REC ACTIVE BMS User manual

Rozna ulica 20, 6230 Postojna, Slovenia
e-mail: [e-mail]; www.rec-bms.com
1
VICTRON CCGX-SUPPORTED ACTIVE BATTERY
MANAGEMENT SYSTEM REC ACTIVE BMS
Features:
-robust and small design
-4 cells
-single cell voltage measurement (0.1 –5.0 V, resolution 1 mV)
-single cell - under/over voltage protection
-single cell internal resistance measurement
-SOC and SOH calculation
-over temperature protection
-under temperature charging protection
-active cell balancing up to 2.5 A DC per cell
-shunt current measurement (resolution 19.5 mA @ ±500 A)
-galvanically isolated user defined multi-purpose digital output
-programmable relay (normally open or normally closed)
-galvanically isolated RS-485 communication protocol
-CAN communication (Victron compatible)
-error LED + buzzer indicator
-12 ERROR log on the device FIFO
-PC user interface for changing the settings and data-logging (optional accessory)
-hibernate switch
-one IP65 protected connector for all connections
-one-year warranty

BATTERY MANAGEMENT SYSTEM ABMS FOR VICTRON COLOR CONTROL GX
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General Description of the BMS Unit:
The Battery management system (BMS) monitors and controls each cell in the battery pack by measuring its
parameters. The capacity of the battery pack differs from one cell to another and this increases with number of
charging/discharging cycles. The Li-poly batteries are fully charged at typical cell voltage 4.16 - 4.20 V or 3.5 –3.7 V
for LiFePO4. Due to the different capacity this voltage is not reached at the same time for all cells in the pack. The
lower the cell’s capacity the sooner this voltage is reached. When charging series connected cells with a single
charger, voltage on some cells might be higher than the maximum allowed voltage. Overcharging the cell
additionally lowers its capacity and number of charging cycles. The BMS equalizes cells’ voltage by diverting some
of the charging current from higher voltage cells to the whole pack or from the whole pack to a lower voltage cells
–active balancing. The device’s temperature is measured to protect the circuit from over-heating due to
unexpected failure. Battery pack’s temperature is monitored by Dallas DS18B20 digital temperature sensor/s.
Current is measured by a low-side shunt resistor. Battery pack current, temperature and cell’s voltage determine
state of charge (SOC). State of health (SOH) is determined by comparing cell’s current parameters with the
parameters of a new battery pack. The BMS default parameters are listed in Table 1.
Hardware parameters:
Table 1: ABMS hardware parameters.
Parameter
Value
Unit
BMS maximum pack voltage
16.8
V
BMS maximum cell voltage
5.0
V
Shunt common mode input voltage interval (Shunt+, Shunt -) to
the Cell 1 negative
-0.3 to 3.0
V
Shunt sensor differential input voltage interval (Shunt+ to Shunt -)
-0.25 to 0.25
V
max DC current relay @ 60 V DC
0.7
A
max AC current relay @ 230 V AC
2
A
max DC current @ optocoupler
15
mA
max DC voltage@ optocoupler
62.5
V
BMS unit disable power supply
< 1
mW
BMS unit stand-by power supply
< 60
mW
BMS unit cell balance fuse rating (SMD)
3
A
internal relay fuse
2 slow
A
dimensions (w × l × h)
105 x 135 x 44
mm
IP protection
IP65
Default Software Parameters:
Table 2: Default BMS parameter settings.
Parameter
Value
Unit
chemistry
3 (LiFePO4)
n.a.
capacity
720
Ah
balance start voltage
3.45
V
balance end voltage
3.58
V
maximum diverted current per cell
up to 2.5 (5 pp)
A
cell over-voltage switch-off
3.85
V
over-voltage switch-off hysteresis per cell
0.25
V
cell end of charge voltage
3.58
V
End of chrge hysteresis per cell
0.25
V
SOC end of charge hysteresis
5
%
cell-under voltage protection switch-off
2.8
V

BATTERY MANAGEMENT SYSTEM ABMS FOR VICTRON COLOR CONTROL GX
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under voltage protection switch-off hysteresis per cell
0.1
V
cell under voltage discharge protection
2.9
V
pack under voltage protection switch-off timer
4
s
cells max difference
0.25
V
BMS over-temperature switch-off
55
°C
BMS over-temperature switch-off hysteresis
5
°C
cell over temperature switch-off
55
°C
under temperature charging disable
-15
°C
voltage to current coefficient
0.01953125
A/bit
current measurement zero offset
0.0
A
maximum charging/discharging current per inverter device
50/120
A
Number of inverter devices
1
n.a.
Charge coefficient
0.6
n.a.
Discharge coefficient
1.5
n.a.
relay 1 voltage level
3.58
V
relay 1 voltage level hysteresis
-0.2
V
optocoupler 2 voltage level
2.9
V
optocoupler 2 voltage level hysteresis
0.2
V
CAN communication frequency
250
kbit/sec
System Overview:
Figure 1: System overview.

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BMS Unit Connections:
Figure 2: BMS unit front panel function overview.
Table 3: BMS unit male socket connections.
Connection
Designator
Description
1
relay 1 –user defined
Normally closed
2
relay 1 –user defined
Fused input
3
Main relay
Normally closed
4
Main relay
Normally open
5
Main relay
Fused input
6
Hibernate switch signal
-
7
Hibernate switch ground
-
8
Cell 4 positive +
Analog signal
9
Cell 3 positive +
Analog signal
10
Cell 2 positive +
Analog signal
11
Cell 1 positive +
Analog signal
12
Cell 1 negative -
Analog signal
13
relay 1 –user defined
Normally open
14
Charge Optocoupler collector
-
15
Charge Optocoupler emitter (darlington + reverse
protection diode + polyfuse)
-
16
Optocoupler 2 –user defined collector
-
17
Optocoupler 2 –user defined discharge emitter
(darlington + reverse protection diode + polyfuse)
-
18
CAN Vcc
4.6 V output, max 10 mA
19
CANL
-
20
RS485 Vcc
-
21
RS485 A
-
22
RS485 ground
-
23
RS485 B
-
24
Shunt-
-
25
Shunt+
-
26
Shunt shield
-
27
Dallas 18B20 temp. sensor
GND + shield
28
Dallas 18B20 temp. sensor
+ 5 V
29
Dallas 18B20 temp. sensor
1-wire digital signal
30
CANH
-
31
CAN ground
GND potential of the battery pack
32
-
-
33
Address pin 3
Normally 0, connect to pin 35 to
change to 1
34
Address pin 2
Normally 0, connect to pin 35 to
change to 1
35
Address pin ground
Fused ground for Address pins

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Setting the RS-485 Address:
Address of the BMS unit is selected via the Address pins. Factory address is 2. Formula for changing the address is:
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  
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 
! If multiple BMS units are used distinguished addresses should be set to avoid data collision on the RS-485
communication bus!
BMS Unit Connector:
Before starting the assembly please go to website:
http://www.te.com/catalog/pn/en/776164-1?RQPN=776164-1
…and read the connector assembly datasheet:
AMPSEAL Automotive Plug Connector and Header Assembly in Application Specification and
AMPSEAL Automotive Plug Assemblies 776268… in Instruction Sheet (U. S.).
BMS Unit Connector, Cells part:
Connect each cell to the BMS unit cell connector plug. Use silicon wires with cross section of 0.5 –1.4 mm2(20-16
AWG). !Before inserting the connector check the voltage and polarity of each connection!
Figure 3: Battery pack connection plug –front side.
BMS Unit Power Supply:
BMS unit is always supplied from the 4-th cell connection.
BMS Unit Connection Instructions:
Connect all necessary connections to the BMS connector first, check the polarities and then plug the female
connector into the BMS. When the system components are plugged in, the enable switch can be turned ON and
the unit starts the test procedure. Connection instruction video link: http://www.rec-bms.com/ABMS.html
When disconnecting the unit from the battery pack, the procedure should be followed in reverse order.

BATTERY MANAGEMENT SYSTEM ABMS FOR VICTRON COLOR CONTROL GX
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RS-485 Communication Protocol:
Figure 4: RS-485 DB9 connector front view.
Table 4: RS-485 DB9 connector pin designator.
pin
designator
1
-
2
AGND
3
B
4
A
5
-
6
+5V to AGND
7
-
8
-
9
-
Galvanically isolated RS-485 (EN 61558-1, EN 61558-2) serves for logging and changing BMS parameters. Dedicated
PC BMS Control Software or another RS-485 device may be used for the communication. Default RS-485 address is
2.
Unlock password: Serial without the first minus e.g. 1A-XXXX.
Messages are comprised as follows:
STX, DA, SA, N, INSTRUCTION- 4 bytes, 16-bit CRC, ETX
STX start transmission <0x55> (always)
DA - destination address <0x01> to <0x10> (set as 6)
SA - sender address <0x00> (always 0)
N –number of sent bytes
INSTRUCTION 4 bytes for example.: 'L','C','D','1','?', - (combined from 4 ASCII characters, followed by ‘?’, if
we would like to receive the current parameter value or ‘ ’,’xx.xx’ value in case we want to set a new value
16-bit CRC - big endian, for the whole message except STX in ETX -
https://www.lammertbies.nl/comm/info/crc-calculation.html
ETX - end transmission <0xAA> (always)
Dataflow:
Bit rate: 56k
Data bits: 8
Stop bits: 1
Parity: None
Mode: Asynchronous
Little endian format when an array is sent

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Table 5: RS-485 instruction set.
INSTRUCTION
DESCRIPTION
BMS ANSWER
SETTING INTERVAL
*IDN?
Identification
Answer “REC - BATTERY
MANAGEMENT SYSTEM”
Read only
ARRAYS INSTRUCTIONS
LCD1?
Main data
First answer is 28 –how many byte
data will be sent and then data
message follows as 7 float values:
LCD1 [0] = min cell voltage,
LCD1 [1] = max cell voltage,
LCD1 [2] = current,
LCD1 [3] = max temperature,
LCD1 [4] = pack voltage,
LCD1 [5] = SOC (state of charge)
interval 0-1-> 1=100% and
LCD1 [6] = SOH (state of health)
interval 0-1-> 1=100%
Read only
LCD3?
Main data
First answer is 8 –how many byte
data will be sent and then data
message follows as 8 byte values:
LCD3 [0] = min cell BMS address,
LCD3 [1] = min cell number,
LCD3 [2] = max cell BMS address,
LCD3 [3] = max cell number,
LCD3 [4] = max temp. sens. BMS
address,
LCD3 [5] = max temp. sens. number,
LCD3 [6] = Ah MSB,
LCD3 [7] = Ah LSB
Read only
CELL?
Cell voltages
BMS first responds with how many
BMS units are connected, then it
sends the values of the cells in float
format
Read only
PTEM?
Cell temperatures
BMS first responds with how many
BMS units are connected then it
sends the values of the temperature
sensors in float format
Read only
RINT?
Cells internal DC resistance
BMS first responds with how many
BMS units are connected then it
sends the values in float format
Read only
BTEM?
BMS temperature
BMS first responds with value 1, then
it sends the values of the BMS
temperature sensor in float format
Read only
ERRO?
Error number description
array
First answer is 4 –how many byte
data will be sent and then data
message follows as 4 byte values:
ERRO [0] = 0 –no error, 1 –error
ERRO [1] = BMS unit
ERRO [2] = error number (1-14) and
ERRO [3] = number of the cell, temp.
sensor where the error occurred
Read only
CELL SETTINGS INSTRUCTIONS
BVOL? or
BVOL x.xx
Balance end voltage
Returns float voltage [V]
2.5 to 4.30 V
BMIN? or
BMIN x.xxx
Balancing start voltage
Returns float voltage [V]
2.5 to 4.30 V

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CMAX? or
CMAX x.xx
Cell over-voltage switch-off
Returns float voltage [V]
2.0 to 4.30 V
MAXH? or
MAXH x.xx
Over- voltage switch-off
hysteresis per cell
Returns float voltage [V]
0.005 to 2.0 V
CMIN? or
CMIN x.xxx
Cell-under voltage protection
switch-off
Returns float voltage [V]
1.8 to 4.00 V
MINH? or
MIN x.xxx
Over- voltage switch-off
hysteresis per cell
Returns float voltage [V]
0.005 to 2.0 V
CHAR? Or
CHAR x.xxx
Cell End of charging voltage
Returns float voltage [V]
2.0 to 4.30 V
CHIS? Or
CHIS x.xxx
End of charging voltage
hysteresis per cell
Returns float voltage [V]
0.005 to 2.0 V
RAZL? or
RAZL x.xx
Cells max difference
Returns float voltage [V]
0.005 to 1.0 V
TEMPERATURE SETTINGS INSTRUCTIONS
TMAX? or
TMAX x.xxx
cell over temperature switch-
off
Returns float temperature [°C]
-20 to 65 °C
TMIN? or
TMIN x.xxx
Under-temperature charging
disable
Returns float temperature [°C]
-30 to 65 °C
TBAL? or
TBAL x.xxx
BMS over-temperature
switch-off
Returns float temperature [°C]
-20 to 65 °C
BMTH? or
BMTH x.xxx
BMS over temperature
switch-off hysteresis
Returns float temperature [°C]
1 to 30 °C
CURRENT SETTINGS INSTRUCTIONS
IOFF? or
IOFF x.xxx
Current measurement zero
offset
Returns float current [A]
-2.0 to 2.0 A
IOJA? Or
IOJA x.xxx
Voltage to current coefficient
Returns float value
0.0005 to 0.5
BATTARY PACK SETTINGS INSTRUCTIONS
CYCL? or
CYCL xx
Number of full battery pack
cycles
Returns integer value
0 to 8000
CAPA? or
CAPA x.xxx
Battery pack capacity
Returns float capacity [Ah]
1.0 to 3000.0 Ah
CHEM? or
CHEM xx
Li-ion chemistry
Returns unsigned char value
1 to 5
SOC SETTINGS INSTRUCTIONS
SOCH? or
SOCH x.xxx
SOC end of charge hysteresis
Returns float value 0 –1.0
0.005 to 0.99
SOCS? or
SOCS x.xx
SOC manual re-set
Returns float value 0 –1.0
0.01 to 1.00
VICTRON COMMUNICATION SETTINGS INSTRUCTIONS
CHAC? or
CHAC x.xxx
Charge coefficient (0-3C)
Returns float value 0-3.0 (default 0.6)
0.01 to 10.0
DCHC? or
DCHC x.xxx
Discharge coefficient (0-3C)
Returns float value 0-3.0 (default 1.5)
0.01 to 10.0
STRN? or
STRN xx
Number of inverter devices
on the bus
Returns unsigned char value (default
1)
1 to 6
MAXC? or
MAXC x.xxx
Maximum charge current per
inverter device
Returns float current [A]
5.0 to 280 A
MAXD? or
MAXD x.xxx
Maximum discharge current
per inverter device
Returns float current [A]
5.0 to 280 A
CLOW? or
CLOW x.xxx
cell under-voltage discharge
protection
Returns float voltage [V]
1.8 to 4.20 V
CANF? or
CANF xx
CAN Frequency
Returns unsigned integer value
100, 125, 200, 250, 500 or 1000
100, 125, 200, 250, 500
or 1000 kbit/s

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ERROR LOG INSTRUCTIONS
ERRL?
Returns error log data (FIFO
register of the last 12 errors).
By sending the same
instruction the data pointer
shifts from the last error entry
to the first error entry, then it
starts all over again
Returns “xx,zz;
hh:mm:ss;dd.mm.yyyy”
xx-error number
zz-number of the cell/temp sensor
Read only
ERLD? or
ERLD 1
Error log delete
Returns unsigned char value. To
reset Error log set ERLD to 1 and
restart the ABMS.
0, 1
VMAX? or
VMAX xx
Number of exceeded value of
CMAX
Returns integer value
0 to 8000
VMIN? or
VMIN xx
Number of exceeded value of
CMIN
Returns integer value
0 to 8000
OUTPUTS SETTINGS INSTRUCTIONS
RE1L? or
RE1L x.xxx
Relay 1 voltage level
Returns float voltage [V]
1.8 to 4.30 V
RE1H? or
RE1H x.xxx
Relay 1 voltage level
hysteresis
Returns float voltage [V]
-2.0 to 2.0 V
OP2L? or
OP2L x.xxx
Optocoupler 2 voltage level
Returns float voltage [V]
1.8 to 4.30 V
OP2H? or
OP2H x.xxx
Optocoupler 2 voltage level
hysteresis
Returns float voltage [V]
-2.0 to 2.0 V
ABMS SETTINGS INSTRUCTIONS
CAL1? or
CAL1 x.xxx
Cell 1 calibration offset
Returns float voltage [V]
-0.025 to 0.025 V
CAL2? or
CAL2 x.xxx
Cell 2 calibration offset
Returns float voltage [V]
-0.025 to 0.025 V
CAL3? or
CAL3 x.xxx
Cell 3 calibration offset
Returns float voltage [V]
-0.025 to 0.025 V
CAL4? or
CAL4 x.xxx
Cell 4 calibration offset
Returns float voltage [V]
-0.025 to 0.025 V
SERI? or
SERI xx
ABMS Serial number
Returns unsigned integer 0 - 9999
1-9999
SWVR?
ABMS software version
Returns string v.v-dd.mm.yyyy
Read only
TIME? or
TIME xx:xx:xx
ABMS RTC Time
Returns/accepts “hh:mm:ss” format*
-
DATE? or
DATE xx.xx.xxxx
ABMS RTC DATE
Returns/accepts “dd.mm.yyy”
format*
-
WCIB?
Which cell is being balanced
Returns cell number
Read only
*BMS->Time/Date pop-up window can be used to set both values at once.
Parameter accepted and changed value is responded with 'SET' answer.
Example: proper byte message for 'LCD1?' instruction for BMS address 2 is:
<0x55><0x02><0x00><0x05><0x4C><0x43><0x44><0x31><0x3F><0x53><0x90><0xAA>
RS-485 message are executed when the microprocessor is not in interrupt routine so a timeout of 350 ms should
be set for the answer to arrive. If the timeout occurs the message should be sent again. If an array of data is sent
little endian is used for float or integer values. In case of single data is sent ASCII characters are used e.g. -1.2351e2
Custom made instructions can be added to the list to log or set the parameters that control the BMS algorithm or
its outputs.

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CAN Communication:
Figure 5: CAN female DB9 connector front view.
Table 6: CAN DB9 connector pin designator.
pin
designator
1
2
CANL + TERMINATION
3
GND
4
5
-
6
+ 5V
7
CANH + TERMINATION
8
-
9
Table 7: CAN RJ45 connector pin designator.
Pin
Designator
1
-
2
-
3
GND
4
-
5
-
6
-
7
CANH + TERMINATION*
8
CANL + TERMINATION*
* Termination plug with 120 R
No termination is used inside ABMS connector. Terminate pins 2 and 7 with 120 Ohm resistor to prevent ABMS to
reset. Additional RJ45 connector with 120 Ohms across CANL and CANH should be used for the end device on the
CAN bus for end termination.
11-bit TX identifiers: 0x351, 0x355, 0x356, 0x35A, 0x35B, 0x35E, 0x370
11-bit RX heart-beat 0x305 message from CCGX is neglected.