ZERO EMISSION VEHICLES AUSTRALIA
4-12 CELL LITHIUM BATTERY MANAGEMENT SYSTEM
Balance voltage
2.00-4.50V,
Dynamic
or Off
The voltage threshold where shunt balancing will
occur. Balancing should only be performed on
cells which are higher than average, so typically
set this to the average maximum charge voltage
of each cell (i.e max charge voltage divided by
number of cells).
Set to 4.51V for dynamic balance voltage or
4.52V for Off.
BMS hysteresis
0.00-0.50V
Applies to Stationary Mode only.
Adds hysteresis
to min/max voltage reset thresholds, so that
charge and load relays are not switched on and
off too rapidly. For example, after an under-
voltage trip, the LV relay won’t be re-enabled
until the cell recovers to 0.2V above Min
Voltage.
BMS min temp
-41C to 100C The minimum allowable temperature for
the battery pack. If a temperature below
this threshold is detected, a warning will be
generated and charging will be disabled.
Set to -41C to disable (will show as “Off”)
BMS max temp
0-101C
The maximum allowable temperature for
the battery pack. If a temperature above
this threshold is detected, a warning will be
generated and chargers and loads will both be
disabled.
Set to 101C to disable (will show as “Off”)
Charger voltage
0-70V
Applies to CAN bus integration with TC Chargers
or SMA/Goodwe inverters only.
The maximum voltage that the BMS will instruct
the charger/inverter to reach.
Charger current
0-100A
Applies to CAN bus integration with TC Chargers
or SMA/Goodwe inverters only.
The maximum current that the BMS will instruct
the charger/inverter to reach.
Stationary mode
No/Yes
Whether the BMS behaviour should be set for
stationary applications. Please see “Stationary
Mode” section for further explanation.
Reverse current display
No/Yes
By default, the BMS12i displays discharge amps
as positive / charge amps negative. If preferred,
you can reverse the display so that discharge
amps are negative / charge amps are positive.
Night Brightness
0-100%
Adjusts the brightness of the LCD display in
low light mode, to reduce screen glare at
night. Toggle between full brightness and night
brightness by swiping a finger up/down.
Buzzer On
Yes/No
Selects whether the Monitor should sound the
buzzer for alerts. (Safest to leave this on.)
Use Fahrenheit
Yes/No
Changes display of temperature units to
Fahrenheit instead of Celcius.
SoC Display
Percent or
Amp-Hours
The battery State of Charge value displayed on
the Monitor can either be shown as a percentage
of full charge, or as the number of amp-hours
remaining.
Stationary Mode
The BMS12i has two main modes of operation, either normal (for mobile / EV applications)
or Stationary Mode (for off grid / backup battery type applications). In normal mode, if an
under- or over-voltage is detected, the LV or HV output relay will be disabled respectively,
and will remain off until the device is either power cycled or (more commonly) they are re-
enabled whenever the device wakes from sleep.
In Stationary mode, the outputs will automatically reset if the voltage recovers sufficiently.
The BMS Hysteresis setting is used to adjust the amount that the voltage needs to recover
before outputs are re-enabled. For example, if the HV output has been disabled due to an
over-voltage cell, a Hysteresis setting of 0.2V will prevent the output from re-enabling until
the high cell has fallen more than 0.2V below the Max Voltage setting.
Common settings for LiFePO4 cells are a
Min Voltage
setting of 2.50V,
Max Voltage
of 3.65V,
and
Hysteresis
of 0.20V, giving a 2.5V-2.7V band for the LV Relay output and 3.45V-3.65V
band for the HV Relay output. LiCo cells have a more linear charge curve so typically need a
smaller hysteresis band around 0.10V, with a
Min Voltage
setting of 3.00V and a
Max Voltage
setting of 4.2V.
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