Your Battery Monitor, Smart Shunt or BMV might be giving you the Wrong State of Charge | Here is Fix

[@AllanMain1776]

This may be my solution. The other day I turned off the battery disconnect for 12 minutes, with the SOC around 65% I turn the disconnect back on and the SOC shows 100%. All week I've been battling a charging system that will not charge my batteries because it sees a SOC at 14.5v, but the batteries are each charged at 12.91v. 3 Battleborn Gamechangers, installed in our Cirrus 920 camper. I'm considering disconnecting the system side of the Smart Shunt and resetting to zero calibration when I am certain there is no current in the system. You video seems to support that a sudden spike in SOC may be to blame for by batteries not accepting current. Thanks in advance.

[@nebulight]

You didn’t mention internal battery heaters with soc in the other direction. You may think you’ve got 15-20% left but you are almost at zero.

[@sotasolar]

That’s a good point. Most heaters late only heat from incoming cu and don’t self deplete, however that can be the case.

[@nebulight]

@@sotasolareither method is bad. With self heating it’s using up power that the battery monitor doesn’t know about. Battery monitor SOC stays the same but there could be as much as a 5amp load in the battery depending on battery. Then if it only takes it from the charge source, the bmv will count that as charge current and increase your SOC but in actuality the SOC hasn’t change as not REAL charge current is getting applied.

[@tedhamilton2362]

I find that if load is around/under 200watts for extended periods (2-3 days), my BMV SOC can lose accuracy. However, if I can reach full battery charge and 100% every day and then see absorption and then float, I see improved SOC accuracy.

[@richardroberts1090]

my BMV 712 seemed to report empty battery then just stopped working. Have since installed the Victron Lnyx Shunt.

[@beefitter]

Great video. Being that you are a Victron dealer, any idea when the 48v 5k Multiplus gets its UL rating? That has been pending now for almost a year.

[@sotasolar]

Nope, we don’t get much advance info.

[@markratliff7991]

Shawn, I have a SOC related question. I have (2) 206 Ah SOK batteries in parallel monitored by a Victron SmartShunt. It currently reads 100% SOC with a 13.81 V and 0 Amps. When I connect via BT to the BMS of each of the SOK batteries I get 100% SOC on one battery and 79% SOC on the other battery. Both BMS's show 13.8 V and 0.0 A. Any idea why the discrepancy between the BMS SOC readings? Does the SmartShunt measure SOC of both the batteries since they are in Parallel? Love your channel!

[@sotasolar]

One of the SOK batteries could need internal balancing. Re start bulk charging and watch that lower SOC battery. See if it becomes full.

[@sdfaulk01]

Off topic question, have you heard anything about the Cerbo beta you showed a few months ago coming to final version release?

[@sotasolar]

It continues to improve there is a lot of work still to be done. The community forums have the most updated information.

[@wdafchuck]

Why would I get a discrepancy, or conflicting/different readings IE: 14.2 at the shunt and 13.9 from the Multi dongle? Also, SOC stays up, and voltage drops to low cutoff prematurely when boondocking

[@sotasolar]

Are you on lithium or lead acid? The dongle will sometimes report a lower voltage. We’ve seen it.

[@wdafchuck]

@@sotasolar 800ah lithium (8x100) We spoke to you awhile back and you helped with cleaning the current sense on the multi 3.5mm jack

[@sotasolar]

@wdafchuck oh, I remember now. Verify with a multimeter where the voltage is getting to. Could try and raise the absorption voltage to 14.4 if the dongle is reading low, it can affect the charging characteristics. You can also look into a warranty replacement on the dongle. I had a customer a while ago who needed to that.

[@wdafchuck]

@@sotasolar will do as soon as we get back into town. Thanks again !!!

[@2hotscottpro]

My shunt showed 2ah consumed.I shut off charge inverter to reboot and those 2ah went away showing 100%. And was still charging that 2ah Using $100 victron shunt and app.