Victron Smart Shunt Issues

[1ram]

Has anyone else experienced this issue with the Victron smart shunt? I configured the recommended settings for a LiFePo battery and allowed a full charge, SOC synchronization. What happens next is weird, and has occurred multiple times now.

The shunt consistently shows battery depletion as it occurs which seems normal (i.e. throughout the night), then immediately the next morning it's showing back at 100% SOC when it's clearly impossible, the solar recharge is barely starting to kick in at that point.

 

[BentleyJ]

The setting for "Charged Voltage" is at 52.8V. If I'm reading that correctly, that's the voltage the Smart shunt uses to determine when to reset to 100%. This value needs to be higher.

 

[1ram]

The setting for "Charged Voltage" is at 52.8V. If I'm reading that correctly, that's the voltage the Smart shunt uses to determine when to reset to 100%. This value needs to be higher.

Interesting, I will play with that. My understanding was that it was using current out / current in as the measure of % SOC with these settings

 

[Q-Dog]

Interesting, I will play with that. My understanding was that it was using current out / current in as the measure of % SOC with these settings

It counts current in/out, but in your case if you tell it that fully charged is after it has been at 52.8v for 3 minutes, then it will show 100% 3 minutes after the battery gets to 52.8v. It will keep counting but it won't go over 100%.

 

[BentleyJ]

Interesting, I will play with that. My understanding was that it was using current out / current in as the measure of % SOC with these settings

Yes its called coulomb counting but overtime the accuracy can drift unless the Peukert factor and Efficiency factor are exactly known and never change under any conditions. Therefore the idea is to recalibrate to 100% at the end of each charge cycle which is going to be more like 56V + or - depending on charging C rate, charging Voltage and absorption time.

 

[RCinFLA]

Victron shunt has settings for Columb counter 100% full reset that involves both total battery voltage and charge current taper down level. Both have to be met to reset Columb counter to 100%

You also need to set the battery AH capacity which is the reference for the amp-secs in/out to work against to show % SoC.

 

[1ram]

Yes its called coulomb counting but overtime the accuracy can drift unless the Peukert factor and Efficiency factor are exactly known and never change under any conditions. Therefore the idea is to recalibrate to 100% at the end of each charge cycle which is going to be more like 56V + or - depending on charging C rate, charging Voltage and absorption time.

Seems like 56.62V is the upper limit based on these settings when I look at the history after absorption cycles. I changed it to 56.6V and will monitor how it behaves now.