Current Full Threshold; Open Circuit Voltage Curve; Cell Resistance Estimation; Stack Topology - Nuvation Energy NUV300-BC-12 Product Manual

7.3.3. Current Full Threshold

The current full threshold is another condition that can be applied to determine the full state of the
battery. A battery is not fully charged unless both the full voltage condition is met and the battery
current is above this threshold.
For example, assume ifull = -10000 mA, and charging current icharging = -50000 mA for most of the
charging phase. As battery approaches full charge, the charger tapers off charging current, and when
icharging > ifull, i.e. -9999.9 mA > -10000 mA (AND vcharge = vfull), the battery is considered by
the BMS to be fully charged.
stack_soc.ifull
▪
Defines a maximum current before the battery is considered full
▪
Value must be negative to represent a current in the charge direction
▪
When the current is above this threshold and the full voltage condition is met, then the battery
is considered fully charged

7.3.4. Open Circuit Voltage Curve

Nuvation Energy BMS supports the use of a open-circuit voltage (OCV) table for the battery cells. The
component stack_ocv_lut stores the voltages unique for each SoC percentage (total of 101 entries).
The first table entry represents 0 percent and the last entry represents 100 percent. The voltages
must be consistent with the defined the cell voltage range of
The OCV curve can be used to estimate the SoC of a stack when it is at rest. Contact
support@nuvationenergy.com

7.3.5. Cell Resistance Estimation

The battery management system can be configured to estimate the per cell resistance of every
installed cell during charge/discharge usage. To learn more about this feature and how to configure
and use it, please contact support@nuvationenergy.com.

7.4. Stack Topology

Configuring the battery stack topology requires that the following be specified:
▪
Which cell voltage taps are actually connected to cells
▪
Which thermistor inputs are actually connected to thermistors

7.4.1. Cell Inputs

The Low-Voltage BMS—along with its expansion Cell Interface module—may be connected to fewer
cells than the maximum supported number of cell inputs. The following registers are used to indicate
which cells are actually present in the system. The index n is the zero-based index of the cell input.
Document ID: NE-PM-002
for details on how to perfom this estimation.
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Nuvation Energy Low-Voltage BMS - Product Manual
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Rev 1.2, 2021-03-03
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