Bosch BAT 645 User Manual

5.4 Buffer mode
In buffer mode, the BAT 645 maintains the battery
charge if electrical equipment has to be powered with
the engine stopped. The output voltage of the BAT 645
is a smooth DC voltage and is therefore suitable for
buffering the vehicle electrical system with the vehicle
battery.
! When operating an LFP battery in buffer mode,
the instructions of the battery manufacturer must
be observed when entering the parameters (see
sec.6.1.1).
1. Connect the BAT 645 to the mains voltage system
via the power supply cable.
2. Connect the red charging clip to the battery
positive terminal (+).
3. Connect the black charging clip to the battery
negative terminal (–).
4. Switch on the BAT 645 by way of the on/off switch
(fig.1, item1).
 The red LED (fig.1, item7) lights up.
 The battery voltage is displayed (for four sec-
onds) then the "Mode" menu appears.
5. Select "Buffer mode" with
or .
6. Press
.
 Yellow LED lights up (fig. 1, item 9).
 The battery is buffered after detection of the bat-
tery voltage (at least 9V for 12-V batteries and
18V for 24-V batteries).
Fig. 5: Buffer mode
1 Voltage and current actual values
2 Information on the selected mode, charging cable length and
parameter settings
i The parameter settings are selected in the
"Configuration >> Parameter" menu (see sec.6.1).
7. Buffer mode is stopped with
.
 The yellow LED is off.
 The "Mode" menu is displayed.
8. Switch off the BAT 645 on completion of buffer
mode.
9. Remove the charging clips from the battery.
5.5 Back-up mode
In back-up mode, the BAT 645 can power the electrical
equipment in a vehicle instead of a battery. Back-up
mode can be used for example to maintain a supply
of power to the electrical equipment in a car when
changing a battery. The output voltage of the BAT 645 is
a smooth DC voltage and is therefore suitable for back-
up of the vehicle electrical system even without a vehicle
battery.
1. Connect the BAT 645 to the mains voltage system
via the power supply cable.
2. Connect the red charging clip to the positive
terminal clamp or, if present, the positive
connection for starting assistance.
3. Connect the black charging clip to the negative
terminal clamp or the body.
4. Switch on the BAT 645 via the on/off switch (fig.1,
item1).
 The red LED (fig.1, item7) lights up.
 The battery voltage is displayed (for four seconds)
then the "Mode" menu appears.
5. Select "Back-up mode" with
or .
6. Press
.
 Yellow LED flashes (fig. 1, item 9).
 The vehicle voltage is supported after detection
of a battery voltage (at least 3V for 12-V batter-
ies and 17V for 24-V batteries).
 The vehicle battery can be changed.
Fig. 6: Back-up mode
1 Voltage and current actual values
2 Information on the selected mode, charging cable length and
parameter settings
! When reinstalling the battery, it is important that the
battery clamps are connected to the right poles as
otherwise this could damage the BAT 645.
i The parameter settings are selected in the
"Configuration >> Parameter" menu (see sec.6.1).
7. Back-up mode is stopped with
.
 The yellow LED is off.
 The "Modes" menu is displayed.
8. Switch off the BAT 645 on completion of back-up
mode.
9. Remove the charging clips from the battery.
| 20 | BAT 645 | Operationen
1 689 989 233 2022-01-24| Robert Bosch GmbH

Bosch BAT 645 Specifications

General

Brand	Bosch
Model	BAT 645
Category	Battery Charger
Language	English