Product Function | 9
1.4 Charging Process
BOOST
When the Charger is turned on, it will begin in the Boost stage. The Boost stage maintains a
constant current until the battery voltage reaches its Absorption Voltage. The current in Boost stage
may vary during operation in order to maintain safe operating temperature, or to limit the difference
between input and output voltages.
ABSORPTION
The Charger will then move to Absorption stage which maintains a constant voltage level for a
predetermined period of time or until the current being drawn by the output battery drops to less
than 4 A for 30 seconds; after which the Charger will enter Float stage.
FLOAT
Float stage maintains 13.3 V (13.6 V for LiFePO
4
) on the output battery, keeping the battery topped
up. This counteracts the battery’s self discharging or loads applied to the battery. When the battery
loses charge, the Charger will move back into the Boost stage.
Figure 1.4.3.1:
Charging Process for BCDC1225D and BCDC1240D
Voltage
Float
Absorption
Boost
Current
The BCDC has automatic timeouts to protect the battery from being damaged by overcharging.
The BCDC will automatically move from Boost to Absorption or Float according to these
timeouts. If a timeout occurs before the battery is fully charged, the charge process will begin
again from the Boost stage after the 'rest-period'. The Li profile timeouts have been adapted to
suit optimal charging for large lithium battery banks.
