I have a 9 month old Multiplus 1200/25 Inverter Charger and added Input Power graph to VRM but i just noticed that it shows 940 watts Input , as my battery voltage is 27.5 volts thats over 34 amps , how can that be as the maximum the Multiplus should be charging at is 25 Amps.
@AKO Doesn't quite make sense. Do you have any loads on the AC out? The 25amps is the output so not a fair comparison to the input as there are losses between input and output from the charger but still a 25amp charger at 27.5V even allowing for a 20% inefficiency would be 700w input.
Yes i did have AC loads Jason but thought the Input Power would be what's going into the batteries . Looking at the Output Power graph it was showing around 120 watts at that time which i presume is the consumption of the loads .
Generator started just after 8.30am , takes a min before Charge Kicks in then always up and down like a Yoyo for first 10 mins , no idea why . The output peak a couple of mins later will be freezer cutting in . Generator is 1800 watts nominal with very clean output , voltage and frequency hardly ever varies , its always purring along nicely so well within its capabilities .
Hi @AKO
On your second pic you've named it 'Inverter Output'. But it isn't inverting while the genset is running, it's passing current straight through from the genset to the loads. (The Multi can't actually invert and charge at the same time). Take the load and efficiency loss (guess) off the gen input and you'd be pretty close to maxing your batt charge at 25A.
There's a stock widget called 'VEBus Voltage & Current' which shows the DC A to and from the Multi. That's worth a look, and could be used to assess when the batts can't actually accept current and are nearing full charge.
Your 'Yoyo' is likely the genset baulking at the instant hit on it's output. If you have access to the Multi settings, tick the Dynamic Current Limiter box in General section, and the draw on the genset will be applied over a few seconds rather than all at once. While you're there you could also set an absolute Input Current Limit of (say) 7A @230V to prevent overloading the genset when something unusual might happen. Inverter gensets are pretty sensitive to spikes etc, and they're a pain if they need a manual reset.
Do you have the two separate stock widgets loaded and a shunt to measure the battery separate to the DC Bus?
DC bus voltage and current is not the same as battery voltage and current.
I do have Battery Voltage and current Widgets , was pleased to see your comment that the DC bus voltage and current is not the same as battery voltage and current. which has always puzzled me as the Bus figures are always higher but never by the same margin , can be anything from 0.10 to 0.50 higher . At night with a load and no input from the Array its normally around 0.10 volts higher but today while the generator was running and charging via the Multiplus it was slightly over 0.5 volts higher .
Thanks John , its a learning curve for me , i take your point , the Multiplus cant invert and charge at the same time so my Title is misleading so after reading your observation i have now changed it to AC LOAD so I'm hoping I'm correct is thinking that the graph shows the output from the Multiplus either when Inverting or with generator AC passing through .
Looking at the widget you suggested i think it could be worth adding , would i be right in thinking that its showing the output from the Generator via Multiplus to the batteries as the Generator is the only source i have other then the Array . I did notice that the current varies between 24.8 and 25.3 Amps and as its a 25 amp Multiplus charger it would make sense if it was .
As a side question which would be the better option . Before fitting the Multiplus i had a good quality Battery charger connected via a switch so i could select either Charge batteries only or Charge Batteries and sent power to the house also at the same time , would the second option help in the Yoyo effect in getting from the Multiplus if your suggested settings dont solve the problem ..
C'mon now, have faith! I wouldn't bother with an alternative charger switching setup. The way the Multi's system works is that it gives best value when actually using the genset. Like you can set it's output (via the Multi) to where it's comfortable, and it will cover ac loads and use the remaining power to charge. So you get constant load on the gen. But sometimes a genset may not be accepted, or coughs itself at being accepted. This can be dealt with easily in most cases ( https://www.victronenergy.com/live/multiplus_faq), but if you exhaust those options I can probably find more. Your challenge is to find and set the limits where you get reliable operation and best value.
Your discussion with @Alexandra reminds me of myself before I grabbed a Smartshunt. I thought I was fine without it too, but it taught/enabled me to use a genset and my batts more efficiently. Would have paid for itself many times over. Don't dismiss, especially with a GX device in the system.
Dynamic Current Limiter box ticked , it wasn't ticked before
Input Current Limit set to 7 amps , was 12 amps before
UPS FUNCTION left Unticked .
Charger selection switch was fitted after having tried the Multiplus several time without success . When generator was connected the yellow charge light would only flash , couldn't get a steady on illumination . I have now overcome the problem but no idea how it works but it does , the sequence i have to go through is :-
Connect generator with Multiplus switch in normal INVERTER/CHARGER position ....After a min or so lights change to flashing Yellow Charge
Disconnect Generator and switch Multiplus to CHARGER only ...Charger Light constant steady illuminated
Disconnect Generator and set switch back to INVERTER/CHARGER position ...After a min or so the charger light is constant steady illuminated .
With my other Charger i can see how many amps are being sent to the batteries starting at 28 amps i leave it charging until its down to 10 amps when i turn the generator off as its not viable to leave it running . Is there any widget that would show how much of the generator charge was being sent to the Battery Bank or is it just the Overall Input current only which i found i can get from system - Genset ?
I am in Spain so i dont often need to use my Generator however when i do with my other Battery charger i would use at night for 3 or 4 hours when we have had a day of bad weather and the input current would drop as the voltage rises in the same way an Solar charger would work . The Multiplus i find i would not use it until the following morning when the voltage is at its lowest and then just for a couple of hours as i don't need more than the Bulk charge .
You shouldn't need to go through that procedure. The 7A Input limit should help, but go even lower as a test if it doesn't. There is a low limit that you can't set below, so if you strike that don't worry.
If the genset is inverter regulated it may be tripping off itself. And that may explain why it comes back when you reconnect it. If it has ECO mode, don't use that. If it has 2 ac out ports, hook a light or something to one so you can see if the genset has tripped. The aim here is to find which one, the genset or the Multi, is causing this.
Unless you have dc loads the widget I suggested would be close for the Charge Current. That figure should also show on the GX screens.
Firstly thank you for bearing with me and explaining what im stil trying to get my head around John .The generator is a year old Honda 2200 Inverter type and without Eco mode it runs like any none inverter generator , its only when Eco mode is selected that the running speed is increases and decreases with the loads , its peak at 2200 watts and 1800 watts nominal , the maximum i have drawn from it according to VRM genset widgets is 940 watts and when the Multiplus does connect the generator doesn't miss a beat or struggle , the load is also sent through to the house and we have confirmed that there is no interruption to the load . Once the Multiplus is charging the batteries i switch it to Eco mode and the revs drop right down so it clearly working well within its capacity , about 50% . After going through changing the multiplus switches to get it to charge i have even had the generator running on Eco mode when the Multiplus is connected and although the revs increase its nowhere near as fast as it is without Eco mode so it copes with changing loads without problem .
I understand you point about without loads then the graph would basically only show what was being sent to the batteries however the widget is confusing as when the custom widget for just the Genset Input is showing 940 watts the VEBus Voltage & Current is showing only 25 Amps . I understand the the 940 watts is the output from the generator including loads but the 25 amps are shown at the same time , surly they cant both be right . .
Yeh, the ECO thing works differently on some gensets. I've seen them do what you describe, then I've a 6kVA Yamaha (AVR regulated) which goes to full revs in ECO when it's connected to a 5000 Multi, even before the Multi has accepted it's output. So the Multi is doing something to it's non-flowing output that I don't understand. Fine you're beyond that stage, but I added that in so that it wouldn't be one of several issues you might strike.
All gensets are different, and weirdness sometimes arrives unexpectedly. Eg. mine can only handle 13A (230V) input when charging, higher causes rejection by the Multi. Yet add on a 2000+W load and I can wind that up to 25A no problems. So you need to roll with these little things sometimes and experiment. They ain't documented anywhere..
The power balance you'll need to keep chewing on. A shunt and a GX device helps a lot to understand, but I'm not trying to sell you. And even then you get stuff like this.. 
The Multi & shunt always the same V and A in my nighttimes, but always 30-40W different. Lost to the efficiency/standby ether..
The dealer when selling me the Multiplus did say they always need a bigger generator than you wil realise , we fit a lot of these Inverter Chargers then see generators that should run them easy not being able to cope and the customer having to buy larger ones or go down to a smaller Multiplus , i wanted the 1600 but they said a genny with just 1800 watt nominal output wouldn't run it even if its set to Charger only although it has no problem running a larger conventional battery charger
And I have a 5000 and could easily run your genset, even smaller. And I have. Not outta the box though, needs adjustment to the Multi settings with the loads/charge I sometimes run. Some gensets though are prepackaged landfill straight from the shop, with capacitor regulation and voltage sag that would make you cry. Fine for camping lights, little more.
Had the opportunity with bad weather to try some things with your suggested settings . The Multiplus started as always with flashing yellow so last night i didn't bother disconnecting and reconnecting the generator between switching to Charge only and back , i just switched Multiplus OFF at its switch then back ON , it worked , the yellow charge light was steady and stayed on . As i hadn't tried that before i don't know if it would have done the same previously but at least it saves a lot of messing about , a quick switch OFF then On ant its charging as it should .
This morning al i did was turn the output from the Inverter to the house and when i connected the generator it want straight to a steady Yellow Charge light . the house was drawing about 200 watts that's all so i don't know why that would have made any difference as even when connected again the Genny was outputting less than 1000 watts , well within its capabilities .
The Multiplus doesn't seem to be using temperature compensation , it goes from Bulk to Absorption at the set voltage of 28.8 volts even though the temperature was below 20c . I have the temperature sensor connected tot he Cero and DVCC on for only Temperature and the temperature its showing is correct as the same as the MPPT which had its own identical temperature sensor and increasing the end of bulk at 29.10 which iis what i calculated it should be . Is DVCC known to be unreliable or the Multiplus temperature compensation in general as with temperature changes here it can mean as much as 1.6 volts either way depending on the time of year .
Sorry, I missed this post (use the '@' feature if you want someone to get notified).
Good you're making some progress. The Dynamic Current Limiter is really essential with small gensets. But regardless, the Multi might still take like 20sec or so to switch it in. Once you're more confident, you could experiment with the Input Limit, but don't do this without a demand for it at the time. This can be changed from the GX or other ways too.
Re the Temp Comp, DVCC is usually ultra reliable passing on T. Make sure you actually have a T reading, DVCC should show it as recognized, you should see it in VRM too. And of course there's a setting in the Multi for the compensation factor (don't forget the minus sign). If you struggle with this, maybe start a separate question.
