New system, New to Victron. Would you all mind looking it over?

[Mr_E (Chris)]

I purchased a used RV, and some Victron stuff to upgrade it.

I have a decent knowledge of electrical and solar.

Multiplus II
2 x Lynx Distributors
lynx shunt 1000A
Cerbox GX /w 50 screen
100 | 50 MPPT solar charger.
I am using 4 x Redodo 200AH+, 12 volt, Lifepo4, 200amp BMS in them
And 800watts of solar.

I set this up in what i would think may be an unconventional way. I bought one of those electrical boxes like you would find in an RV park. 100A input, 50, 30, 20 amp receptacles. Connected to AC output 1(#4 between). Nothing connected to AC output 2. With this I just plug my RV’s shore cord into the 30 amp in my case, and the RV thinks its on shore power. All is well.

I know i can connect the RV directly to this system, but this system is total overkill for this RV, and we intend to upgrade RVs in a few years, and i want to take the Victron stuff with me.

I just got it all connected and updated and running a few days ago. Including getting the solar connected. Connected the shore power of my RV to it for the first time yesterday. Still all is well. Tested all items in the RV, all good. Side note, awesome I can gauge the wattage of each device with the VRM app, NICE.

A few details;

Batts are each connected via 7’ 2/0, all parallel into the left dist. 200amp fuses each. (Please check my fuses here)

2 x 2/0 runs into the Multiplus out of right lynx dist. Shunt in between. 200amp fuses each(Please check my fuses here as well)

400amp fuse at the shunt. Blue sea system ANL 400amp here (Please check me)

Cerbo GX powered off the right dist.

The RV connects to the 30amp receptacle, nothing else connected, no other breakers on.

I also have a 100amp 12V distribution box w/fused links running off the right lynx dist. with a 100amp fuse. No loads on it currently.

This question is maybe multifaceted.

I supplied the Multiplus with a 20amp shore power. Set the AC input current limit to 10 amps. I expected to see the Multiplus and the Solar charger pretty much act in concert, as in both be in bulk at the same time for the most part, both go into float at close to the same time, when on shore power. Not the case at all. Initially the Multiplus went into storage, while the Solar was in bulk going gang busters, batts showed around 14.1 in VRM app, 600-700 watts of solar. Then as the sun went down yesterday and the solar died, I then expected the Multiplus to kick into bulk, it did not, stayed in storage, did nothing to charge the batteries seemingly, and then this morning the Multiplus was in Float before solar, still seemingly no charge on the batteries. batts at right around 13.1v. Now i am getting some good charging out of the solar, but the Multiplus still in float. What am I missing?

Regarding SOC, the VRM app shows 100% until the batts. drop below 13.3, then it starts going down, but then had it below 13v yet the SOC still said above 90%. This is my first system with Lithium batteries, so I just maybe don’t understand. Also in the settings, the Multiplus does not show an SOC, maybe relevant.

Current conditions, MPPT in absorbtion makes sense, but Multiplus in Float???

[Skipper]

Did you configure the Multiplus with VE.configure software?

VEConfigure

The MPPT and other devices allow config through Bluetooth, but the Multiplus has to be set with this software package. Also possible through VRM via remote VE.configure if you don’t have the MK3-USB cable.

[Mr_E (Chris)]

I have now, seems better.

Even shows an SOC on the Multiplus settings page now, now as to the accuracy of this, does the system learn this?

[pwfarnell]

The Lynx shunt is the most accurate SOC. It counts current into and out of the battery. When you do a charge to full, the Lynx Shunt sets itself to 100%. It is then pretty accurate but it can drift slowly over time so it needs an occasional recharge to 100% to clear the drift. See this FAQ about optimum shunt settings for synchronisation.

Shunt synchronisation settings

[Mr_E (Chris)]

Thanks for the help, seems like this did the trick on those 2 issues. However now I keep keeping high voltage alarms.

I have the high voltage alarm set at 20 volts, I’ve never seen it above 14.5, but that’s me actually seeing it, in the app, which I’m sure its update rate is far too slow to catch a spike.

Thing is on the advanced page, it shows my max ever voltage as 16 something. What is going on, this has triggered like 10 times today.

Is there a way to see the actual event that triggered the alarm? Such as what voltage it read that triggered, etc… All i can find is the alarm logs, which don’t give any info except its from the battery monitor/Shunt.

[Skipper]

For each alarm you can set a point when it triggers and when the alarm will be cleared. Looks like your high V alarm is triggered at 20V and cleared at 0V.

If you change that to high V alarm at 15V and cleared at 14.6. That would make more sense to me as now the alarm will be cleared when the V reaches 14.6V.

[Mr_E (Chris)]

Thank you, I was going to ask why these sliders have two nodes. Let me try that.

[Mr_E (Chris)]

Seems to have cleared my Alarm issue. Thank you.

Can i go back to the SOC topic. I want to make sure i understand this correctly.

Here are my current settings in the battery tab of the console.

Here is my current status.

So if I understand correctly, I am above 14.2 volts, with a current below 20amps (Tail is at 2.5%, x 800ah = 20amps) so after 5 minutes I should see the SOC reset to 100%, sound, right? I swear it’s been above 14.2 for way longer than that.

[Mr_E (Chris)]

NVMD!!

I literally just watched it reset. Nice. At least i understand how it works now.