30 Truecharge2 Series Battery Charger Owner’s Guide

Installing Batteries
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 9V (12 Vdc chargers) or 18V
(24Vdc 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 12.5V (12 Vdc
chargers) or 25V (24 Vdc chargers) for 15 minutes. After seven days, the
charger will automatically restart charging in order to refresh the batteries.
Figure 10
Two-Stage Charging Process
BatteryVoltage
Time
ABS
CC
ABS
CV
REST
(Standby)
ABS CV timeout
max 5 hrs
REST (Standby)
timeout max 7 days
TotalABS timeout
max 8 hrs
BULK
Vgas voltage
Vbat = Vgas
for 1 minute
GO TO BULK when
Vbat < 12.5 V for
15 minutes
Vbat =Vabs
for 1 minute for 1 minute
lout < 10% lrating
Charge
start
Start of
charging cycle
TC2 204060 Series BattChg Owners Guide.book Page 30 Friday, July 8, 2011 11:44 AM