User Manual
current. This function is used to compensate for the use of long or thin wire between the
Input Battery System and the unit input terminals. If the input voltage continues to drop
below the <10.5V for a 12V system (<21V for a 24V system), the charging process will terminate
and the unit will switch back to charge from CH2 (solar if installed) if installed. It will only
switch back to CH3 if the CH3 voltage is >13.2V on a 12V system (>26.4V on a 24V system.
Note B:
When the unit has activated the battery charging process using the ignition sense terminal
(Priority Mode) or using the Manual Override through the unit setting, the input voltage
specication is reduced. It has the same charging process but with a Low Start-Up Voltage
set to >12.3Vdc 12V system (>24.6V on a 24V system). This feature is designed to be used for
vehicles tted with “Smart Alternators”.
If the measured voltage on CH3 is <12.0 Vdc (<24Vdc on a 24V system), the unit will disconnect
from the vehicle source and switch back to charge from CH2 (solar if installed) until the CH3
voltage returns to >12.3Vdc on a 12V System (>24.6V on a 24V system).
The Low Under Voltage Recovery Voltage is set to > 12V (from 12.8V) on a 12V system and
> 24V (from 26.4V) on a 24V system. During the 5 second rest period, if the input voltage
returns above 12V/24V, it will continue the charging process and if the input voltage does
not return to > 12V/24V, it will switch back to charge from the Solar - CH2 (if connected) until
the Start - CH3 input has returned to the Low Start-Up voltage of 12.3V on a 12V system and
24.6V on a 24V system.
Note C:
During the 3 minute charging process, if the measured terminal voltage drops below the
Under Voltage de-rated limit (11.5V for a 12V system, 23V for a 24V system), the charger will
start to de-rate the charger current. This function is used to compensate the use of long
or thin cable between the Input Battery and the unit terminals. If the voltage continues to
drop to below the Under Voltage Shutdown limit of (10.5V for a 12V system and 21V for a
24V system), the charging process will terminate and the unit will switch back to charge from
CH2 (solar if installed). It will only switch back to CH3 if the CH3 voltage returns to 13.2V
(12.3v with ignition sense connected) on a 12V system and 26.4V (24.6V with ignition sense
connected) on a 24V system.
Note D:
The CH3 DC Input (Battery Input) can accept a 12V or 24V battery with an alternator system.
When the unit is rst connected, the unit will measure the input voltage. If the voltage is
>17V, it will assume it is connected to a 24V Input Battery/Alternator system. If the voltage
detect is < 17V, it will assume it is connected to a 12V Input Battery/Alternator system. Once
detected, it will store this into the microprocessor and it will only be erased if the Input
battery is disconnected or if the measured Input Voltage drops to < 7Vdc.
7. UNIT OPERATION
Understanding The Charging Mechanism
Note 1: The Charger is powered by the battery connected to DC Output (CH1) and also
supplied by CH2 or CH3 if available. The display will turn o to save power when Input
Channel CH2 and CH3 are out of operating range.
Operating from a Start Battery / Alternator (CH3)
Normal Operation:
Input Battery / Source
12V Input 24V Input
Input Voltage Range 10.5V – 16.0V 21.0– 32.0V
Normal Start-Up Voltage (Note A) > 13.2V > 26.4V
Normal Under Voltage Recovery Voltage (Note A) > 12.8V > 25.6V
Ignition Sense Terminal
Ignition Sense Terminal must see
a minimum of 10.5V to trigger low
voltage “Priority Mode”.
Low Start-Up Voltage (using Ignition Sense Terminal or
using Manual Over-ride setting) (Note B)
> 12.3V > 24.6V
Low Under Voltage Recovery Voltage (Note B) > 12.0V > 24.0V
De-Rated Voltage (with load) (Note C) 11. 5 V 23.0V
Under Voltage Shutdown (with load) 10.5V 21.0V
Over Voltage Shutdown 16.0V 32.0V
Over Voltage Recovery 15.5V 31.0V
Input Battery System Reset Voltage (NoteD) < 7V < 7V
Maximum Input Current - EN3DC30-24 30A 30A
Note A:
When the battery is charging through CH3 with normal operation (not through Ignition
or override setting), the charger will charge for 3 minutes, it will then rest for 5 seconds to
verify the Input voltage.
During the 5 seconds rest period, if the measured voltage is >12.8Vdc on a 12V System
(>25.6Vdc on a 24V system), the unit will continue the charging cycle through CH3.
If the measured voltage on CH3 is <12.8Vdc (<25.6Vdc on a 24V system), the unit will
disconnect from the vehicle source and switch back to charge from CH2 (solar if installed)
until the CH3 voltage returns to >13.2Vdc on a 12V System (>26.4V on a 24V system).
Also, during the 3 minutes charging process, if the measured terminal voltage drops below
<11.5V for a 12V system, (<23V for a 24V system), the charger will start to derate the output
Enerdrive ePOWER DC2DC 24V Battery Charger Owners Manual (Rev. 1.5) www.enerdrive.com.auPage 20 Page 21