Full Product Manual

5
Four Charging Stages
The ViewStar charge controllers have a 4-stage battery charging algorithm for a rapid, efficient,
and safe battery charging. They include: Bulk Charge, Boost Charge, Float Charge, and
Equalization.
Bulk Charge: This algorithm is used for day to day charging. It uses 100% of available solar
power to recharge the battery and is equivalent to constant current.
Boost Charge: When the battery has charged to the Boost voltage set-point, it undergoes an
absorption stage which is equivalent to constant voltage regulation to prevent heating and
excessive gassing in the battery. The default time for this is 120 minutes in the ViewStar
controllers but it can be customizable as needed.
Float Charge: After Boost Charge, the controller will reduce the battery voltage to a float
voltage set point. Once the battery is fully charged, there will be no more chemical reactions and
all the charge current would turn into heat or gas. Because of this, the charge controller will reduce
the voltage charge to smaller quantity, while lightly charging the battery. The purpose for this is
to offset the power consumption while maintaining a full battery storage capacity. In the event that
a load drawn from the battery exceeds the charge current, the controller will no longer be able to
maintain the battery to a Float set point and the controller will end the float charge stage and refer
back to bulk charging.
Equalization: Is carried out every 28 days of the month. It is intentional overcharging of the
battery for a controlled period of time. Certain types of batteries benefit from periodic equalizing
charge, which can stir the electrolyte, balance battery voltage and complete chemical reaction.
Equalizing charge increases the battery voltage, higher than the standard complement voltage,
which gasifies the battery electrolyte.