Xantrex Technology 120 VAC/60 owner manual Charger Mode, Three Stage Charging Process

OPERATION

CHARGER MODE

AC SOURCE AC

CHARGER

DC BATTERY

IN BRIEF

When AC power is available, the inverter can operate as a very powerful battery charger with low current distortion. Power is drawn over the full AC cycle. This improves the performance with low AC input voltage or with small generators.

The SW Series Inverter/Charger includes the ability to automatically “back-off” the battery charger to prevent overloading a generator or tripping a circuit breaker when other AC loads are being operated through the inverter. This improves system reliability and allows greater use of the power available. The charger will also be turned off if the AC voltage drops to an adjustable lower limit VAC setting.

THREE STAGE CHARGING PROCESS

The charging cycle uses three stages. During the initial "Bulk Charge" stage, the inverter charges at maximum rate allowed by the SET MAX CHARGE AMPS AC setting. This causes the battery voltage to rise over time. After the battery voltage nears the SET BULK VOLTS DC setting, the charger starts the second or “Absorption” stage. During this phase, the charge rate is gradually reduced while the battery voltage is held near the bulk voltage setting. This ensures that the battery is fully charged. The final "Float" stage is initiated when the battery has been held near the SET BULK VOLTS DC setting for the adjustable ABSORPTION TIME period setting. At this point, the battery voltage is allowed to fall to the FLOAT VOLTS DC voltage setting, where it is maintained until another bulk charge cycle is initiated. This reduces gassing of the battery and keeps it fully charged. A new three-stage charge cycle is initiated after an AC source is reapplied to the AC HOT input terminals, or daily if the BULK CHARGER TRIGGER TIMER (15) is enabled and if AC power is available continuously.

	Bulk Stage	Absorption Stage		Float Stage
Charging			Bulk Volts Setting
Started
			Absorption Time	Float Volts Setting
DC Voltage	Increased Voltage		Constant Voltage	Reduced Voltage

	Max Charge Amps		If a generator was started automatically by the
	Setting		inverter to charge the battery, it will be shut off when
			the charger reaches the float stage after the
			bulk/absorption period. (GENERATOR must be in
			AUTO mode)
AC Current	Constant Current	Reduced Current	Reduced Current

Time

Figure 21, Three-Stage Battery Charging

Page

64

 2001 Xantrex Technology, Inc.	Telephone: 360/435-8826	SW Series Inverter/Charger
5916 - 195th Street N. E.	Fax: 360/435-2229	Part No. 2031-5
Arlington, WA 98223	www.traceengineering.com	Rev. C: February 2001