Manual EM-box 3
Hardware 3.1 - REV 3B - JAN 20
Page 18
5.
Operation EM-box
5.1 Charge division
The EM-box controls the charging voltage of the alternator via its voltage sensor connection, the so-called sense
input. If this is not available, it should be retrofitted by a specialist company in order to obtain optimum charge control
if possible.
The three-step charge control takes into account:
- Battery type (wet, gel, AGM, lithium)
- Battery temperatures (in the range of -20°C...+50°C to determine the gassing voltage with 14.4 V at 20°C or 28.8 V
and its correction with 18...36 mV/°C or 36...72 mV/°C)
- Battery charging currents 0.5%C...2%C (to determine the switchover time to trickle charge)
- Time of the battery charging phases (2h...16h, for safety shutdown or according to the specifications of the battery
manufacturer for charging)
- The EM-box distributes the charging current (max. 250 A) low-loss to the three independent battery groups and
regulates the offered voltage according to the respective state of charge of the battery group.
The charge current distribution is sequential. This means that the battery groups to be charged are switched on for
charging depending on their state of charge and disconnected also from the charging process again in order to enable
the batteries to be fully charged via the alternator with a sufficiently long alternator running time and to prevent
overcharging. While the individual battery groups are being charged, the charging current can be temporarily
suspended by the charging program in order to charge the other battery groups optimally according to the set battery
type.
5.2 Voltage and current measurement
At all 8 positive power bolts and the charge inputs AUX1/2, the current is measured individually and made available to
the PSM system monitor for display. The voltage measurement is performed for the starter, service and bow battery.
The current and voltage values are used to calculate the capacity for the 2 nd starter and service battery groups.
When the battery disconnector are switched off the EM-box goes into a power saving mode, the current and voltage
measurement and the resulting capacity calculation remains active.
5.3 Battery disconnect switchs
A battery disconnect switch is available for the starter battery and the service battery. These can be switched via the
control lines and via the P bus (CAN bus). Manual operation of the main switches directly on the EM-box is also
possible in emergencies,
A third main switch can be activated for EMERGENCY START of the engine via the service battery, which is switched
via the control lines or via the philippi P-Bus.
5.3.1
Emergency start
If the starter battery is empty, the engine cannot be started. In this case, the engine (starter motor) can be supplied via
the consumer battery by activating the emergency start function. For this purpose, the starter connection is switched
internally from the starter battery to the consumer battery. The charging functionality is not affected by this.
5.3.2
Manual switching of the battery disconnect switch
In the event of a failure of the electronics of the EM-box or in a emergency case the main switches can be operated
directly on the EM-box.
Important: Manual operation of the button is not indicated by the status LED. After a manual operation of the
main switch an electrical operation must be carried out as soon as possible.
5.3.3
Control of the battery disconnect switch
In order to enable control via the system monitor even when the main switches are switched off, its power supply must
be connected to the continuous positive output of the EM-box.
In principle, the battery main switches must be controlled via the control lines on terminal X2, in order to be able to
switch the main switches in an emergency (e.g. in case of CAN bus failure).
