Smart Shunt reading (-) amps after "full charge"

[cruxarche]

I have been running a fridge and a water pump off solar/ battle born setup for several months. Even in winter the loads almost never exceeded the daily energy production of the panel. Yet, my smart shunt reads (below) -4.2 Ah at the end of the day. It stays in float mode as thought it is fully charged. Today I unplugged the load and just let it charge. It did not change. Still reads -4.2. Am I missing something really basic here?

Thanks.

System:
300 watt panel
Victron Smart shunt
Victron Smart Solar 75/15
Battle Born 50 AMP

 

[dstefan]

Battleborn’s advice to me was to be sure the battery is charged to at least 14.2 periodically to calibrate the top balance in the BMS. Are you getting there with your setup? I“m no expert on this at all, but I kinda wonder if it’s something like that, or you need to resynch the 100% setting in the app?

If you charged it all day with no load and adequate current and max voltage and it”s showing 13.43 then its essentially 100% charged, I believe. I’ll be interested to hear if there’s some other reason, but the readout may just need to be reset in the app.

 

[cruxarche]

I just noticed my "charged voltage" setting in the smart shunt was set too low (13.8). The MMPT was set according to battle born specs. It it occurs to me I do not really understand the interaction between the smart shunt and the charge controller, so i do not know if the lower setting on the smart shunt could have been impacting the charging. Either way, I adjusted the setting on the smart shunt, unplugged all loads and the charge controller, and am charging with the Noco.

 

[cruxarche]

The Noco finished charging with mixed results: higher voltage but same 92% and negative Ah.
14.27V
4.3 Consumed Ah


EDIT**************I guess i need to be more patient. After a while it reset itself to 100% charged and 0 Ah consumed.

 

[Superduty]

I am no expert either, but at some point when the charge is at 100% you need to tell the shunt that it is now at 100%. I suspect it is best to tell it 100% when there is no draw on the battery. Then it will monitor how much leaves the battery and how much comes in to give you an accurate percentage.

There are some experts here on the portal that I am sure will contribute to this thread. There is also a Victron FB group that has some experts.