Battery Monitor BMV-712 Data- User error or Bugs?

DIY
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1

I am using Battery Monitor BMV-712 Smart to track data with the Victron Connect App on Android.

Unfortunately, I have not been able to display the “Consumed Amp Hours (Ah)” Graph on the app. It only shows a trace when Consumed Ah=0 and the y-axis on the graph (Ah) doesnt seem to scale (Should go down to -30Ah example).

SOC_Consumed_AH
SOC_Consumed_AH417×887 44.9 KB

Secondly, the logic is not functioning properly in regards to State of Charge vs. Voltage.
In the picture below the graph shows State of charge increasing to 100% and staying there when the voltage drops.

Presumably, the BMV “thinks” that it is in “Float.” However in this case a cloud came over head, which accounted for the voltage drop. The Solar Charger is still in “Absorbtion”

SOC_Voltage
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Im wondering if these are bugs or am I missing some setting.

Seems to me there are problems in both the app (displaying consumed Ah y-axis) and the BMV firmware itself for going to 100% SOC on Voltage drop from lack of sun.

I have meticulously read the manuals of both units and adjusted the battery settings for Peukert, Charged Voltage etc. according to manufactures specs and actual tests.

Please Advise

Gear:

Victron Connect App (Android) V6.16

Battery Monitor BMV-712 Smart Firmware 4.16
BMV-7xx Smart Bluetooth Interface Firmware 2.52 bootlader 1.18
Smart Solar Charger MPPT 100/30 Firmware 1.64
Smart Solar Bluetooth Interface (Rev3) Firmware 2.52 bootlader 1.18

Connected VE.Smart Networking
Battery Voltage
Battery Current
Battery Temp.

2

I can not answer questions on the app as I do not use it for monitoring.

However, the jumping to 100% is not a bug, you need to adjust your settings for solar use, see my FAQ about SOC jumping to 100%. The settings are slightly at odds with the manual, but mine work better with solar. It explains why.

SOC jumping to 100%

3

@pwfarnell Thanks for the detailed suggestions.

The charged detection time seems to apply best in this case. I changed it to 5M as you suggested.

Ill see if that works then Ill look into the tail current settings for both units.

In the past I have set charged voltage setting to the absorbtion voltage, but that didnt work. I dont remember exactly but I think the SOC never reached 100% and would keep going down everyday.

4

Why cant the Float state just be transmitted on the network to indicate 100% SOC to the BMV? I guess this is more of a feature request.

5

Plenty of cases on here of chargers going in to float early because the charger is incorrectly set up or seeing voltage drop. Set up right, the shunt chooses the correct point, just under absorb voltage and low current means full. I can not see this being changed.

6

The time may help. Setting the charged voltage to the absorb voltage is a losing strategy because due to slight discrepancies the shunt may always read slightly lower. The key is setting the charged voltage just below absorption and not having too high tail current.