BATTERY MANAGEMENT SYSTEM
5/2015
The RIMAC AUTOMOBILI BATTERY MAN-
AGEMENT SYSTEM (R-BMS) is a full solution
for monitoring and controlling of complex battery
systems for various applications.
The latest R-BMS is our fifth generation system,
where we have implemented new functionalities
and all our experience gathered during the im-
plementation of high-power battery systems in
extremely demanding applications ranging
from electric supercars to boats, bicycles and
wheelchairs.
The system is primarily designed for electric ve-
hicles but is also used in various applications
such as hybrid vehicles, battery test-benches
and dyno systems.
The newest R-BMS generation features ex-
tremely compact dimensions, ultra-low
power consumption, very high measure-
ment accuracy and fast refresh rates.
R-BMSFUNCTIONALITIES
OVERVIEW
COMPLETE BATTERY MANAGEMENT SOLUTION
CELL MONITORING
TEMPERATURE MONITORING
ABILITY TO CONTROL SEVERAL EXTERNAL DEVICES
SYSTEMS FOR RETAINING MAXIMUM BATTERY LIFETIME
STATE OF HEALTH ESTIMATION
CELL BALANCING
STATE OF CHARGE ESTIMATION
THE R-BMS CONSISTS OF:
• BMS SLAVE UNIT(S)
• BMS MASTER UNIT
OVERVIEW
BMS SLAVE UNIT(S)
BATTERY PACK
POWER DISTRIBUTION UNIT
COMMUNICATION AND SIGNAL LINE
HIGH VOLTAGE
BMS MASTER UNIT
The R-BMS consists of one or more dis-
tributed R-BMS Slave devices, which
can monitor and balance a series from 3 up
to 12 battery cells.
Several R-BMS Slave devices can be used
in a battery pack or module, being able to
supervise a complete HV battery ranging
from 6V, up to 1000V.
R-BMS Slave devices have no power con-
sumption from the monitored cells while
the system is not active or the vehicle is
off. This feature ELIMINATES “VAMPIRE
LOADS” that are common with traditional
BMS systems, which can cause the bat-
tery to discharge completely and perma-
nently damage the cells. There is no need
to charge the battery in case the vehicle is
not being used for a longer period of time.
During the normal operation, power con-
sumption is less than 5mA per cell.
R-BMS SLAVE BMS SLAVE UNIT FUNCTIONAL OVERVIEW
CELLS
CELLTEMPERATURE
TEMPERATUREMEASUREMENT
PCBTEMPERATURE
BALANCING MODULE
CELLMEASUREMENT MICROCONTROLLER
ISOLATEDPART
COMMUNICATIONMODULE
INSULATION
BMS SLAVE SMART SLAVES
CAN OR FO
The R-BMS slaves are supervised by
the R-BMS Master unit.
The R-BMS system is capable of supervis-
ing all types of available battery chemis-
tries. Flexible hardware design allows the
system to measure single cell voltage in
a range from 0V to 5V with measurement
accuracy of 1mV. The measurement accu-
racy is consistent for the whole battery for
voltages up to 1000V. Furthermore, each
R-BMS slave measures 2 cell tempera-
tures and 2 PCB temperatures allowing it
to supervise the temperature throughout
the whole battery pack. Each R-BMS slave
device is equipped with passive resistive
balancing that can balance overcharged
cells with the current of 1A.
By using very precise measurements and
implementing smart balancing algorithms
the R-BMS has shortened needed bal-
ancing several times.
Collected R-BMS slave data is constantly
distributed through the high speed CAN
network with transmit period of 50ms, mak-
ing the data available on other devices 20
times per second. Due to the fast refresh
rate, it is possible to implement SMART
CONTROL ALGORITHMS which maxi-
mize cell usage while retaining maxi-
mum lifetime. In applications with the
high EMC noise, the R-BMS can be used
with the Fiber Optic communication in-
stead of CAN, making it entirely immune to
the EMC noise.
OPTIMISED BATTERY USAGE AND LIFETIME
R-BMS SLAVE
117 mm
102
mm
R-BMS SLAVESPECIFICATIONS
The R-BMS Master device is the central
unit supervising and controlling the
whole battery pack.
It is capable of calculating very accurate
State of Charge (SoC) and State of
Health (SoH) of the battery pack. Some
of the used cell chemistries have a very flat
voltage curve throughout most of the SoC
making it impossible to determine (or even
estimate) the SOC based on the cell-volt-
age alone. Therefore a very accurate SOC
calculation is needed, as well as a very ef-
fective balancing method.
In order to achieve a very high accuracy
of SOC and energy consumption estima-
tion, the R-BMS system uses a MORE
SOPHISTICATED METHOD than the
industry-standard single-current-sensor
set-up. Each high-voltage system can be
monitored individually through separate
energy measuring channels.
R-BMS MASTERBATTERY SUPERVISION AND CONTROL
CURRENT SENSORS CURRENT SENSORS
HIGH-SIDESWITCHES(6A)
HALF-BRIDGESWITCHES(4A)
MICROCONTROLLERDIGITALINPUTS
MASTER
The R-BMS Master system is capable
of controlling (supplying power to)
several external devices through the in-
telligent high-side drivers. All of those driv-
ers are equipped with several protections
and are capable of DETECTING AND
PREVENTING the overcurrent, overvolt-
age, overtemperature and reverse polarity
conditions. The high-side drivers are usu-
ally used to control several high-voltage
relays.
The R-BMS Master system can be used
either as a stand-alone unit or fully con-
trolled through different communica-
tion protocols. If configured to work as a
stand-alone unit, the R-BMS system can
control the pre-charge of several high-
voltage devices. It is also capable of
monitoring the status of each high-voltage
relay and able to detect the welded state
or the state in which the relay will not close.
The R-BMS system is equipped with sev-
eral CAN, Fiber Optic, RS232 and RS485
communication lines that can be used
to distribute the collected and calcu-
lated data. The R-BMS system is also
equipped with the bootloader capabil-
ity, making it possible to fully program and
configure any R-BMS device without the
need to directly access them.
R-BMS MASTER
CONTROL AND COMMUNICATION
291 mm
128
mm
R-BMS MASTERSPECIFICATIONS
R-BMS & INFOTAINMENTEASIER INTEGRATION FOR FASTER DEVELOPMENT
During the development and testing
phase of the project it is desirable to
show as much system data as possi-
ble on the vehicle In-Vehicle Infotainments
system.
With the R-BMS system this is easily done
as the system sends all cell-voltages, tem-
peratures and currents to the In-Vehicle
Infotainment which displays all data in real-
time. This gives the development engineers
a very good overview of the behavior of all
systems.
As most of those values are not relevant
to the end-user, once the development is
completed, only a summary of values such
as the SOC and battery-temperature is
available to the user.
RIMAC AUTOMOBILI
CONTACT:
MARKO PEJKOVICBusiness Development Manager
tel. +385 91 333 [email protected]