Hi everyone,
I have a RV with 2x 105Ah Lithium Batteries from Bulltron and, beside other components, a SmartShunt 500A / 50mV. I also have a solar panel and a MPPT but, when not used the RV is under a roof with litte light. In summer I get some charge from it, but not now, in the winter. Charging from the alternator and 230V ist done via a Votronic VBCS Triple.
When not used for some time I switch off the batterie via the remote control signal of the BatteryProtect. Then only the BatteryProtect, the SmartShunt, two MPPTs and a SmartInverter, which is also disabled via remote control signal, are still active. In this state daily power consumption is around 2,5Ah, according to the SmartShunt. This is the same, no matter if I set the current threshold in the SmartShunt to the default of 0,1A or 0,01A, as it is currently set.
The last time I checked the RV the SmartShunt displayed a SOC of 50% and a power consumption of 126 Ah after 52 days without charging. As far as I know, this is because it takes into consideration that the battery capacity is somewhat higher when the discharge current is low.
Then I first drove around 30min, with a charging current, according to the SmartShunt, of around 50A, after that I plugged in 230V with a charging current of 20A. After around 1:35h the current started to drop significantly and shortly after that the SOC changes to 100% (default settings for lithium batteries in the SmartShunt). I also checked the BMS of the batteries and it too reported a SOC of 100%, so I assume the batteries are really fully charged.
When evaluation the current, as measured by the SmartShunt, I can roughly estimate a charged energy of 75Ah, which is only 60% of the power consumption displayed by the SmartShunt.
Now I am wondering if this is to be expected and if there is anything I could do to improve the accuracy?
Thanks in advance,
Meleager