…..at the risk of asking a silly question:
I’m using the BMV-712 Smart to monitor:
an electric motor with 48 volts
4 × 12 V 120 Ah AGM batteries connected in series.
I have set the discharge floor to 50%.
On the screen / see image, I have a state of charge of 77%.
Does the state of charge refer to the batteries’ total remaining capacity, meaning that in this example I would have 27% left after deducting the discharge floor?
Yes, with lead-acid batteries, 50% is generally the limit. Of course, you could still draw considerably more from the battery, but that wouldn’t be good for it.
If you have four batteries connected in series, the total capacity remains 120 Ah.
So far, 100% − 77% = 23% of 120 Ah has been drawn, which works out at approximately 27 Ah.
The discrepancy compared with the nearly 20 Ah measured can really only be due to the charging efficiency. It’s probably set to around 85%.
