Frequently Asked Questions | 21
4 FREQUENTLY ASKED QUESTIONS
The BCDC Dual Input turns ON at 12.9 V (12 V) and OFF at 12.7 V (11.9 V), but you say it
operates down to 9 V, please explain?
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 12.7 V (11.9 V), 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 9 V, the BCDC Dual Input will
turn OFF.
How does the BCDC Dual Input charge an Auxiliary battery at 14 V when it
only gets 9 V in?
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 specific to the battery type even if the input voltage is low due to voltage drop.
Where should I mount the BCDC Dual Input Unit?
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.
What does the charger do if the temperature around it rises above its operating
temperature?
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.
If I use the BCDC Dual Input to charge my auxiliary battery do I still need to install a
battery isolator?
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.
