p/n 725.0001 REV 3.0
© 2023 TCW Technologies, LLC.
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General Product Information:
The Charging System:
The IBBS automatically maintains its internal battery pack. The internal charging circuit monitors
the state of the internal battery and recharges the battery as necessary when the aircraft is
operational. The input current for battery recharging is nominally 3.3 amps. Battery charging only
occurs when the aircraft supply bus connected to pin 5 is above 13.7 volts. (charging only occurs
when the aircraft alternator is running and has available capacity)
If the internal battery is fully discharged for any reason it may require up to 120 minutes of
recharge time with the normal aircraft bus on. NOTE: Do not attempt to recharge the IBBS
product by using an external lead-acid type battery charger directly connected to the input of the
IBBS. Battery chargers typically provide pulsating voltages that may damage the IBBS product if
the system is not connected to a typical primary aircraft battery. Also note, you cannot use a
DMM connected to pins 4,5 to measure any meaningful value. Battery voltage may be read on pin
2 or any of the outputs pins 12-15 with the IBBS system enabled via the grounding of pin 1. Note:
recharging of battery is linear with respect to time. For example, under nominal conditions a
recharge period of 1 hour will provide 1/2 of rated product capacity.
Recharge time at normal temperatures: 0C° to 40 C° 120 minutes nominal
Recharge time at low temperatures: -18C° to 0 C° n 15 minutes preheat
-45 C° to -18C° n 60 minutes preheat
Back-up Power Master Switch:
The IBBS has one input switch connection as identified in the wiring diagrams: Back-up Power
Master. This switch enables back-up power from the IBBS system to be available on the output
wires when power on the normal aircraft bus falls below 11 volts. Pin 1 is pulled to ground when
the back-up master switch is turned on, this enables the IBBS system.
If the back-up power master switch is enabled and normal aircraft power falls below 11 volts then
the internal back-up battery will be connected to the outputs and be utilized to supply back-up
power to the connected load.
If the normal aircraft power bus is above 11 volts, then the outputs are energized with normal
aircraft power (if the pass thru-power connections are utilized) and the back-up battery remains off-
line. The pass thru power feature does NOT depend on the state of the back-up master switch. If
power is made available on the pass-thru power inputs, it will pass through and be available on the
outputs. This allows for automatic pass through of power during normal operation.
Ground Based Recharging:
To accomplish ground-based charging, connect an approved battery charger or DC power source
(set to 14 volts) to the main aircraft battery and energize the main aircraft power bus by turning on
the master switch, leave all other aircraft loads in their off state. Note, the ground base source of
power must be capable to supply the load current of all devices that can not be turned off in this
nominal state, plus the 3.3 amps of IBBS recharge current. Leave the ground-based charging
system connected and powered until the IBBS system completes its recharge cycle of its internal
battery. See above for details on battery charging time. If voltage monitoring of pin 2 of the IBBS
is available a peak charging voltage of 14-15 volts will be observed as the battery reaches full
capacity.
