I+ME ACTIA BMS Master 4, Hardware Manual, Page: 48 / 76

Hardware Manual
BMS Master 4 / 4.5
Ref.: IR14417 A 15.01.2018 Page 48/76

to MASTER
3.5.4.7 2
ND
-L
EVEL
O
VERVOLTAGE
D
ETECTION
Every single cell voltage is supervised by a “second level security chip”, activating the
FAIL-output if only one cell voltage exceeds 4.4 V for more than one second (other threshold
voltages are possible, but the realization depends on quantity.
This circuitry is always active and cannot be deactivated, though it is possible to activate it by
software for test reasons.
3.5.4.8 L
ONG
T
IME
W
ATCHDOG
A slow RC-oscillator with ca. 3 Hz clocks a multistage counter which has to be reset by the
master periodically. If the counter will not be resetted, all balancing resistors are cut off after
ca. 40 minutes to prevent a total discharge of the cells.
3.5.4.9 C
ONFIGURATION
- A
DDRESSING
To assign each SLAVE_5 a unique address number in a system a „capture/compare”-
processor-port is used. Each SLAVE_5 in a system must have an own address number for the
master to be allocated.
While being configured the slave has to be supplied via the configuration-interface and must
not be connected to battery cell voltages. Slave configuration must be done using configurator
SC-CONFIG2, a proper interface cable belongs to the configurator. Configuration data are
stored in the serial E²ROM.
Using accordant PC-software E
2
ROM data and thus the module address may be altered via the
2nd serial port.
The configuration interface uses 6 pins of the 24-pole connector; pins 10, 11, 12, 22, 23, 24
(see Chap. 3.5.3).
Using this connector as configuration interface, all other pins (1…9 und 13…21) must not be
used.
3.5.5. C
ONNECTING
E
XTERNAL
B
ALANCE
R
ESISTORS
External balance resistors may be mounted and connected directly at the cell contacts in
conjunction with an additional cable to the 22-pole connector. The cell voltage sense lines in
the 24-pole connector (see chap.3.5.3) are not affected.
Special care has to be taken on correct mounting and connecting the resistors to the cells,
as depending on cell number they have to be attached either to cathode or anode.
The resistor value must not be lower than 8.2 Ω, power rating must be greater than 2.5 W,
heat dissipation has to be adequate.
Together with the piggyback balance board a current of ~ 570 mA will be achieved with