JLG X20JP - X600AJ Service Manual - Manual (Page 134)

SECTION 3 - CHASSIS & TURNTABLE
3-110 – JLG Lift – 3121623
Principle of functioning
Hydraulically the lithium platforms operate exactly as the
other dual -power source models (thermic engine+
electrical motor), but have one power source only.
The power source consisting in a DC electric motor 48 or
72 Volt three phases, that run a tandem dual gear pump.
An inverter manages the speed of the electric motor to
obtain the accurate oil flow from the pumps.
A Lithium battery pack 48 or 72 Volt (it depend of the model)
feed the inverter, which supply the electrical motor a Direct
Current.
To verify, calibrate and manage the current coming from the
battery pack to the electrical motor, there is an additional
ECM module, called BMS (Battery Management System).
The BMS checks, calibrates and manages the current going
inside-outside the battery pack.
The ECM’s boards 1-2 -3 (and 4 if present) of the lithium
platform are the same of all other CCB models, and as
usual are feed with 12 Volt DC, while also the BMS require
the same voltage . A lead 12 Volt battery is fit on the
machine and provide to feed the ECM’s and the BMS.
To keep charged the lead battery, in the battery pack there
is a DC-DC (=Direct current-Direct current), that is an
electric transformer able to convert the 48 or 72 DC volt of
the battery pack, to 12 Volts DC.
According with the life cycle of a lead battery, the voltage
level can drop in the years; if the lead battery voltage is too
low or the lead battery is flat, it is not possible to turn on the
machine ECMs, BMS included.
The Lithium battery pack consist of 15 (if 48 Volt) or 22 (if 72
Volt) cells.
To recharge the cells a specific battery charger is present in
the battery pack. This battery charger receives the power
from the wall socket network (110/ 120/220 Volt AC) and
supply 48 or 72 Volt DC to the cells.
The Lithium Battery charger adapts the current supplied to
the battery cells, as required by the BMS.
With the Key to OFF, the battery pack is completely dis-
connected for safety reasons, furthermore also all the
ECMs are OFF in order to avoid electric energy consump-
tion.