so long story short - on my RV I switched to a Quattro 24/8000/200-2x100 and ended up with minimum current limit @10A. A lot of camping sites are still offering only 4A or 6A here so I’m trying to see if I can find alternatives on how to just charge batteries.
To make it clear I don’t need shore to run my loads as I have 2Kwp of Solar and 1200ah of batteries. I would still be quite happy to just charge @4A as I have hours during the day when I’m not really consuming such.
Is there any way so I can achieve such automatically? I’m good with any proposal, using modbus, signalk, node-red whatever?
As of now the only thing I can come up with is using a shelly (or any smart relay) on the shore connection so that I can at least disconnect (remotely) when going over the maximum current set.
Any ideas? personally this lead me to think it would have been better to have a dedicated charger and a separate inverter.
@guystewart apologies for calling you directly but just reading some inputs on other threads for similar ask - do you have ideas for my use case? thanks
the problem I see with the proposal is that I don’t think a small charger can address the need. For 4A/6A charging (but also for lack of bigger space at this point) I would look at a Smart IP43 Charger (that given the VE.Direct port would be controllable by the Cerbo). However as far as I remember I don’t think you can set a charging current on it, you can only monitor its state
ahhh I see the logic ok - well it’s better than nothing
one more questione please as I have lithium (victron) batteries and not sure how the system will behave at this point if I switch off charger of the quattro and leave in inverter only. Today I’m on BMS v1 but I’m planning to upgrade to BMS v2 and will need to enable DVCC: just need to think about if disabling the quattro charger might inhibit charging from Solar MPPT (victron as well)?
according to specs the 24v version charge max at 25A, so 600w or 2.6A @230v … which is better than nothing but very very low considering that the majority of camps with low amp electricity is probably 6A rather 4A.
You could turn off PowerAssist in the inverter if your 8kVA inverter is all the power you would ever need. But, if you sometimes want PowerAssist, then you could build a flow in NodeRed that will allow you to turn on/off PowerAssist w/o having to use VEconfigure or VictronConnect every time you want to turn PowerAssist on/off. I’ve been meaning to do this in my camper but just haven’t gotten around to it yet. But, I did verify it’s possible with NodeRed
ah that’s the first thing i implemented in my management app (home assistant via modbus) and I can switch it on and off in a moment.
The problem is that, based on my understanding of the situation, once it’s disabled you wont be able to have any load above 6A (in example). I haven’t yet tried but based on what I read any load above 6A will end in a overload ? do you have any experience to confirm?
### Without PowerAssist
What would happen in this exact scenario *without* PowerAssist? You would have to disconnect from the input source and go back to operating off the inverter only. If you feed the inverter with, say, 3000 watts but you need 4,000 watts, well, you have to disconnect from the source, the generator, or the shore power connection. Your other option is to kill all the loads, such as the air conditioner, and charge those batteries. Without power assistance, you may also have to go into your charger settings and reduce the charge current so you're not overloading your small input source.
In a system where you don’t have the ability to supply over twice the inverter size, you really can't charge the batteries and run the loads at the same time. You would end up doing things like backing off the charging current. **PowerAssist is what allows you to bring in a smaller or right-sized energy source - or plug in where no one has plugged in before successfully - while maintaining total power output.**
I understand that I could use the shore until my AC load won’t exceed its capabilities (let’s say 6A in my above example). If that happens to avoid tripping the breaker I will have to disconnect the loads.
@stefano I think your understanding is correct. I wasn’t 100% certain so I didn’t respond to your question on Feb 16th. The guys at Intelligent Controls know their stuff so I accept their explanation without reservation. In your scenario, I would leave PowerAssist turned on and use a separate battery charger. You could connect it to AC2-Out so that it’s only powered by shore power (never inverter) and would be subject to the AC input current limit. This way you wouldn’t need to run a separate cord to the camp ground pedestal.
I have a similar situation in my camper. I have a Victron 12/1200 inverter in the back of my truck that I want to use to charge batteries in my camping trailer while I’m traveling. But, the 24/5000 inverter has a minimum AC current input limit of 10.9A at 120V. That exceeds the continuous output rating of my 12/1200 in the truck. So, I either need to disable PowerAssist when traveling and re-enable it when I set up camp if I have shore power OR install a separate battery charger in the trailer to be powered from my 12/1200 in the truck when traveling. The easiest approach would be the separate battery charger, but the more nerdy approach would be to use Node-Red to turn PowerAssist on/off from a dashboard. We’ll see which one I pick based on how much “free” time I have
@OGPS Thanks a lot for confirming my thoughts - having a separate charger is not an option unfortunately as I would need a Skylla and I don’t have space left for it.
I had this thought in trying to address somehow the case without any equipment and just in software:
suppose max input current need to be 6A
run an automation that constantly check current draw (in my case I will use HA rather than node-red)
if output loads are above 6A I disable my quattro charger and stay in invert only.
as soon as my load run below 6A I disable power assist, lower input current to 6A and enable charger.
If current draws goes down, then I don’t see issues. If the current draw increase most probably I won’t have enough time to increase input current to support such without having my quattro going into overload: do you know if that’s immediate?
This topic is very good! Based on what was discussed, presented and suggested here and in another topic here in the community about the same subject, I was able to satisfactorily solve the problem I was having! I am in a place that offers electricity with 4A circuit breakers, and the minimum input current limit value that my Multiplus accepts is 6A.
Below I make some comments about what was discussed here, after having read everything several times until I was able to assimilate and understand everything, and at the end I share the solution I implemented.
This is fundamental to the problem, and it is something that is not explained clearly and explicitly in the Multiplus manual. I don’t think it was explained here in this topic either, but it was said in the other topic on the same subject, that by disabling PowerAssist it becomes possible to configure lower input current limit values, and that the configured limit will be used in PowerControl.
Exactly.
Yes, the inverter’s capacity is not affected, but the inverter will not be turned on, the AC input will be supplying the load, and with PowerAssist turned off, when the AC load current exceeds the input current limit, the AC input current will also exceed the limit!
No! With PowerAssist turned off, the Multiplus will only be able to keep the current at the AC input below the input current limit while the AC load is below this limit. It does this by controlling the battery charging current. As the AC load increases, it will reduce the battery charging current (PowerControl function) to keep the AC input current below the limit, until the battery charging current is zero. If the AC load current continues to increase, it would keep the AC input current below the limit by turning on PowerAssist, that is, using the inverter to supply the current that exceeds the input current limit. But since Power Assist is turned off, it cannot limit the current drawn at the AC input, and it will follow the load current, until it trips the circuit breaker of the circuit to which the AC input is connected!
Perfect
I was trying to do exactly the same thing! Using an inverter that is actually half the size of yours, 600VA, to charge the battery in the trailer using the car’s alternator. But I had two problems when I tried, first I couldn’t set an input current limit lower than 6A (I needed to be able to set it to less than 3A), and then the 600VA inverter would go into overload protection mode. The second problem I believe was caused by the BoostFactor, which can make the Multiplus inject current for a few moments into the AC input, which I believe my 600VA inverter couldn’t tolerate and that’s why it failed.
Disabling PowerAssist when you are traveling can solve the problem, by allowing you to set a lower current limit value for the AC input, but remember that the limit you will set is not the 1200VA of your inverter, the limit must be what your car’s alternator can supply, which can be less than 1200VA! And then you also need to consider that without PowerAssist turned on, the load limit you set to pull from your alternator is also the AC load limit that you will be able to have connected to the trailer, because there will be no control over the current limit drawn from the alternator if your AC load on the trailer increases. Maybe this is not a problem for you, if you do not need any high AC load connected during the trip (but you will always need to be very careful not to forget something connected). But for me it would be a problem, because I need to leave the trailer’s air conditioning on during trips. And if your AC load on the trailer is never greater than the capacity of the AC input circuit you are connected to when stopped, you do not even need it To reactivate PowerAssist, you can leave it turned off. However, to solve the problem in a much more robust way, without having to worry about the possibility that your AC load may eventually be greater than the capacity of your alternator or the capacity of the AC circuit to which you are connected when stopped, you can configure the solution proposed by Stefano below, using Node-Red, or the simplification of this proposal, using the Multiplus assistants (as I will present in detail below), so that the AC input is disconnected when your AC load exceeds a certain power limit (which may be the capacity limit of your alternator). If this situation is infrequent and does not last long, you can leave it configured like this always, without having to change the settings that need to be made by VE Configure, and the result will be satisfactory. You can still easily change the current limit of the AC input to be able to use all the available power to charge the batteries, charging that will occur whenever your AC load is not above the limit configured in Node-Red or in the Multiplus Assistants to disconnect the AC input. I think that with these solution possibilities, especially the solution using Multiplus assistants makes it very easy to find a good solution and it becomes too complicated and unnecessary to have a second charger in the trailer just to be used to charge the battery using the car’s alternator.
Great idea, Stefano! Using your idea, I was able to implement a solution to the problem using Multiplus Assistants! I’ve already set it up and am using it, and it’s working very well!
In my case I used the Multiplus Assistants (what is HA?). In the Multiplus assistant what is monitored is not exactly the AC load current, but the power in Watts being consumed by the AC load, but it serves the same purpose.
In this case, through the Multiplus Assistant, it is placed in inverter-only mode, ignoring the AC input.
You don’t need to keep enabling and disabling Power Assist. You can always leave it disabled, because you will never use it. When the AC load is above the limit (6A, in your case), if you are going to put it in inverter-only mode, Power Assist will not be activated! Power Assist works by adding power produced by the inverter to the power available at the AC input. If you are going to be in inverter-only mode, all the power for the load will be produced by the inverter; there is no Power Assist in this situation! Likewise, you do not need to keep changing the AC input current limit! The AC input current limit is a parameter that will not be used when the AC input is not being used, and it will not be used when you are in inverter-only mode! In this mode, 0 amps of the AC input will be used; there is no need to have a limit configured! So you can always leave the AC input limit at the value you need, 6A in your case. Since it is not necessary to turn Power Assist on and off, nor to change the AC input current limit, and since it is possible to force Multiplus into inverter-only mode, ignoring the AC input, it is possible to implement this solution using Multiplus Assistants, there is no need to use Node-Red!
The problem of increased AC load is not for the Multiplus. You do not need to have set an AC input current limit for the Multiplus to support the increased AC load. The problem of increased AC load is for the circuit to which you are connected at the AC input, the AC input current limit is there to protect this circuit from overload, not to protect the Multiplus! And you will be protecting this AC input circuit by putting the Multiplus in inverter-only mode (ignoring the AC input), not by increasing the AC input current limit! In the Multiplus Assistant I set how long after the AC load exceeds the limit I want it to take for the AC input to be disconnected (ignored). I set it to 0 seconds. I have been testing it since yesterday and it is working very well, I can connect a very high load (like the Air Fryer) and the AC input is disconnected without the circuit breaker of the circuit to which I am connected at the AC input tripping. Below are the Assistants I created to implement this solution (I set the limit to 880W because in my case the circuit breaker for the AC input I am connected to is 4A, and the voltage is 220V).
With these assistants and with PowerAssist disabled, I can set a current limit on the AC input as small as necessary (without being limited by the minimum value allowed by Multiplus when Power Assist is enabled), taking advantage of the maximum possible power to charge the battery while the AC load is below the established limit, and disconnecting from the AC input when it is above the established limit, so as not to trip the circuit breaker in the AC input circuit, or not overload the car’s alternator, for example.
And if it is not very frequent or long lasting that the AC load is above the configured limit, I can always leave it like this, the only downside will be in those sporadic and short moments when the AC load is above the configured power limit, moments in which the Multiplus will be disconnected from the AC input. It will still be possible and easy to modify the AC input current limit to be able to take advantage of the maximum power available for charging the battery, power that will be used during the entire time that the AC load is below the power limit configured in the Assistants.
Everything we’ve formulated here in this exchange of ideas could be included in some Victron document, because I think this possible solution is very useful for many people! I believe that this limitation of the capacity of the outlets available in campsites is very common for users of electrical systems in RVs. In the part of the Multiplus manual where it says the minimum current limit values of the AC input, they could explain better that these limits only exist when PowerAssist is enabled, but that it is possible to configure lower values to be used by Power Control if Power Assist is disabled! And then they could include a link to a short document that explains this way of getting around this Power Assist limitation using this programming in the Assistants!
I hope that in the meantime, all of my comments here will help anyone who is having this problem and can find this conversation!
The solution I proposed above is great if it is to always keep the AC input current limit at the same value (and this value being lower than the minimum configurable value when Power Assist is enabled). But it is an impractical solution if you need to change the configured limit, because you will need to do it through VE Configure, enabling or disabling PowerAssist, inserting or removing the assistants and changing the AC load value in the assistants that causes the AC input to be ignored. A better, much more practical solution would be to automate all of this through Node Red, configuring everything according to the current limit set by the console. I tried to do this, but I encountered a difficulty: when Power Assist is enabled, and a current limit value is entered through the console that is lower than the minimum acceptable value when Power Assist is enabled, the value entered is automatically replaced by the minimum value, and I cannot get the value that was entered in Node Red to be able to disable Power Assist. I talked about this in this other post, let’s see if a solution appears for this.
Hi Valdson and thanks for joining the conversation!!!
HA is Home Assistant (https://www.home-assistant.io) an open source home automation system that can interact with Victron in many ways, in my case via modbus
You cn build very quickly (much easier and directly from your phone) new automation or disable/enable/edit existing one. It’s both UI orientend and code oriented (via yaml through its editor).
The reason I chosed it is exaclty in the limitation you described because this way I can enable/disable Power assist on the fly (with an automation or even with a switch). The only reason I would still enable Power Assist (even if not needed) is to make sure I don’t leave it disabled if CAMP MODE (how I called the above described situation) is not needed anymore.
See how I have both Power assist enabled on the left (it’s both an icon and a switch, meaning that not only I know if it’s enabled or not but also can change its state) and Camp Mode on the bottom. Camp Mode it’s a virtual switch which will enable two automations:
This is how the visual automation editor is presented
I’m happy you succeeded in testing it because in my case I had not yet the chance to do it! we are departing for summer vacation this saturday!
The idea of using Victron assistants to control the above is definitively a good one!! I only prefer HA as it’s already my main source of automation for everything, including mixed scenario (like disabling in example Power Assist if I turn on a light or a there is an event my calendar or whatever it’s already integrated in HA)
