13
4 FREQUENTLY
ASKED
QUESTIONS
Q
The BCDC Dual Input turns ON at 13.2V(12V) and OFF at 12.7V(11.9V), but you say it operates
down to 9V, explain?
A
The BCDC Dual Input will turn OFF for a split second every 100 seconds to measure the unloaded
voltage at the battery. When the BCDC Dual Input turns off it is not drawing any load from the start
battery, no load means that there is no voltage drop over the cable run. This allows the BCDC Dual
Input to measure the actual battery voltage, or the voltage at the battery. If this actual battery voltage
is below 12.7V(11.9V), the BCDC Dual Input
will turn OFF. At any other time during the charging
process, if the voltage at the BCDC Dual Input drops below 9V the BCDC Dual Input will turn OFF.
Q
How does the BCDC Dual Input charge an Auxiliary battery at 14V when it only gets 9V in?
A
The BCDC Dual Input can act as both a reducer and a booster, so it can operate from a voltage
of above, equal to or below the desired output voltage. The unit is also microprocessor controlled
allowing it to output a Redarc proprietary charging algorithm independent of the input. This allows
the unit to charge specifi c to the battery type even if the input voltage is low due to voltage drop.
Q
Where should I mount the BCDC Dual Input Unit?
A
The BCDC Dual Input should be mounted as close as possible to the battery being charged (generally
called the Auxiliary or House battery). If the Auxiliary battery is located under the bonnet, pick a
location for the BCDC Dual Input that is close to the battery and away from any direct engine heat. If
the BCDC Dual Input is to be mounted into a Caravan or Camper, near or in the battery compartment
is generally the best position. It is also a good idea to mount the BCDC Dual Input to a metal surface
if possible to ensure optimal heat dissipation, though this is not crucial.
Q
What does the charger do if the temperature around it rises above its operating temperature?
A
As the temperature of the BCDC Dual Input rises above a certain level the current capacity of the
output is decreased gradually in order protect both the battery and the BCDC Dual Input unit.
Q
If I use the BCDC Dual Input to charge my auxiliary battery do I still need to install a battery
isolator?
A
The BCDC Dual Input incorporates the functionality of a battery isolator, it will turn ON and start
charging when it senses that the vehicle has started and similarly it will turn OFF when the vehicle is
turned OFF.
Q
I’ve heard that you shouldn’t charge 2 batteries of different chemistries from the same source,
will I have any problems charging my AGM or Gel auxiliary battery from my Lead Acid start
battery?
A
The BCDC Dual Input does not ‘link’ the batteries together like a battery isolator does, it is a DC-DC
battery charger. The output from the unit is tailored specifi cally to the selected output battery type,
and therefore allows the optimal charging of the auxiliary battery, no matter what chemistry your
start battery is.
Q
My BCDC Dual Input is setup for 12V Alternator input but will not start when the vehicle is turned
On, I’ve followed the trouble shooting guide and the setup is fi ne, what’s the problem?
A
The most likely cause of this issue is that the BCDC Dual Input is somehow ‘stuck’ in 24V mode.
Try removing the ‘Vehicle’ (RED) wire and reconnecting it. If the problem still exists please contact
Redarc Electronics.
Q
Can the BCDC Dual Input charge from Solar and Vehicle power at the same time?
A
Yes. The BCDC Dual Input will always attempt to supply power from the Solar source fi rst (when
available) and will supplement this input with power from the Vehicle source (when available).
