron gear intro the void. (My Skylla-i chargers send a low voltage alarm every time the remote on off is triggered as intended and all support options, dealer, victory and community remain quiet on the matter.).
Make my own web based GUI to get and see the necessary data.
Thanks for any thoughts on this.
Solar priority is embedded into the inverter/charger firmware, configured via veconfigure - there is a blog post on this.
Provided VRM recognises the device and allows you to create widgets for it, then you can create alarms for it. If it is not recognised you will need to use node red for this.
Dashboards are a feature of nodered, visible via VRM and locally.
Thanks, Nick. Unfortunately, the solar priority requires an inverter/charger. I have separate Skyla-i chargers and phoenix inverters. I explain why below. What possibilities are there for achieving solar/wind priority control of my chargers?
I have an aluminum hull subject to galvanic corrosion. I needed a way to both meet the US ABYC standards and not provide an AC ground connection to shor. I use two Skylla-i chargers connected directly to shore power but without bonding the hull to the ground/earth return. All AC loads are then served by inverters. There is no direct pass through of shore power for loads other than the chargers. Isolation transformer won’t meet my needs and the overall topic is quite complex, so probably best to just assume the need for rolling my own solar priority mode is justified.
Thanks for your reply. I think ESS is not intended for use on a boat with all power sources including shore power being intermittent. Please correct me if I’m wrong.
You are correct. While technically it can work, the issue is that on changeover the shore plug can be live momentarily, which is a safety issue, so Victron don’t want it used in mobile applications.
My bad on the inverter/charger, you are correct that priority features do need a multi or quattro.
Desire SOC feature could be achived via ESS/DESS, that’s my point. I have intermittment grid in Ukraine and I’m using it for the purpose of savings + keeping my batteries at desired SOC ( I have schedule of power cuts in advance )
That’s why I suggested it.
But you are right, initially - not created for this specific purpose
Thank you, Andrei. In my case, because of my implementation (where chargers and inverters are separated), I can safely handle ESS. My grid connection only feeds my chargers. There is no AC input to my inverters. There is thus no potential for islanding and leaving my shore power cable hot when disconnected from the grid. However, I am not sure ESS will work for me?
If ESS allows setting a target SOC as an input, how does it control the charger? My Skylla-i chargers support VE-CAN and the GX sees them, but DVCC is not supported. Does ESS provide another control possibility via assistants? The only CAN inputs these chargers accept to my knowledge are on/off and AC input current limit. On off might be good enough but not ideal. I want to control their charge current limit if possible. Maybe I could use Node Red to receive certain inputs and dynamically compute a value for the charger AC input current limit which in turn must limit the DC output current? That assumes I can timely and reliably calibrate the AC input to DC output current of the charger to meet the SOC target. That’s my hope, but as a back up plan, I might use the on/off CAN message or as a brute force option, I could use a relay output to the remote on off cable of the chargers.
I have two inverters. One is a Phoenix 230V/5000VA and the other a 120V Multiplus. Neither have AC inputs. The Phoenix appears to use Multiplus firmware and is identified as a multi in the VenusGX. I think both could be ESS enabled. However the two paralleled Skylla-I chargers probably not? If ESS can be installed in a multi used ans inverter only could it still control other devices like the Skyla-I chargers?
You don’t need ESS to control devices, DVCC will do that for supported devices.
This way at least all the chargers are coordinated, and, if you have a managed battery, will be under BMS control.
Hi Robert,
based on some NodeRed samples I found online I produced this to keep my LiFePos inbetween a specific SOC intervall. It also controls the Intervalls after which I force a complete recharge to balance battery cells and resync shunt and actuall battery SOC.
It solely works by turning my MultiplusCompact from off to load mode using its preconfigered load parameters.
Arne, that’s wonderful. Where/how is the user interface accessed? Webpage on local web server? Are you using DVCC to control the charge range? I am now only able to control my Skylla-i chargers with on/off. I have them set as constant voltage power supplies. The BMS turns them on and off as needed and I control that via a clunky and unpleasant Windows program running on a stick computer over Remote Desktop. I want a little touch screen with something like yours that is running and available for me to access at all times.
Nick, can you please provide any advice on how to control Skylla-i chargers remotely since DVCC is not supported? The remote on/off cable is with the chargers in power supply mode is the only way I have found so far. This not only triggers low voltage VRM alarms every cycle, it means I cannot take advantage of the BMS charge current limit data available on the CAN bus.
The Skylla-i over CAN bus does support on/off and also AC Input Current Limit. I could try to use the on/off that way, but it isn’t much different than what I have already with simple on off cable. I really need control of the current limit.
Is it possible to programmatically control a Skylla-i charger’s output current by providing a CAN Bus message with the value of AC Input Current Limit? If that is possible, I could use Node Red to get the CCL from the BMS and after some calibration, send to the Skylla-i a CAN message to set the Input Current Limit which in turns limits the output current limit. Please let me know if this is a reasonable idea before I start tinkering with a critical operational system.
You can try to use a Skylla-i Control GX device. Link here.
As long as a Skylla-i charger could be controlled by such device, for sure you can set all things it could control: charge current, battery voltage, input current, input current limit.
If you don’t want to buy such device, if you can borrow one, it’s just a matter of sniffing the CAN frames.
Alternatively, you may just want to experiment and use the standard Victron registers for setting things.
Do you see your Skylla-i chargers inside Venus GX?
If yes, you can try to use vreg utility on your GX device to try to read those registers.
If you can read them, then you can try to write them.
For example, for dispatching current settings among chargers, Victron is using register 0x2015 (VE_REG_LINK_CHARGE_CURRENT_LIMIT)
Thanks, Alex. I do have a Skylla-i Control GX panel. Unfortunately, it only provides control support for On/Off and AC Input Current Limit. Those are the only two inputs I can find in any documentation. When I look at the Charger Control node in Node Red and select the Skylla-i, it then shows only the same two functions of “Charger on/off” and “AC Current Limit (AAC)”. Using On/off via CAN rather than the remote on/off cable as I have it now seems possible. Maybe it’s better, but not clear since on/off works. What I want is to control the output current limit. I am hoping I might indirectly use “AC Current Limit (AAC)” for this - a purpose it was not designed to serve.
It’s purpose is to reduce the load on shorepower connections. Sometimes shorepower connections have very long runs of undersized wires that results in significant voltage drops and a resulting increase in current to deliver the same power which results in tripped breakers.
My hope is that I can reduce the AC Input Current so as to indirectly reduce the output current limit. What I do not know is the practicality of this approach. Can this setting be made very frequently? Is there a consistent and linear reduction in the DC output when you reduce the AC input? What about voltage fluctuations? Is there some hysteresis in the setting so it takes awhile to settle out? Are there other variables from say temperature or battery SOC that could have an adverse impact? I’m digging here for any advice from anyone who’s done something similar to save me a bunch of time (or worse).
I see…
I was under the impression that with that rotary knob, you can scroll among those 4 options (charge current, battery voltage, input current and input current limit) and then set them individually.
Now I see that the current and voltage are set by some potentiometers on Skylla-i.
So it may not support control over CAN for those parameters that are hardwired and dependent on those potentiometers.
I am shooting in the dark here, as I don’t have a Skylla-i charger.
Hope you didn’t mind my intrusion on the topic.
LE:
Setting the input current limit for sure will influence the output current if you set it small enough.
As per all other questions, trial and error will definitively bring answers…
Hi Robert,
I am not using DBCC at all.
I installed the Venus OS Large OS on my Cerbo GX and enabled NodeRed in the Cerbos setting under VenusOS Large Features.
