Old Magnum MS2812 and new Lithiums

[boondocker]

Yes….upgraded to the ME-ARC50, but that was in 2018 and I think there is a new model for it now.

@Richpatty how did you do the wiring in order to piggyback your victron smart shunt off of the magnum shunt? Series?

 

[Richpatty]

Actually I just hooked up the wires from the magnum right to the Victron smart shunt in the same way you would hook it up to the Magnum shunt. Although the two shunts report slightly different numbers, they are usually close. Generally I go by what the Victron says as it is easier to check via Bluetooth rather than going to the magnum display up front.

Hope this helps
I can take a pic if needed.
Rich

 

[boondocker]

Actually I just hooked up the wires from the magnum right to the Victron smart shunt in the same way you would hook it up to the Magnum shunt. Although the two shunts report slightly different numbers, they are usually close. Generally I go by what the Victron says as it is easier to check via Bluetooth rather than going to the magnum display up front.

Hope this helps
I can take a pic if needed.
Rich

I wired mine in series which seems to be working. Curious what yours looks like if you have a pic of it...

 

[Richpatty]

Hi. Sorry for the delay…

Here are pics of my Victron Smartshunt with the Magnum wires attached. I also attached a pic of the Magnum collection device which is in the adjacent compartment.

Hope this helps.
Rich

 

[Chopperguy]

Hi,
I know this is coming a long time after your note, but I hope you can still see this and are still here.
I have had the oddest thing and extensive testing with input from battleborn, magnum, a genuine rv expert electrical troubleshooter and a ton of headscratching from all......and that is, that with a bank of four battleborn 12v 100aH batteries, all four known to be good individually (we substituted four others, also known to be good and problem is the same, so we know it is not the batteries), and while the batteries register as having a full charge (all settings are absolutely correct in the magnum...I know you have heard this before, but this is the cse)......as soon as the charge is full and the batteries go to rest from a resting voltage of 13.6, the batteries as a bank, drop down to 13.2 in a matter of 10-20 minutes (longer in daytime with solar panels but still "precipitous") and then upon an inverter load, with just a fridge and some 12 volt lights, kind of thing, it is only a matter of another 20 minutes or so before the batteries threaten to go below 13 volts (even at 13.2, the specs show that this is only about a 30% charge but one way or the other, this happens 100% of the time.
there are no other known loads...no ACs runnng...yes, the frdge is a full size but even there, we have replaced it for unconnected reasons and the problem still exists, so it is not that.
we have also tried TWO separate 2812s....both working and tested and STILL no change in the problem.
we can find no ground issues, have triple checked all wiring, have a victron small shunt spliced in so we can also see the voltate on our phone and both the magnum readout inside and the phone show, within a tenth of a volt or so, EXACTLY THE SAME ISSUES.
needless to say we are at wits end.
given your electrician status and that you are an RVer as well, can you opine on this mess? (the panels are connected to a midnite solar controller....all is well, there, too......but even with the batteries showing a full charge and turning the entire solar array off, the precipitous drop is there every time.
tonight, from storm condiitions, the shore power went off and sure enough, from a full charge to 12.9 volts was greased lightning.
can you help?
tnx in advance to you and all and I apologize for th e length of this post but there is a lot going on as you can see.

Hi guys,
I’m experiencing a similar issue and I have found that a faulty battery isolation monitor has resulted in power being directed to my starting battery on the truck. Chassis battery voltage increases. Just a thought for you. Good luck

 

[boondocker]

Hi. Sorry for the delay…

Here are pics of my Victron Smartshunt with the Magnum wires attached. I also attached a pic of the Magnum collection device which is in the adjacent compartment.

Hope this helps.
Rich

How did you wire your MPPT solar charge controller in? Do you have the negative from solar charge controller going straight to the load and charge side of the victron smart shunt or the magnum bmk? Where did you wire the positive side of the MPPT ?

 

[Richpatty]

It’s really simple actually….all positives go to a positive bus bar…and negatives go to a negative one, Except the negative coming off the batteries…that cable goes to the input of the victron shunt. The output of the shunt attaches to the negative busbar. I hope this makes sense.

 

[boondocker]

So you aren't using 2 shunts? One for the Magnum BMK and One for the Victron? I have two setup that I ran in series. I guess I could eliminate the one that came with Magnum and only use the victron.

My current issue is that everything is reading fine except when the solar is charging it is not updating my SOC on the Magnum or the Victron. I know its charging because I see the volts jump but the SOC is not updating and accounting for that positive current.

 

[Richpatty]

I am using just the one Victron smart shunt which reports data via Bluetooth. I ran the wires from the Magnum unit right to the Victon smart shunt, so it is doing double duty. You should be able to see this in my pics in post #79.

 

[Richpatty]

My current issue is that everything is reading fine except when the solar is charging it is not updating my SOC on the Magnum or the Victron. I know its charging because I see the volts jump but the SOC is not updating and accounting for that positive current.

I would be curious if it is the way you have the controller wired…it needs to connect back to where the positives and negative connections come together. That maybe at the battery posts, which is how Newmar has it from the factory. I added the bus bars to make it neater and easier to manage and visualize.