User manual

23
© 2009, Elektro-Automatik GmbH & Co. KG
EN
Functional description
Note: below names given in blue are adjustable in the
battery proles.
Charging procedures
Attention! Defective batteries (U
Bat
< U
Min
) must not
be charged!
I. Lithium batteries
The charging procedure for Lithium batteries follows an
I-U characteristics with automatic stop when the battery
is fully charged. Also see gure below.
The rst charging phase is a precharge phase with
reduced output current I
PC
. The precharge is very ef-
fective for heavily discharged batteries, providing the
possibility to prepare them gently for the charging.
After the charging voltage has risen to U
PC,END
or after a
max. phase time t
PC,END
,
the device changes to normal
charge.
During normal charge, the charging level of the bat-
tery denes the charging current, which can be max.
I
CHARGE
. During the constant current charge the battery
voltage will rise and if it reaches U
CHARGE
, the charging
continues with constant voltage until the charging cur-
rent sinks below the threshold I
A
. After this the battery
is considered as fully charged and the charging stops
automatically. If time t
A
has elapsed before the charging
current has decreased below I
A
, then the charging will
be aborted and the battery is possibly not fully charged.
This can happen if wrong charging parameters have
been dened or if the battery is defective.
Attention! There is no temperature compensation
for Lithium batteries. The battery temperature is su-
pervised for over- or undertemperature, though.
Functional description
Figure 1. Charging characteristics for Lithium batteries