Two-Stage Charging - Xantrex TC1012 Owner's Manual

Operation

Two-Stage Charging

The two-stage charging mode employs the following
sequence: Bulk and Absorption. It runs similar to the three-
stage sequence except that there is no float stage; after the
absorption stage the charger stops providing current to the
battery and the charger output drops to 9 V (12 Vdc chargers)
or 18V (24 Vdc chargers). In this manner, DC loads draw
power supplied by batteries and the charger enters a "rest or
standby stage." Like the three-stage sequence, the charger
will restart the charging cycle in the Bulk stage if the lowest
battery voltage of the three banks drops below 12.5 V
(12 Vdc chargers) or 25 V (24 Vdc chargers) for 15 minutes.
After 21 days, the charger will automatically restart charging
in order to refresh the batteries.
Battery Voltage
Vgas voltage
Charge
start
Figure 2-3 Two-Stage Charging Process
2–4
Vbat = Vabs
for 1 minute
Vbat = Vgas
for 1 minute
ABS
BULK
CC
Start of
charging cycle
lout < 10% lrating
for 1 minute
GO TO BULK when
Vbat < 12.5 V for
15 minutes
ABS
CV
ABS CV timeout
max 5 hrs
REST (Standby)
timeout max 21 days
Total ABS timeout
max 8 hrs
REST
(Standby)
975-0401-01-01
Time