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michael shore avatar image
michael shore asked

MULTI PLUS COMPACT WORKS WITH LITHIUM NOT AGM

I moved my functioning RV solar setup into my basement for use as UPS backup on a sump pump. In the new set up I have not connected the solar panels and I have substitutes the 2 Victron lithium batteries (160AH each) with one AGM battery (100AH). The system is connected to the mains. With the AGM battery (only) connected and the mains cut off, the inverter will "click" but there is no power to the AC out put. I assume the click is a transfer switch or an alarm relay. There is a long pause between power cut off and the sound.

With the lithium batteries re installed (AGM removed) and the mains cut off the inverter supplies AC power as it did in the RV.

I interpret the error LED on the Multi when only the AGM is connected to be indicating "Low Battery". Multimeter shows AGM battery at 12.5VDC.

I don't want the Lithiums in the basement. What set up points am I missing? Which, if any, of the shunts, relays, MPPT components particular to lithium batteries do I need to remove to use the AGM battery.

I built this system in 2018 from dealer supplied drawings as a "kit" . It has worked well. The dealer is on the West coast. I am now located in the North East. I might qualify as an amateur. I am happy to supply more details towards getting this system functional.

AGM Battery
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kevgermany answered ·

Assuming there's nothing else on the system, you're going to need an mk3 to usb adapter and VR config software on your pc to diagnose further.



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pwfarnell avatar image pwfarnell commented ·

@michael shore Or if you have an Android phone a mk3 to usb adapter, an OTG cable and Victron Connect.

https://m.youtube.com/watch?v=ZCuG_EgXSJc

The most likely issue is the low voltage shutdown setting(s) have been set for lithium and are too high for AGM but you need to read what the settings are.

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michael shore avatar image michael shore pwfarnell commented ·
treasure of help, thank you. I suspected the settings but did not know where to edit them or the correct parameters.

Not whining (much) just appreciating the learning curve.

I do have the connection device (MK3 to USB) but so far have not been able to access the proper web page and have been intimidated by warnings that certain settings are for "pros" to deal with. When I approached the page it seemed to want me to be a pro with a special identity code.

My 5 year old iPhone does not have the proper port so I am connecting with an up to date iMac.

Thank you again for there leads to answers.

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kevgermany avatar image kevgermany ♦♦ michael shore commented ·
First thing to do is download and save a copy of the settings. Then explore all the options, but change nothing.

The software helps by showing altered values in a different colour, red.

Take a look at the inverter input settings. With AGM, best to experiment, but you may need to drop as low as 11.5. Under heavy load, the voltage drops rapidly, but recovers once the load is removed.


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