User manual
23
© 2009, Elektro-Automatik GmbH & Co. KG
EN
Functional description
Note: below names given in blue are adjustable in the
battery proles.
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 denes 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 dened 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