Instruction Manual

Charge Controlling
975-0400-01-01 Revision H 1–7
This manual is for use by qualified personnel only.
Two-Stage Battery Charging
The two-stage charging process includes the bulk and absorption stages, but
uses a “No Float” stage instead of “Float.” The relationship between charging
current and battery voltage during the two-stage charging process is shown in
Figure 1-5.
No Float Stage
During the No Float stage the solar charge controller does not produce any
charge current. Instead the solar charge controller monitors the battery voltage
and transitions back to the bulk stage once the voltage drops below the
ReCharge Volts setting for one minute.
Note
: This note is applicable to Figure 1-4 and Figure 1-5.
1. When the charge cycle is interrupted, the charger will restart charging at
the beginning of the multi-stage algorithm.
2. Exit Current Threshold can be effectively disabled by programming the amp
hour capacity to zero. In this case, Absorption will only exit once the Max
Absorption timer expires.
3. Charge current during Equalize state (optional state not shown here) is
normally limited to 10% of the programmed amp hour capacity setting. If
this setting is programmed to zero Ah, the charge current during equalize is
instead limited to whatever is programmed for the max current limit of the
unit (default is 60A).
4. Synchronized charge states are active when more than one charging
device (MPPT or Inv/Chgr) is connected in the system via the Xanbus
network.
i. The first unit to enter Bulk, causes all other chargers to enter Bulk.
ii. The first unit to enter Absorption, causes all other units to enter
Absorption.
iii. The last unit that is ready to exit Absorption, triggers all units to exit
Absorption
and enter Float
Note: For more information about battery charging settings, see Table 3-2 and
Table 3-3.