6
NOTE: for a detailed explanation of the charging modes, please refer to our publication Theory
of Operation, document #AD-TD-0001-0.
BULK MODE
If the output current reaches its maximum (normally caused by a discharged battery), this will
cause the converter to go into Bulk Mode, which means the target output voltage will change
to 14.4 VDC and a timer will start. Although the converter is outputting 14.4 VDC, you will not
be able to read that on a voltmeter due to the voltage-current relationship. From the paragraph
above, as load current increases, output voltage decreases. The actual output voltage will not
rise until the load current is reduced, which happens naturally as the battery charges or if 12 VDC
appliances are turned off.
Bulk Mode will be maintained until the current draw drops to approximately five Amps, or until
the timer reaches four hours (whichever happens first). Then the target output voltage is changed
back to 13.6 VDC for Absorption Mode. Lights that are powered from the output may change
brightness slightly at that time.
FLOAT MODE
The third mode of charging is what is called the “float” charge. This mode is designed to
provide a “trickle charge” to the battery after the system observes no significant variations in
current draw over a long period of time. When in “float” mode, the voltage will reduce from
13.6V to 13.2V and supply the “trickle charge” which helps to preserve the life of the battery
while keeping it charged and r
eady for use. A change in DC current will cause the converter to exit the mode and return to the
Absorption mode and then to Bulk mode if required.
Note:
For a detailed explanation of the charging modes, please refer to our publication “Theory
of Operation”, document #AD-TD-0001-0.
LITHIUM TWO-STAGE SMART CHARGING
The two-stage “smart” charger continuously measures the battery voltage output and regulates
the amount of charge using two modes of operation: Bulk and Absorption mode.
2-STAGE CONVERTER VOLTAGE OUTPUT MODES
Understanding output voltages of a two-stage converter.
Figure 2
