MorningStar SunSaver 20 Amp 24 Volt PWM Charge Controller
Options: LVD Override Protection
Manufacturer Part Number: SS-20L-24V
Morningstar's SunSaver (SS-20L-24V) is the world's leading small solar controller for both professional and consumer applications including standard features and capabilities not found in any other small PV controller.
SunSaver’s technology provides:
- Exceptional Reliability
- PWM Battery Charging
- Consistent High Quality
The SunSaver’s advanced design delivers
outstanding performance and value. The
SunSaver’s low cost is made possible by
Morningstar’s unique approach to design
- Automated production
- ISO 9002 quality programs
- Latest power electronic technologies
- Latest control and logic technologies
- High volume manufacturing
It is a fully epoxy encapsulated outdoor rated 10 Amp "ice cube" sized 12V PWM charge controller. It has built-in temperature compensation, lightning protection and easy 4-wire hookup. The SunSavers's regulation voltage is set at 14.1 (best for sealed or gel batteries) and is not adjustable for battery type like MorningStar's other controllers. It's dimensions are 2.5" x 2.0" x 1.5" and it weighs just 3 oz.
- Eight versions available
- 100% solid state
- Series design (not shunt)
- True 0 to 100% PWM duty cycle
- Setpoint accuracy to 35 mV
- Rated for 25% overloads
- Fully encapsulated in epoxy potting
- Marine rated terminals/anodized case
- Temperature compensation
- Sealed/Flooded battery select
- No need to derate
- Parallel for 40 amps or more
- Green charging/Red LVD indicators
- Approved for use in hazardous locations –
Class 1, Division 2, Groups A, B, C, D
||12 Volt||12 Volt||24 Volt||12 Volt||24 Volt|
|Rated Solar Input
|| 6.5 Amps||10 Amps||20 Amps|
||6 Amps||10 Amps||20 Amps|
|25% Current Overload ||5 min|
|| Sealed Battery|
|Flooded Battery||14.1 V
|Load Disconnect|| 11.5 V|| 11.5 V ||23.0 V|| 11.5 V ||23.0 V|
|LVD Reconnect ||12.6 V||12.6 V|| 25.2 V||12.6 V|| 25.2 V|
|Self-consumption ||6 to 10 mA|
|Operating Temp.|| –40 to +85°C|
- Wire size: #10 AWG (5.2 mm2)
- Anodized aluminum case
- Marine rated terminals
- Epoxy encapsulated
- Weight is 8 oz (0.23 kg)
|Standard:|| This item is included.|
|Yes:|| This item is compatible, but not included.|
|No:|| This item is not compatible.|
The SunSaver is rated for 12 volt (or 24 volt) PV systems. Do
not connect to a PV array with open circuit voltage (Voc)
greater than 25 (or 44) volts.
- Maximum array short circuit current rating:
|SUNSAVER-6|| 8.1 amps|
|SUNSAVER-10|| 12.5 amps|
|SUNSAVER-20 ||25.0 amps|
- Because the SunSaver is a series controller, the PV current
rating is specified at the PV array’s peak power (Ipp). The
SunSaver does NOT short the PV array for regulation, and
it is not necessary to derate the controller for short-circuit
current (Isc) as is commonly done with shunt controllers.
- SunSaver models with an automatic low voltage load disconnect
function (LVD) are rated for either 6, 10 or 20 amp loads
depending on the model.
- SunSaver models without an LVD capability are rated for a
maximum load of 10 amps. All loads connected to the SunSaver
LOAD terminals should not exceed 10 amps of current.*
- The rated PV input current and the rated load current can
both be exceeded by 25% for up to 5 minutes. This 25%
overload will reduce the safety margins for surges and will
cause heating that can shorten the life of the controller.
For the reasons noted above, these higher overload ratings
should NOT be used for routine operation. They are only to
note overload capability for system design purposes.
- The SunSaver is designed to operate continuously in 60°C
ambient temperatures. However, do not install the controller
near heat generating sources or in direct sun. This could
cause the temperature rating to be exceeded and damage
- The date of manufacture can be found on the serial number
(bottom of case). The first 4 digits are the year and week.
* It is not necessary to use the SunSaver load
terminals. Loads that exceed the load rating of the
SunSaver can be connected directly to the battery.
- 100% Solid State
All power switching is done with FETs. No mechanical relays
are used in the controller.
- Battery Charge Regulation
SunSaver uses an advanced series PWM charge control for
constant voltage battery charging. A true 0 to 100% PWM
duty cycle is very fast and stable for positive charge control
under all system conditions.
- Temperature Compensation
A sensor next to the green LED measures ambient temperature
conditions. The SunSaver corrects the constant
voltage setpoint –28 (–56 for 24V) mV per °C with a 25°C
reference. This correction matches the battery charging
to the changing electrochemical properties of the battery,
and works best if the battery and controller are in a similar
- Sealed / Flooded Select
Flooded batteries require more vigorous charging to avoid
stratification, and sealed batteries require precise control to
avoid outgassing. The SunSaver constant voltage setpoints
are 14.4 (or 28.8) volts for flooded batteries, and 14.1 (or
28.2) volts for sealed batteries. See Section 5.3-7 for more
- LED Indicators
- Low Voltage Disconnect (LVD)
The automatic load disconnect is an option. If the battery
falls below 11.5 (or 23.0) volts, the load is disconnected from
the battery to protect against harmful deep discharges. A
2-second delay prevents load disconnects from transients.
The load is automatically reconnected when the battery
voltage recovers to 12.6 (or 25.2) volts.
- Battery Disconnect
If the battery is disconnected during the daytime, the PV
array will continue to provide power to the controller. The
SunSaver will immediately go into PWM and provide power
at a constant voltage to the load. This may continue as long
as power is available from the PV array.
- Parallel Controllers
The SunSaver 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 SunSaver’s rating
for PV and load current is not exceeded.
- Auxiliary Generators
Engine generators and other sources of power may be connected
directly to the battery for charging. It is not necessary
to disconnect the SunSaver from the battery. However, do
not use the SunSaver to regulate these other generators.
- Reverse Current
The SunSaver prevents the battery from discharging through
the PV array at night. There is no need to install a blocking
diode for this purpose.
The SunSaver circuit minimizes switching noise and filters
all noise output to extremely low levels when the system
is properly grounded. If noise is present in a telecom load, it
is most likely a grounding problem in the system.
- The SunSaver prevents reverse current leakage at night, so
a blocking diode is not required in the system.
- The connector terminals will accept a maximum wire size
of AWG #10 (up to 5.2 mm2).
- The SunSaver is designed to regulate power from a PV
array. Other generators can be connected directly to the
battery, however, with no effect on the SunSaver.
battery, however, with no effect on the SunSaver.
Warranty: Five year warranty period. Contact Morningstar for complete terms.