New Multiplus II cycling off and back on when a Smart Dongle or CerboGX is added. Inverter runs fine by itself. When AC from Honda EU3200 is present system charges and is stable with Smart Dongle, reporting data etc. Cycling starts when AC input is removed and inverter cycles off and back on about twice per minute. Battery is LiTime 24V 230AH with 200A BMS. No error codes.
Have spent hours trying configurations, cables, reboots and suggestions from chatGPT. Have built two minimal Victron systems in the past without issues. Have tried two new Smart Dongles, a new CerboGX and display, updated firmware, and many other things. The only thing that works properly is the MultiPlus II by itself. Have the USB Programmer and worked through the settings both with Victron Connect and later with VE Configure. Have done reset to factory settings.
Now ChatGPT is telling me that a SmartShunt is required for the Smart Dongle or Cerbo GX to maintain the inverter on. I do plan to put a smart shunt on the system but am camping in the desert and don’t have it with me, was trying to keep things simple for now. There are no 24V loads or chargers other than the Multiplus II.
This -like much of LLM’s advice- is not at all correct. LLMs are kind of known for just making stuff up, which is why most knowledgeable people will advise never asking them any question you don’t already know the correct answer to.
I don’t have additional input for you, without inspecting your system in person, but this part at least is definitely not true. Perhaps leave the unit operating in standalone mode, since you mention it works fine that way, until you get back to civilization and can have an experienced systems installer go through it for you?
I don’t trust LLMs too far but they are useful for a lot of things and I’m glad to hear that rather suspicious claim is false, which doesn’t surprise me. I would be interested in what settings might cause cycling or prevent it. I’ve gone through every setting several times and tried three different controllers, all new gear, several RJ cables, and have worked with Victron before (am an Electrical Engineer and a Software Engineer) so I’d like to hear what settings might be wrong. We’ve turned off most everything, reset to factory defaults, no error codes, etc. My two other Victron systems have never demonstrated this behavior but they were Multiplus pre II’s. Thanks for any useful comments.
Cabling is short 2/0 (under 2 feet each polarity), 400A DC breaker, with manual precharge circuit using a momentary pushbutton and resistor. It does work fine with Smart Dongle or Cerbo GX while Charging, it’s only in Inverting mode that cycling occurs when VE.Bus is connected from Multiplus to Smart Dongle or Cerbo. At the moment I’m leaving the VE.Bus cable unplugged with a Smart Dongle so I can at least monitor the voltage and temperature. While the EU3200 generator is running and the system charging I can plug in the VE.Bus and control the input AC current limit and monitor the process normally. Temperatures are 17-27C at the battery. The Smart Dongle has been moved to the Battery, here it is shown on the MP2.
I designed and 3D printed a case for the breaker with the precharge circuit. The momentary switch has a 12-24V LED built in so you can see the state of the precharge. Takes about 5 seconds to fully charge.
No suggestions? ChatGPT says it needs a shunt for the smart dongle or Cerbo to stay on, it does appear that as soon as the dongle or Cerbo reads the status they send a turn off command to the Multiplus, so it goes off, then a few seconds later it comes back on and the cycle repeats.
AES is not enabled. Good to know that it can work without a shunt, though I’m going to install one soon, that’s what I experienced in the past but not with this setup and current firmware. Well, to be precise, the inverter stays on fine without the GX. It’s apparently the GX that is turning the inverter off. Both Smart Dongles and the GX behaved the same way, when the VE.bus was connected they would get data and then turn the inverter off. Then it would turn back on and cycle. The inverter wanted to be on.
