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3.2. Battery
system
Li-ion battery is made of:
An assembly of Li-ion modules connected in series.
A Battery Management Module (BMM) which is the interface between battery and
customer application.
An external power supply (24V) is needed to supply the BMM (see §2.1 for characteristics).
3.2.1. Li-ion Modules
Li-ion modules contain 14 cells connected in series.
A 200A fuse protects the module against short-circuit (
fuse not replaceable
).
Each module contains an electronic board (named SMU) which monitors and sends the
following information to the BMM:
1 temperature measurement
14 cell voltages measurement
1 emergency signal (digital line) driven by redundant hardware channel. This signal is
active in case of:
Cell over charge
Cell over discharge
Module over temperature
Module switched OFF
The electronic board manages also the cells balancing and the data timestamp.
3.2.2. BMM
The Battery Management Module (BMM) optimizes the battery performances and protects the
battery against extreme situations (over charge, over discharge, over temperature). The BMM
monitors all modules and communicates with the customer application to manage battery cycles
(charge and discharge).
The BMM functions are:
Management of SMU boards (calculation of the data from the modules)
Measurement of the battery current
Battery over current protection (by 50A fuse)
Protection of the battery unit
Communication with the EMS via CAN Open bus
Diagnostic functions using a RS485 bus