Installation Manual

• Sealed / Flooded Select

Flooded batteries require more vigorous charging to avoid strati-

fication, and sealed batteries require precise control to avoid out-

gassing. The SunLight constant voltage setpoints are 14.4 volts

for flooded batteries, and 14.1 volts for 12 volt sealed batteries.

See Section 6.4-7 for more information.

• LED Indicators

See Section 5.0

• Low Voltage Disconnect (LVD)

If the battery falls below 11.7 (or 23.4) volts, the load is discon-

nected from the battery to protect against harmful deep dis-

charges. A one minute delay prevents load disconnects from

transients. The load is automatically reconnected when the bat-

tery voltage recovers to 12.8 (or 25.6) volts.

• Battery Disconnect

If the battery is disconnected during the daytime, the PV array

will continue to provide power to the controller. The SunLight will

immediately go into PWM and provide power at a constant volt-

age to the load. This will continue as long as sufficient power is

available from the PV array.

• Parallel Controllers

Morningstar controllers work very well in parallel configurations.

No blocking diodes are required. The only constraint is that each

controller must have an independent and separate PV subarray

and load. Make sure that each controller’s rating for PV and load

current is not exceeded.

• Auxiliary Generators

Engine generators and other sources of power may be connect-

ed directly to the battery for charging. It is not necessary to dis-

connect the SunLight from the battery. However, do not use the

SunLight to regulate these other generators.

• Reverse Current

The SunLight prevents the battery from discharging through the

PV array at night. There is no need to install a blocking diode for

this purpose.