Hawke’s Bay
Manual
23| P a g e 1 0 - 4 2 5 - 1 R E V : - F W : X X X
FET (Field Effect Transistor) temperature reaches 75C, the
Hawke’s Bay
will reduce its
current output on a sliding scale relative to the FET temperature. Or when the current-limit
setpoint is reached, the controller will reduce its current output.
DC Input Modes
•
Solar -
This mode is for PV systems and has a fast sweep (typically 1/2 second or less) that
will re-sweep at user-adjustable sweep intervals, unless the Hawke’s Bay finds that it needs
to do a sweep on its own because of changing conditions. The timed sweep interval is user-
adjustable and is in units of minutes.
ADVANCED SETTINGS & CONCEPTS
•
Charge Time -
For the Absorb timer, use
…
Charge Time = 0.42 X (Bank Ah / Charge rate).
EXAMPLE:
1.
Your battery bank total amp-hour capacity is 400Ah
2.
Your charge controller outputs 65A (This is based on PV wattage / nominal bank
voltage)
3.
Charge Time = 0.42 x (400 Ah / 65A) = 0.42 x 6.15 hours = 2.6 hours.
For the EQ timer, refer to your battery manufacturer specifications.
•
Temperature Compensation (T-comp) -
There is only one setting in the
Hawke’s Bay
that
can influence a different voltage than what you programmed (i.e., Absorb, Float, or EQ) and
that is temperature compensation. As a battery gets colder than 25 degrees Celsius, the
charging voltage needs to be elevated. As a battery gets warmer than 25C, the charging
voltage needs to be lowered. Check with your battery manufacturer and get the following
three values:
1.
Millivolts per degree C per cell to compensate (Default is -5mv).
2.
Reference temperature for the battery (Default is 25C).
3.
The maximum voltage to ever compensate to.
Temperature Offset = Number of cells x T-comp setting (Usually -5mv) x offset in degrees
Celsius from the reference (Typically 25C).
•
Ending Amps -
Used in conjunction with the MidNite Whiz Bang Jr current-sensing device.
Ending amps is set by the battery manufacturer and means the point at which the battery
bank is full. During the Absorb charge cycle, the charge controller holds the voltage at the
preset charge level, say 58.8V. As the batteries fill up, the current into the batteries
decreases. When the decreasing current drops below the preset End Amps point for 90
seconds, the charge controller stops the Absorb cycle and transitions to Float. In the
