• 100% solid state

• Fully encapsulated in epoxy potting

• Marine rated terminals/anodized case

• Series design (not shunt)

• True 0 to 100% PWM duty cycle

• Setpoint accuracy to 12V: +/- 25mV, 24V: +/- 48mV

• Rated for 25% overloads

• Temperature compensation

• Sealed/Flooded battery select

• No need to derate

• Parallel for 40 amps or more

• Green charging/Red LVD indicators

• Weight is 8 oz (0.23 kg)

Electrical Specifications:

Model                              SS-20L-12V               SS-20L-24V

Max Solar Current        20 Amps                      20 Amps

Max Load Current        20 Amps                      20 Amps

Regulation Voltage:    

                    Sealed       14.1 Volts                    28.2 Volts

                    Flooded     14.4 Volts                    28.8 Volts

Load Disconnect         11.5 Volts                    23.0 Volts

LVD Reconnect           12.6 Volts                    25.2 Volts

Max PV Volts                25 Volts                       44 Volts

Self Consumption                         6 to 10 mA

Operating Temperature            -40 to +60 C.

Wire size                                       #10 AWG


  • 100% Solid State: All power switching is done with FETs. No mechanical relays are used in the controller.
  • Battery Charge Regulation: 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. 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 thermal environment.
  • Sealed / Flooded Select: Flooded batteries require more vigorous charging to avoid stratification, and sealed batteries require precise control to avoid outgassing. Constant voltage setpoints are 14.4 (or 28.8) volts for flooded batteries, and 14.1 (or 28.2) volts for sealed batteries. 
  • 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. 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: 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 controllers 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 controller from the battery. However, do not use the controller to regulate these other generators.
  • Reverse Current: Prevents the battery from discharging through the PV array at night. There is no need to install a blocking diode for this purpose.
  • Noise: The controllers 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.

12 or 24 Volt 20A Charge Controller: 

$95 Postpaid to USA.   

$105 Postpaid to other countries Worldwide.