I have a small off grid system which consist from the followings:
- Solar panel 340W / 24V
- SmartSolar Charger MPPT 100/20 (v1.54)
- SmartShunt 500A (software version v4.05) with Temperature sensor (ASS000100000)
- Rospbery PI 3 (software version v2.63)
- Battery Banner EnergyBull 12V 100Ah (C20); Absorption voltage 14.5V; floating voltage 13.5V
DVCC is enabled on the RPI while the Smart Networking is disabled.
During the night the SmartShunt shows a consumption of app 1.3A while at the same time the Charger is showing a consumption of only 0,8A. I have only DC loads that are connected to the charge load output. The only exception is the supply of the SmartShunt, which is connected directly to the positive pole of the battery via the temperature sensor.
The SmartShunt was calibrated as described in the manual.
The SOC is during the night dropping down from 100% to approximately 84,3%. With settings I have managed that the SmartShunt synchronized at the end of the absorption phase. At the moment, of synchronizing the SOC is showing a value of approximately 90,3%.
if a am calculating the SOC with the current shown on the Charger the SOC would drop down app. to 90% and the synchronization would happen close to 100%. In my opinion, the current measured by the SmartShunt is NOK while the current measured by the charger is OK. Also, if I am looking on the discharging and charging energy values over a period of time the discharging energy is double higher than the charged energy.
The second think what I have observed is that during the floating stage of the charger the SmartShunt measure a negative current? This is another reason I think the SmartShunt measures a higher current than it does in reality.
Any Idea how to solve this inaccurate measurement?