User manual

25
© 2009, Elektro-Automatik GmbH & Co. KG
EN
Functional description
III. Lead batteries
The charging procedure for lead batteries follows an
I-U-U characteristics without automatic stop when the
battery is fully charged. Also see gure below.
During the precharge phase the battery is charged with
reduced output current I
PC
. After the charging voltage
has risen to U
PC,END
or time t
PC,END
is exceeded
,
the de-
vice changes to boost charge with constant current
I
CHARGE
. During the boost charge the battery voltage will
continuously rise.
After the charging voltage has risen further to U
CHARGE
or after a max. phase time t
CC,END
, the device changes
to normal charge. This will charge the battery with
constant voltage until the charging current sinks below
the threshold I
A
. Then the charger will change to the last
charging phase, the trickle charge. This phase runs
with charging voltage U
TRICKLE
until manually stopped
and keeps the battery permanently charged.
A cell supervision for the precharge phase can be
activated in the battery prole (also see „Menu: Bat-
tery prole“). This feature supervises battery voltage
changes. If the battery voltage increase is lower than
∆U/∆t, the charging will be aborted and the battery is
considered as defective.
During the entire charging procedure the battery tempe-
rature can be supervised by the temperature sensor (if
connected). The charging voltages of normal and trickle
charge phases are then compensated depending on
the battery temperature.
It is always advised to charge with temperature com-
pensation. If the temperature sensor is not connected,
the charging voltages will be set as dened in the
battery prole(s).
Temperature sensor
It is recommended to use temperature compensation
when charging batteries, in order to prevent dangerous
gassing. Without the temperature sensor the batteries
are charged with the dened charging phase voltages
in the battery prole, which correspond to an ambient
temperature of 25°C. Lithium batteries are not tempe-
rature compensated. Here the sensor just serves for
temperature supervision.
The sensor is directly connected to pins 1 and 6 of
the analogue interface and has to be attached to the
battery body. If the use of a temperature sensor has
been activated in the battery prole, it is detected and
used when the charging is started.
Figure 3. Charging characteristics for lead batteries