JLG X20JP - X600AJ Service Manual - Manual (Page 138)

SECTION 3 - CHASSIS & TURNTABLE
3-114 – JLG Lift – 3121623
BMS (Battery Management System)
The Battery Management System (BMS) is the electronic
device which constantly monitors the state of the LiFePO
4
cells and grants their optimal functioning. It is composed
by different electronic boards assembled together, as
illustrated in the picture below.
BMS is continuously monitoring the cells, managing
charge and discharge of the battery pack during the
machine work.
Switching on the machine, the ECM1-2 switches on the
BMS.
Connecting the network socket to charge the cells with
the machine off, the battery charger is switching on the
BMS.
DISCHARGE OPERATION
Using the machine all the cells are discharged together
because they are connected in series. BMS monitors con-
tinuously the total voltage level and send this value in the
CAN BUS line. The operator can read it on the display.
As soon as the voltage level reach 20% or less, the remote
control starts to beep in order to inform the operator pack
level is low; if the voltage level reach 10% or less, BMS
inform the inverter (CAN BUS line) and the current request
is reduced in order to move the machine very slowly and
force the operator to connect the network cable before the
complete discharge.
However the complete discharge is not 100% discharge
for the battery pack. It means that even if the operator is
using machine till the complete discharge (machine stop),
cells cannot get damaged because of excessive low volt-
age.
Power board
Control board
Monitoring board 1
Monitoring board 2
J1
J2 J3
J4
J5
Figure 3-44.