Blue Sky Energy - Solar Boost 50
25
SYMPTOM
PROBABLE CAUSE
ITEMS TO EXAMINE OR CORRECT
Charge status LED
blinks rapidly, charge
voltage may be high
System in equalize mode
Disable equalize by pressing the equalize pushbutton.
Charge current is
lower than expected,
PV current may be
low as well
Battery is highly charged
Worn out PV modules
Low insolation
PV- connected to BAT-
MPPT improperly setup
Normal operation, system will be in Acceptance or Float and current is reduced to
control battery voltage.
Replace, or use as is.
Atmospheric haze, PV’s dirty, sun low on horizon, etc.
PV- & BAT- must be separate for proper operation. PV- must receive earth ground
via shunts inside the SB50 which internally connect PV- to BAT-. External
connection prevents proper operation of internal shunts and measurement system.
Verify dip switch #5, verify proper MPPT setup and MPPT trim. See Maximum
Power Voltage and Optimizing MPPT sections.
MPPT Current boost
is less than expected
PV maximum power voltage (V
MP
) is not
much higher than battery voltage, leaving
little extra power to be extracted
PV’s hot
MPPT improperly setup
May result from PV’s with low V
MP
, as PV’s with higher V
MP
produce greater power
and current boost potential. PV’s with V
MP
≥
17V work best, PV’s with <36 cells
tend to work poorly.
Excessive PV wiring voltage drop due to undersize wiring, poor connections etc.,
consumes and wastes available power. This simulates having PV’s with low V
MP
.
Battery is nearly charged and battery voltage is high. Output during MPPT
operation is “constant power”, higher battery voltage decreases charge current.
V
MP
and available power decrease with increasing PV cell temperature. Cooler PV’s
will produce greater boost. MPPT LED off indicates that extra power is not available
from PV array. It is normal for boost to decrease as temperature rises.
Verify dip switch #5, verify proper MPPT setup and MPPT trim. See Maximum
Power Voltage and Optimizing MPPT sections.
System appears OK,
but will not correctly
switch between
Acceptance & Float
Not set for 3 stage charge
System will not switch out of Bulk and into
Acceptance or Float
System will not switch from Float to
Acceptance
System will not switch from Acceptance to
Float
Double check dip switches #10 & 11
Battery is discharged to the point where net charge current cannot bring battery
voltage up to the desired charge voltage setpoint. PV power may be too low or
loads too high.
Battery may be fully charged. System will stay in Float and not switch to
Acceptance until charge current is greater than Float Transition Current setting. See
Float Transition Current Setpoint section. PV array may be too small for battery
amp-hours, consider using 2 stage charge.
External shunt is used and sense wires are wired reverse polarity. Verify charge
current polarity and magnitude using “I BAT” test point. See Float Transition Current
Measurement Shunt and Setpoint sections.
Battery may not be fully charged. System will not switch to Float until charge
current drops to less than the Float Transition Current setpoint during Acceptance.
See Float Transition Current Setpoint section.
Loads during charge may be high while using internal current shunt. Consider using
external shunt. See Float Transition Current Measurement Shunt section.
Relays click on/off
rapidly
Dip switch #12 off
Double check dip switch #12, must always be on. Used for factory test only.
At high ambient
temperature, charge
turns off
System temporarily shuts down due to
high heat sink temperature
Improve ventilation or reduce PV power. Providing sufficient ventilation or operating
conditions which do not cause over temperature shut down will improve reliability.
See Technical Bulletin #
100206.
